26778 Commits

Author SHA1 Message Date
Rickard x Andersson
ed8d556f31 gcov: add support for checksum field
commit e96b95c2b7a63a454b6498e2df67aac14d046d13 upstream.

In GCC version 12.1 a checksum field was added.

This patch fixes a kernel crash occurring during boot when using
gcov-kernel with GCC version 12.2.  The crash occurred on a system running
on i.MX6SX.

Link: https://lkml.kernel.org/r/20221220102318.3418501-1-rickaran@axis.com
Fixes: 977ef30a7d88 ("gcov: support GCC 12.1 and newer compilers")
Signed-off-by: Rickard x Andersson <rickaran@axis.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Tested-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Martin Liska <mliska@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-18 09:26:35 +01:00
Zheng Yejian
cf60bbca1b acct: fix potential integer overflow in encode_comp_t()
[ Upstream commit c5f31c655bcc01b6da53b836ac951c1556245305 ]

The integer overflow is descripted with following codes:
  > 317 static comp_t encode_comp_t(u64 value)
  > 318 {
  > 319         int exp, rnd;
    ......
  > 341         exp <<= MANTSIZE;
  > 342         exp += value;
  > 343         return exp;
  > 344 }

Currently comp_t is defined as type of '__u16', but the variable 'exp' is
type of 'int', so overflow would happen when variable 'exp' in line 343 is
greater than 65535.

Link: https://lkml.kernel.org/r/20210515140631.369106-3-zhengyejian1@huawei.com
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zhang Jinhao <zhangjinhao2@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-18 09:26:30 +01:00
Yang Jihong
82f2a5b6aa blktrace: Fix output non-blktrace event when blk_classic option enabled
[ Upstream commit f596da3efaf4130ff61cd029558845808df9bf99 ]

When the blk_classic option is enabled, non-blktrace events must be
filtered out. Otherwise, events of other types are output in the blktrace
classic format, which is unexpected.

The problem can be triggered in the following ways:

  # echo 1 > /sys/kernel/debug/tracing/options/blk_classic
  # echo 1 > /sys/kernel/debug/tracing/events/enable
  # echo blk > /sys/kernel/debug/tracing/current_tracer
  # cat /sys/kernel/debug/tracing/trace_pipe

Fixes: c71a89615411 ("blktrace: add ftrace plugin")
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/r/20221122040410.85113-1-yangjihong1@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-18 09:26:18 +01:00
Chen Zhongjin
6681f6e3a6 perf: Fix possible memleak in pmu_dev_alloc()
[ Upstream commit e8d7a90c08ce963c592fb49845f2ccc606a2ac21 ]

In pmu_dev_alloc(), when dev_set_name() failed, it will goto free_dev
and call put_device(pmu->dev) to release it.
However pmu->dev->release is assigned after this, which makes warning
and memleak.
Call dev_set_name() after pmu->dev->release = pmu_dev_release to fix it.

  Device '(null)' does not have a release() function...
  WARNING: CPU: 2 PID: 441 at drivers/base/core.c:2332 device_release+0x1b9/0x240
  ...
  Call Trace:
    <TASK>
    kobject_put+0x17f/0x460
    put_device+0x20/0x30
    pmu_dev_alloc+0x152/0x400
    perf_pmu_register+0x96b/0xee0
    ...
  kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
  unreferenced object 0xffff888014759000 (size 2048):
    comm "modprobe", pid 441, jiffies 4294931444 (age 38.332s)
    backtrace:
      [<0000000005aed3b4>] kmalloc_trace+0x27/0x110
      [<000000006b38f9b8>] pmu_dev_alloc+0x50/0x400
      [<00000000735f17be>] perf_pmu_register+0x96b/0xee0
      [<00000000e38477f1>] 0xffffffffc0ad8603
      [<000000004e162216>] do_one_initcall+0xd0/0x4e0
      ...

Fixes: abe43400579d ("perf: Sysfs enumeration")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221111103653.91058-1-chenzhongjin@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-18 09:26:09 +01:00
xiongxin
6117eab955 PM: hibernate: Fix mistake in kerneldoc comment
[ Upstream commit 6e5d7300cbe7c3541bc31f16db3e9266e6027b4b ]

The actual maximum image size formula in hibernate_preallocate_memory()
is as follows:

max_size = (count - (size + PAGES_FOR_IO)) / 2
	    - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);

but the one in the kerneldoc comment of the function is different and
incorrect.

Fixes: ddeb64870810 ("PM / Hibernate: Add sysfs knob to control size of memory for drivers")
Signed-off-by: xiongxin <xiongxin@kylinos.cn>
[ rjw: Subject and changelog rewrite ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-18 09:26:09 +01:00
Tejun Heo
b77600e26f memcg: fix possible use-after-free in memcg_write_event_control()
commit 4a7ba45b1a435e7097ca0f79a847d0949d0eb088 upstream.

memcg_write_event_control() accesses the dentry->d_name of the specified
control fd to route the write call.  As a cgroup interface file can't be
renamed, it's safe to access d_name as long as the specified file is a
regular cgroup file.  Also, as these cgroup interface files can't be
removed before the directory, it's safe to access the parent too.

Prior to 347c4a874710 ("memcg: remove cgroup_event->cft"), there was a
call to __file_cft() which verified that the specified file is a regular
cgroupfs file before further accesses.  The cftype pointer returned from
__file_cft() was no longer necessary and the commit inadvertently dropped
the file type check with it allowing any file to slip through.  With the
invarients broken, the d_name and parent accesses can now race against
renames and removals of arbitrary files and cause use-after-free's.

Fix the bug by resurrecting the file type check in __file_cft().  Now that
cgroupfs is implemented through kernfs, checking the file operations needs
to go through a layer of indirection.  Instead, let's check the superblock
and dentry type.

Link: https://lkml.kernel.org/r/Y5FRm/cfcKPGzWwl@slm.duckdns.org
Fixes: 347c4a874710 ("memcg: remove cgroup_event->cft")
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jann Horn <jannh@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: <stable@vger.kernel.org>	[3.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-14 11:26:13 +01:00
Linus Torvalds
dad6ca557f proc: proc_skip_spaces() shouldn't think it is working on C strings
commit bce9332220bd677d83b19d21502776ad555a0e73 upstream.

proc_skip_spaces() seems to think it is working on C strings, and ends
up being just a wrapper around skip_spaces() with a really odd calling
convention.

Instead of basing it on skip_spaces(), it should have looked more like
proc_skip_char(), which really is the exact same function (except it
skips a particular character, rather than whitespace).  So use that as
inspiration, odd coding and all.

Now the calling convention actually makes sense and works for the
intended purpose.

Reported-and-tested-by: Kyle Zeng <zengyhkyle@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-08 11:16:33 +01:00
Linus Torvalds
4f4ff21bbc proc: avoid integer type confusion in get_proc_long
commit e6cfaf34be9fcd1a8285a294e18986bfc41a409c upstream.

proc_get_long() is passed a size_t, but then assigns it to an 'int'
variable for the length.  Let's not do that, even if our IO paths are
limited to MAX_RW_COUNT (exactly because of these kinds of type errors).

So do the proper test in the rigth type.

Reported-by: Kyle Zeng <zengyhkyle@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-08 11:16:33 +01:00
Kan Liang
86a4ce251f perf: Add sample_flags to indicate the PMU-filled sample data
[ Upstream commit 3aac580d5cc3001ca1627725b3b61edb529f341d ]

On some platforms, some data e.g., timestamps, can be retrieved from
the PMU driver. Usually, the data from the PMU driver is more accurate.
The current perf kernel should output the PMU-filled sample data if
it's available.

To check the availability of the PMU-filled sample data, the current
perf kernel initializes the related fields in the
perf_sample_data_init(). When outputting a sample, the perf checks
whether the field is updated by the PMU driver. If yes, the updated
value will be output. If not, the perf uses an SW way to calculate the
value or just outputs the initialized value if an SW way is unavailable
either.

With more and more data being provided by the PMU driver, more fields
has to be initialized in the perf_sample_data_init(). That will
increase the number of cache lines touched in perf_sample_data_init()
and be harmful to the performance.

Add new "sample_flags" to indicate the PMU-filled sample data. The PMU
driver should set the corresponding PERF_SAMPLE_ flag when the field is
updated. The initialization of the corresponding field is not required
anymore. The following patches will make use of it and remove the
corresponding fields from the perf_sample_data_init(), which will
further minimize the number of cache lines touched.

Only clear the sample flags that have already been done by the PMU
driver in the perf_prepare_sample() for the PERF_RECORD_SAMPLE. For the
other PERF_RECORD_ event type, the sample data is not available.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220901130959.1285717-2-kan.liang@linux.intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08 11:16:32 +01:00
Daniil Tatianin
4c9338db7d ring_buffer: Do not deactivate non-existant pages
commit 56f4ca0a79a9f1af98f26c54b9b89ba1f9bcc6bd upstream.

rb_head_page_deactivate() expects cpu_buffer to contain a valid list of
->pages, so verify that the list is actually present before calling it.

Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.

Link: https://lkml.kernel.org/r/20221114143129.3534443-1-d-tatianin@yandex-team.ru

Cc: stable@vger.kernel.org
Fixes: 77ae365eca895 ("ring-buffer: make lockless")
Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-25 17:36:51 +01:00
Xiu Jianfeng
665b4c6648 ftrace: Fix null pointer dereference in ftrace_add_mod()
commit 19ba6c8af9382c4c05dc6a0a79af3013b9a35cd0 upstream.

The @ftrace_mod is allocated by kzalloc(), so both the members {prev,next}
of @ftrace_mode->list are NULL, it's not a valid state to call list_del().
If kstrdup() for @ftrace_mod->{func|module} fails, it goes to @out_free
tag and calls free_ftrace_mod() to destroy @ftrace_mod, then list_del()
will write prev->next and next->prev, where null pointer dereference
happens.

BUG: kernel NULL pointer dereference, address: 0000000000000008
Oops: 0002 [#1] PREEMPT SMP NOPTI
Call Trace:
 <TASK>
 ftrace_mod_callback+0x20d/0x220
 ? do_filp_open+0xd9/0x140
 ftrace_process_regex.isra.51+0xbf/0x130
 ftrace_regex_write.isra.52.part.53+0x6e/0x90
 vfs_write+0xee/0x3a0
 ? __audit_filter_op+0xb1/0x100
 ? auditd_test_task+0x38/0x50
 ksys_write+0xa5/0xe0
 do_syscall_64+0x3a/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
Kernel panic - not syncing: Fatal exception

So call INIT_LIST_HEAD() to initialize the list member to fix this issue.

Link: https://lkml.kernel.org/r/20221116015207.30858-1-xiujianfeng@huawei.com

Cc: stable@vger.kernel.org
Fixes: 673feb9d76ab ("ftrace: Add :mod: caching infrastructure to trace_array")
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-25 17:36:51 +01:00
Wang Wensheng
7eb7b34275 ftrace: Optimize the allocation for mcount entries
commit bcea02b096333dc74af987cb9685a4dbdd820840 upstream.

If we can't allocate this size, try something smaller with half of the
size. Its order should be decreased by one instead of divided by two.

Link: https://lkml.kernel.org/r/20221109094434.84046-3-wangwensheng4@huawei.com

Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Fixes: a79008755497d ("ftrace: Allocate the mcount record pages as groups")
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-25 17:36:51 +01:00
Wang Wensheng
c07fd1115d ftrace: Fix the possible incorrect kernel message
commit 08948caebe93482db1adfd2154eba124f66d161d upstream.

If the number of mcount entries is an integer multiple of
ENTRIES_PER_PAGE, the page count showing on the console would be wrong.

Link: https://lkml.kernel.org/r/20221109094434.84046-2-wangwensheng4@huawei.com

Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Fixes: 5821e1b74f0d0 ("function tracing: fix wrong pos computing when read buffer has been fulfilled")
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-25 17:36:51 +01:00
Mario Limonciello
7952605f20 PM: hibernate: Allow hybrid sleep to work with s2idle
[ Upstream commit 85850af4fc47132f3f2f0dd698b90f67906600b4 ]

Hybrid sleep is currently hardcoded to only operate with S3 even
on systems that might not support it.

Instead of assuming this mode is what the user wants to use, for
hybrid sleep follow the setting of `mem_sleep_current` which
will respect mem_sleep_default kernel command line and policy
decisions made by the presence of the FADT low power idle bit.

Fixes: 81d45bdf8913 ("PM / hibernate: Untangle power_down()")
Reported-and-tested-by: kolAflash <kolAflash@kolahilft.de>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216574
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-03 23:50:55 +09:00
Martin Liska
e0b0304702 gcov: support GCC 12.1 and newer compilers
commit 977ef30a7d888eeb52fb6908f99080f33e5309a8 upstream.

Starting with GCC 12.1, the created .gcda format can't be read by gcov
tool.  There are 2 significant changes to the .gcda file format that
need to be supported:

a) [gcov: Use system IO buffering]
   (23eb66d1d46a34cb28c4acbdf8a1deb80a7c5a05) changed that all sizes in
   the format are in bytes and not in words (4B)

b) [gcov: make profile merging smarter]
   (72e0c742bd01f8e7e6dcca64042b9ad7e75979de) add a new checksum to the
   file header.

Tested with GCC 7.5, 10.4, 12.2 and the current master.

Link: https://lkml.kernel.org/r/624bda92-f307-30e9-9aaa-8cc678b2dfb2@suse.cz
Signed-off-by: Martin Liska <mliska@suse.cz>
Tested-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:16:58 +02:00
Steven Rostedt (Google)
2b261933e2 ring-buffer: Fix race between reset page and reading page
commit a0fcaaed0c46cf9399d3a2d6e0c87ddb3df0e044 upstream.

The ring buffer is broken up into sub buffers (currently of page size).
Each sub buffer has a pointer to its "tail" (the last event written to the
sub buffer). When a new event is requested, the tail is locally
incremented to cover the size of the new event. This is done in a way that
there is no need for locking.

If the tail goes past the end of the sub buffer, the process of moving to
the next sub buffer takes place. After setting the current sub buffer to
the next one, the previous one that had the tail go passed the end of the
sub buffer needs to be reset back to the original tail location (before
the new event was requested) and the rest of the sub buffer needs to be
"padded".

The race happens when a reader takes control of the sub buffer. As readers
do a "swap" of sub buffers from the ring buffer to get exclusive access to
the sub buffer, it replaces the "head" sub buffer with an empty sub buffer
that goes back into the writable portion of the ring buffer. This swap can
happen as soon as the writer moves to the next sub buffer and before it
updates the last sub buffer with padding.

Because the sub buffer can be released to the reader while the writer is
still updating the padding, it is possible for the reader to see the event
that goes past the end of the sub buffer. This can cause obvious issues.

To fix this, add a few memory barriers so that the reader definitely sees
the updates to the sub buffer, and also waits until the writer has put
back the "tail" of the sub buffer back to the last event that was written
on it.

To be paranoid, it will only spin for 1 second, otherwise it will
warn and shutdown the ring buffer code. 1 second should be enough as
the writer does have preemption disabled. If the writer doesn't move
within 1 second (with preemption disabled) something is horribly
wrong. No interrupt should last 1 second!

Link: https://lore.kernel.org/all/20220830120854.7545-1-jiazi.li@transsion.com/
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216369
Link: https://lkml.kernel.org/r/20220929104909.0650a36c@gandalf.local.home

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Fixes: c7b0930857e22 ("ring-buffer: prevent adding write in discarded area")
Reported-by: Jiazi.Li <jiazi.li@transsion.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:16:58 +02:00
Steven Rostedt (Google)
7240e7d0c2 ring-buffer: Check pending waiters when doing wake ups as well
commit ec0bbc5ec5664dcee344f79373852117dc672c86 upstream.

The wake up waiters only checks the "wakeup_full" variable and not the
"full_waiters_pending". The full_waiters_pending is set when a waiter is
added to the wait queue. The wakeup_full is only set when an event is
triggered, and it clears the full_waiters_pending to avoid multiple calls
to irq_work_queue().

The irq_work callback really needs to check both wakeup_full as well as
full_waiters_pending such that this code can be used to wake up waiters
when a file is closed that represents the ring buffer and the waiters need
to be woken up.

Link: https://lkml.kernel.org/r/20220927231824.209460321@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 15693458c4bc0 ("tracing/ring-buffer: Move poll wake ups into ring buffer code")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:16:58 +02:00
Steven Rostedt (Google)
5623aad6cd ring-buffer: Allow splice to read previous partially read pages
commit fa8f4a89736b654125fb254b0db753ac68a5fced upstream.

If a page is partially read, and then the splice system call is run
against the ring buffer, it will always fail to read, no matter how much
is in the ring buffer. That's because the code path for a partial read of
the page does will fail if the "full" flag is set.

The splice system call wants full pages, so if the read of the ring buffer
is not yet full, it should return zero, and the splice will block. But if
a previous read was done, where the beginning has been consumed, it should
still be given to the splice caller if the rest of the page has been
written to.

This caused the splice command to never consume data in this scenario, and
let the ring buffer just fill up and lose events.

Link: https://lkml.kernel.org/r/20220927144317.46be6b80@gandalf.local.home

Cc: stable@vger.kernel.org
Fixes: 8789a9e7df6bf ("ring-buffer: read page interface")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:16:58 +02:00
Zheng Yejian
caeaffa62d ftrace: Properly unset FTRACE_HASH_FL_MOD
commit 0ce0638edf5ec83343302b884fa208179580700a upstream.

When executing following commands like what document said, but the log
"#### all functions enabled ####" was not shown as expect:
  1. Set a 'mod' filter:
    $ echo 'write*:mod:ext3' > /sys/kernel/tracing/set_ftrace_filter
  2. Invert above filter:
    $ echo '!write*:mod:ext3' >> /sys/kernel/tracing/set_ftrace_filter
  3. Read the file:
    $ cat /sys/kernel/tracing/set_ftrace_filter

By some debugging, I found that flag FTRACE_HASH_FL_MOD was not unset
after inversion like above step 2 and then result of ftrace_hash_empty()
is incorrect.

Link: https://lkml.kernel.org/r/20220926152008.2239274-1-zhengyejian1@huawei.com

Cc: <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 8c08f0d5c6fb ("ftrace: Have cached module filters be an active filter")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:16:57 +02:00
Rik van Riel
c94203f462 livepatch: fix race between fork and KLP transition
commit 747f7a2901174c9afa805dddfb7b24db6f65e985 upstream.

The KLP transition code depends on the TIF_PATCH_PENDING and
the task->patch_state to stay in sync. On a normal (forward)
transition, TIF_PATCH_PENDING will be set on every task in
the system, while on a reverse transition (after a failed
forward one) first TIF_PATCH_PENDING will be cleared from
every task, followed by it being set on tasks that need to
be transitioned back to the original code.

However, the fork code copies over the TIF_PATCH_PENDING flag
from the parent to the child early on, in dup_task_struct and
setup_thread_stack. Much later, klp_copy_process will set
child->patch_state to match that of the parent.

However, the parent's patch_state may have been changed by KLP loading
or unloading since it was initially copied over into the child.

This results in the KLP code occasionally hitting this warning in
klp_complete_transition:

        for_each_process_thread(g, task) {
                WARN_ON_ONCE(test_tsk_thread_flag(task, TIF_PATCH_PENDING));
                task->patch_state = KLP_UNDEFINED;
        }

Set, or clear, the TIF_PATCH_PENDING flag in the child task
depending on whether or not it is needed at the time
klp_copy_process is called, at a point in copy_process where the
tasklist_lock is held exclusively, preventing races with the KLP
code.

The KLP code does have a few places where the state is changed
without the tasklist_lock held, but those should not cause
problems because klp_update_patch_state(current) cannot be
called while the current task is in the middle of fork,
klp_check_and_switch_task() which is called under the pi_lock,
which prevents rescheduling, and manipulation of the patch
state of idle tasks, which do not fork.

This should prevent this warning from triggering again in the
future, and close the race for both normal and reverse transitions.

Signed-off-by: Rik van Riel <riel@surriel.com>
Reported-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Fixes: d83a7cb375ee ("livepatch: change to a per-task consistency model")
Cc: stable@kernel.org
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220808150019.03d6a67b@imladris.surriel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:16:57 +02:00
Christian A. Ehrhardt
985abab0e7 kprobes: Prohibit probes in gate area
commit 1efda38d6f9ba26ac88b359c6277f1172db03f1e upstream.

The system call gate area counts as kernel text but trying
to install a kprobe in this area fails with an Oops later on.
To fix this explicitly disallow the gate area for kprobes.

Found by syzkaller with the following reproducer:
perf_event_open$cgroup(&(0x7f00000001c0)={0x6, 0x80, 0x0, 0x0, 0x0, 0x0, 0x80ffff, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, @perf_config_ext={0x0, 0xffffffffff600000}}, 0xffffffffffffffff, 0x0, 0xffffffffffffffff, 0x0)

Sample report:
BUG: unable to handle page fault for address: fffffbfff3ac6000
PGD 6dfcb067 P4D 6dfcb067 PUD 6df8f067 PMD 6de4d067 PTE 0
Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 PID: 21978 Comm: syz-executor.2 Not tainted 6.0.0-rc3-00363-g7726d4c3e60b-dirty #6
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:__insn_get_emulate_prefix arch/x86/lib/insn.c:91 [inline]
RIP: 0010:insn_get_emulate_prefix arch/x86/lib/insn.c:106 [inline]
RIP: 0010:insn_get_prefixes.part.0+0xa8/0x1110 arch/x86/lib/insn.c:134
Code: 49 be 00 00 00 00 00 fc ff df 48 8b 40 60 48 89 44 24 08 e9 81 00 00 00 e8 e5 4b 39 ff 4c 89 fa 4c 89 f9 48 c1 ea 03 83 e1 07 <42> 0f b6 14 32 38 ca 7f 08 84 d2 0f 85 06 10 00 00 48 89 d8 48 89
RSP: 0018:ffffc900088bf860 EFLAGS: 00010246
RAX: 0000000000040000 RBX: ffffffff9b9bebc0 RCX: 0000000000000000
RDX: 1ffffffff3ac6000 RSI: ffffc90002d82000 RDI: ffffc900088bf9e8
RBP: ffffffff9d630001 R08: 0000000000000000 R09: ffffc900088bf9e8
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001
R13: ffffffff9d630000 R14: dffffc0000000000 R15: ffffffff9d630000
FS:  00007f63eef63640(0000) GS:ffff88806d000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfff3ac6000 CR3: 0000000029d90005 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
 <TASK>
 insn_get_prefixes arch/x86/lib/insn.c:131 [inline]
 insn_get_opcode arch/x86/lib/insn.c:272 [inline]
 insn_get_modrm+0x64a/0x7b0 arch/x86/lib/insn.c:343
 insn_get_sib+0x29a/0x330 arch/x86/lib/insn.c:421
 insn_get_displacement+0x350/0x6b0 arch/x86/lib/insn.c:464
 insn_get_immediate arch/x86/lib/insn.c:632 [inline]
 insn_get_length arch/x86/lib/insn.c:707 [inline]
 insn_decode+0x43a/0x490 arch/x86/lib/insn.c:747
 can_probe+0xfc/0x1d0 arch/x86/kernel/kprobes/core.c:282
 arch_prepare_kprobe+0x79/0x1c0 arch/x86/kernel/kprobes/core.c:739
 prepare_kprobe kernel/kprobes.c:1160 [inline]
 register_kprobe kernel/kprobes.c:1641 [inline]
 register_kprobe+0xb6e/0x1690 kernel/kprobes.c:1603
 __register_trace_kprobe kernel/trace/trace_kprobe.c:509 [inline]
 __register_trace_kprobe+0x26a/0x2d0 kernel/trace/trace_kprobe.c:477
 create_local_trace_kprobe+0x1f7/0x350 kernel/trace/trace_kprobe.c:1833
 perf_kprobe_init+0x18c/0x280 kernel/trace/trace_event_perf.c:271
 perf_kprobe_event_init+0xf8/0x1c0 kernel/events/core.c:9888
 perf_try_init_event+0x12d/0x570 kernel/events/core.c:11261
 perf_init_event kernel/events/core.c:11325 [inline]
 perf_event_alloc.part.0+0xf7f/0x36a0 kernel/events/core.c:11619
 perf_event_alloc kernel/events/core.c:12059 [inline]
 __do_sys_perf_event_open+0x4a8/0x2a00 kernel/events/core.c:12157
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f63ef7efaed
Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f63eef63028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f63ef90ff80 RCX: 00007f63ef7efaed
RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 00000000200001c0
RBP: 00007f63ef86019c R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000002 R14: 00007f63ef90ff80 R15: 00007f63eef43000
 </TASK>
Modules linked in:
CR2: fffffbfff3ac6000
---[ end trace 0000000000000000 ]---
RIP: 0010:__insn_get_emulate_prefix arch/x86/lib/insn.c:91 [inline]
RIP: 0010:insn_get_emulate_prefix arch/x86/lib/insn.c:106 [inline]
RIP: 0010:insn_get_prefixes.part.0+0xa8/0x1110 arch/x86/lib/insn.c:134
Code: 49 be 00 00 00 00 00 fc ff df 48 8b 40 60 48 89 44 24 08 e9 81 00 00 00 e8 e5 4b 39 ff 4c 89 fa 4c 89 f9 48 c1 ea 03 83 e1 07 <42> 0f b6 14 32 38 ca 7f 08 84 d2 0f 85 06 10 00 00 48 89 d8 48 89
RSP: 0018:ffffc900088bf860 EFLAGS: 00010246
RAX: 0000000000040000 RBX: ffffffff9b9bebc0 RCX: 0000000000000000
RDX: 1ffffffff3ac6000 RSI: ffffc90002d82000 RDI: ffffc900088bf9e8
RBP: ffffffff9d630001 R08: 0000000000000000 R09: ffffc900088bf9e8
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001
R13: ffffffff9d630000 R14: dffffc0000000000 R15: ffffffff9d630000
FS:  00007f63eef63640(0000) GS:ffff88806d000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfff3ac6000 CR3: 0000000029d90005 CR4: 0000000000770ef0
PKRU: 55555554
==================================================================

Link: https://lkml.kernel.org/r/20220907200917.654103-1-lk@c--e.de

cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
cc: "David S. Miller" <davem@davemloft.net>
Cc: stable@vger.kernel.org
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-15 12:23:52 +02:00
John Fastabend
a7cf53f9eb bpf: Verifer, adjust_scalar_min_max_vals to always call update_reg_bounds()
commit 294f2fc6da27620a506e6c050241655459ccd6bd upstream.

Currently, for all op verification we call __red_deduce_bounds() and
__red_bound_offset() but we only call __update_reg_bounds() in bitwise
ops. However, we could benefit from calling __update_reg_bounds() in
BPF_ADD, BPF_SUB, and BPF_MUL cases as well.

For example, a register with state 'R1_w=invP0' when we subtract from
it,

 w1 -= 2

Before coerce we will now have an smin_value=S64_MIN, smax_value=U64_MAX
and unsigned bounds umin_value=0, umax_value=U64_MAX. These will then
be clamped to S32_MIN, U32_MAX values by coerce in the case of alu32 op
as done in above example. However tnum will be a constant because the
ALU op is done on a constant.

Without update_reg_bounds() we have a scenario where tnum is a const
but our unsigned bounds do not reflect this. By calling update_reg_bounds
after coerce to 32bit we further refine the umin_value to U64_MAX in the
alu64 case or U32_MAX in the alu32 case above.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/158507151689.15666.566796274289413203.stgit@john-Precision-5820-Tower
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-15 12:23:49 +02:00
Kuniyuki Iwashima
6f3c1bc22f kprobes: don't call disarm_kprobe() for disabled kprobes
commit 9c80e79906b4ca440d09e7f116609262bb747909 upstream.

The assumption in __disable_kprobe() is wrong, and it could try to disarm
an already disarmed kprobe and fire the WARN_ONCE() below. [0]  We can
easily reproduce this issue.

1. Write 0 to /sys/kernel/debug/kprobes/enabled.

  # echo 0 > /sys/kernel/debug/kprobes/enabled

2. Run execsnoop.  At this time, one kprobe is disabled.

  # /usr/share/bcc/tools/execsnoop &
  [1] 2460
  PCOMM            PID    PPID   RET ARGS

  # cat /sys/kernel/debug/kprobes/list
  ffffffff91345650  r  __x64_sys_execve+0x0    [FTRACE]
  ffffffff91345650  k  __x64_sys_execve+0x0    [DISABLED][FTRACE]

3. Write 1 to /sys/kernel/debug/kprobes/enabled, which changes
   kprobes_all_disarmed to false but does not arm the disabled kprobe.

  # echo 1 > /sys/kernel/debug/kprobes/enabled

  # cat /sys/kernel/debug/kprobes/list
  ffffffff91345650  r  __x64_sys_execve+0x0    [FTRACE]
  ffffffff91345650  k  __x64_sys_execve+0x0    [DISABLED][FTRACE]

4. Kill execsnoop, when __disable_kprobe() calls disarm_kprobe() for the
   disabled kprobe and hits the WARN_ONCE() in __disarm_kprobe_ftrace().

  # fg
  /usr/share/bcc/tools/execsnoop
  ^C

Actually, WARN_ONCE() is fired twice, and __unregister_kprobe_top() misses
some cleanups and leaves the aggregated kprobe in the hash table.  Then,
__unregister_trace_kprobe() initialises tk->rp.kp.list and creates an
infinite loop like this.

  aggregated kprobe.list -> kprobe.list -.
                                     ^    |
                                     '.__.'

In this situation, these commands fall into the infinite loop and result
in RCU stall or soft lockup.

  cat /sys/kernel/debug/kprobes/list : show_kprobe_addr() enters into the
                                       infinite loop with RCU.

  /usr/share/bcc/tools/execsnoop : warn_kprobe_rereg() holds kprobe_mutex,
                                   and __get_valid_kprobe() is stuck in
				   the loop.

To avoid the issue, make sure we don't call disarm_kprobe() for disabled
kprobes.

[0]
Failed to disarm kprobe-ftrace at __x64_sys_execve+0x0/0x40 (error -2)
WARNING: CPU: 6 PID: 2460 at kernel/kprobes.c:1130 __disarm_kprobe_ftrace.isra.19 (kernel/kprobes.c:1129)
Modules linked in: ena
CPU: 6 PID: 2460 Comm: execsnoop Not tainted 5.19.0+ #28
Hardware name: Amazon EC2 c5.2xlarge/, BIOS 1.0 10/16/2017
RIP: 0010:__disarm_kprobe_ftrace.isra.19 (kernel/kprobes.c:1129)
Code: 24 8b 02 eb c1 80 3d c4 83 f2 01 00 75 d4 48 8b 75 00 89 c2 48 c7 c7 90 fa 0f 92 89 04 24 c6 05 ab 83 01 e8 e4 94 f0 ff <0f> 0b 8b 04 24 eb b1 89 c6 48 c7 c7 60 fa 0f 92 89 04 24 e8 cc 94
RSP: 0018:ffff9e6ec154bd98 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffffffff930f7b00 RCX: 0000000000000001
RDX: 0000000080000001 RSI: ffffffff921461c5 RDI: 00000000ffffffff
RBP: ffff89c504286da8 R08: 0000000000000000 R09: c0000000fffeffff
R10: 0000000000000000 R11: ffff9e6ec154bc28 R12: ffff89c502394e40
R13: ffff89c502394c00 R14: ffff9e6ec154bc00 R15: 0000000000000000
FS:  00007fe800398740(0000) GS:ffff89c812d80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c00057f010 CR3: 0000000103b54006 CR4: 00000000007706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
 __disable_kprobe (kernel/kprobes.c:1716)
 disable_kprobe (kernel/kprobes.c:2392)
 __disable_trace_kprobe (kernel/trace/trace_kprobe.c:340)
 disable_trace_kprobe (kernel/trace/trace_kprobe.c:429)
 perf_trace_event_unreg.isra.2 (./include/linux/tracepoint.h:93 kernel/trace/trace_event_perf.c:168)
 perf_kprobe_destroy (kernel/trace/trace_event_perf.c:295)
 _free_event (kernel/events/core.c:4971)
 perf_event_release_kernel (kernel/events/core.c:5176)
 perf_release (kernel/events/core.c:5186)
 __fput (fs/file_table.c:321)
 task_work_run (./include/linux/sched.h:2056 (discriminator 1) kernel/task_work.c:179 (discriminator 1))
 exit_to_user_mode_prepare (./include/linux/resume_user_mode.h:49 kernel/entry/common.c:169 kernel/entry/common.c:201)
 syscall_exit_to_user_mode (./arch/x86/include/asm/jump_label.h:55 ./arch/x86/include/asm/nospec-branch.h:384 ./arch/x86/include/asm/entry-common.h:94 kernel/entry/common.c:133 kernel/entry/common.c:296)
 do_syscall_64 (arch/x86/entry/common.c:87)
 entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
RIP: 0033:0x7fe7ff210654
Code: 15 79 89 20 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb be 0f 1f 00 8b 05 9a cd 20 00 48 63 ff 85 c0 75 11 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 3a f3 c3 48 83 ec 18 48 89 7c 24 08 e8 34 fc
RSP: 002b:00007ffdbd1d3538 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000008 RCX: 00007fe7ff210654
RDX: 0000000000000000 RSI: 0000000000002401 RDI: 0000000000000008
RBP: 0000000000000000 R08: 94ae31d6fda838a4 R0900007fe8001c9d30
R10: 00007ffdbd1d34b0 R11: 0000000000000246 R12: 00007ffdbd1d3600
R13: 0000000000000000 R14: fffffffffffffffc R15: 00007ffdbd1d3560
</TASK>

Link: https://lkml.kernel.org/r/20220813020509.90805-1-kuniyu@amazon.com
Fixes: 69d54b916d83 ("kprobes: makes kprobes/enabled works correctly for optimized kprobes.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reported-by: Ayushman Dutta <ayudutta@amazon.com>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Kuniyuki Iwashima <kuni1840@gmail.com>
Cc: Ayushman Dutta <ayudutta@amazon.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05 10:25:07 +02:00
Yang Jihong
4c34a2a6c9 ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead
commit c3b0f72e805f0801f05fa2aa52011c4bfc694c44 upstream.

ftrace_startup does not remove ops from ftrace_ops_list when
ftrace_startup_enable fails:

register_ftrace_function
  ftrace_startup
    __register_ftrace_function
      ...
      add_ftrace_ops(&ftrace_ops_list, ops)
      ...
    ...
    ftrace_startup_enable // if ftrace failed to modify, ftrace_disabled is set to 1
    ...
  return 0 // ops is in the ftrace_ops_list.

When ftrace_disabled = 1, unregister_ftrace_function simply returns without doing anything:
unregister_ftrace_function
  ftrace_shutdown
    if (unlikely(ftrace_disabled))
            return -ENODEV;  // return here, __unregister_ftrace_function is not executed,
                             // as a result, ops is still in the ftrace_ops_list
    __unregister_ftrace_function
    ...

If ops is dynamically allocated, it will be free later, in this case,
is_ftrace_trampoline accesses NULL pointer:

is_ftrace_trampoline
  ftrace_ops_trampoline
    do_for_each_ftrace_op(op, ftrace_ops_list) // OOPS! op may be NULL!

Syzkaller reports as follows:
[ 1203.506103] BUG: kernel NULL pointer dereference, address: 000000000000010b
[ 1203.508039] #PF: supervisor read access in kernel mode
[ 1203.508798] #PF: error_code(0x0000) - not-present page
[ 1203.509558] PGD 800000011660b067 P4D 800000011660b067 PUD 130fb8067 PMD 0
[ 1203.510560] Oops: 0000 [#1] SMP KASAN PTI
[ 1203.511189] CPU: 6 PID: 29532 Comm: syz-executor.2 Tainted: G    B   W         5.10.0 #8
[ 1203.512324] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[ 1203.513895] RIP: 0010:is_ftrace_trampoline+0x26/0xb0
[ 1203.514644] Code: ff eb d3 90 41 55 41 54 49 89 fc 55 53 e8 f2 00 fd ff 48 8b 1d 3b 35 5d 03 e8 e6 00 fd ff 48 8d bb 90 00 00 00 e8 2a 81 26 00 <48> 8b ab 90 00 00 00 48 85 ed 74 1d e8 c9 00 fd ff 48 8d bb 98 00
[ 1203.518838] RSP: 0018:ffffc900012cf960 EFLAGS: 00010246
[ 1203.520092] RAX: 0000000000000000 RBX: 000000000000007b RCX: ffffffff8a331866
[ 1203.521469] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000000010b
[ 1203.522583] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8df18b07
[ 1203.523550] R10: fffffbfff1be3160 R11: 0000000000000001 R12: 0000000000478399
[ 1203.524596] R13: 0000000000000000 R14: ffff888145088000 R15: 0000000000000008
[ 1203.525634] FS:  00007f429f5f4700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000
[ 1203.526801] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1203.527626] CR2: 000000000000010b CR3: 0000000170e1e001 CR4: 00000000003706e0
[ 1203.528611] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1203.529605] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Therefore, when ftrace_startup_enable fails, we need to rollback registration
process and remove ops from ftrace_ops_list.

Link: https://lkml.kernel.org/r/20220818032659.56209-1-yangjihong1@huawei.com

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05 10:25:06 +02:00
Gaosheng Cui
4258d55d38 audit: fix potential double free on error path from fsnotify_add_inode_mark
commit ad982c3be4e60c7d39c03f782733503cbd88fd2a upstream.

Audit_alloc_mark() assign pathname to audit_mark->path, on error path
from fsnotify_add_inode_mark(), fsnotify_put_mark will free memory
of audit_mark->path, but the caller of audit_alloc_mark will free
the pathname again, so there will be double free problem.

Fix this by resetting audit_mark->path to NULL pointer on error path
from fsnotify_add_inode_mark().

Cc: stable@vger.kernel.org
Fixes: 7b1293234084d ("fsnotify: Add group pointer in fsnotify_init_mark()")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05 10:25:02 +02:00
Chen Zhongjin
4262b6eb05 kprobes: Forbid probing on trampoline and BPF code areas
[ Upstream commit 28f6c37a2910f565b4f5960df52b2eccae28c891 ]

kernel_text_address() treats ftrace_trampoline, kprobe_insn_slot
and bpf_text_address as valid kprobe addresses - which is not ideal.

These text areas are removable and changeable without any notification
to kprobes, and probing on them can trigger unexpected behavior:

  https://lkml.org/lkml/2022/7/26/1148

Considering that jump_label and static_call text are already
forbiden to probe, kernel_text_address() should be replaced with
core_kernel_text() and is_module_text_address() to check other text
areas which are unsafe to kprobe.

[ mingo: Rewrote the changelog. ]

Fixes: 5b485629ba0d ("kprobes, extable: Identify kprobes trampolines as kernel text area")
Fixes: 74451e66d516 ("bpf: make jited programs visible in traces")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20220801033719.228248-1-chenzhongjin@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25 11:11:26 +02:00
Chen Zhongjin
8036057f8c profiling: fix shift too large makes kernel panic
[ Upstream commit 0fe6ee8f123a4dfb529a5aff07536bb481f34043 ]

2d186afd04d6 ("profiling: fix shift-out-of-bounds bugs") limits shift
value by [0, BITS_PER_LONG -1], which means [0, 63].

However, syzbot found that the max shift value should be the bit number of
(_etext - _stext).  If shift is outside of this, the "buffer_bytes" will
be zero and will cause kzalloc(0).  Then the kernel panics due to
dereferencing the returned pointer 16.

This can be easily reproduced by passing a large number like 60 to enable
profiling and then run readprofile.

LOGS:
 BUG: kernel NULL pointer dereference, address: 0000000000000010
 #PF: supervisor write access in kernel mode
 #PF: error_code(0x0002) - not-present page
 PGD 6148067 P4D 6148067 PUD 6142067 PMD 0
 PREEMPT SMP
 CPU: 4 PID: 184 Comm: readprofile Not tainted 5.18.0+ #162
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
 RIP: 0010:read_profile+0x104/0x220
 RSP: 0018:ffffc900006fbe80 EFLAGS: 00000202
 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
 RDX: ffff888006150000 RSI: 0000000000000001 RDI: ffffffff82aba4a0
 RBP: 000000000188bb60 R08: 0000000000000010 R09: ffff888006151000
 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82aba4a0
 R13: 0000000000000000 R14: ffffc900006fbf08 R15: 0000000000020c30
 FS:  000000000188a8c0(0000) GS:ffff88803ed00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000010 CR3: 0000000006144000 CR4: 00000000000006e0
 Call Trace:
  <TASK>
  proc_reg_read+0x56/0x70
  vfs_read+0x9a/0x1b0
  ksys_read+0xa1/0xe0
  ? fpregs_assert_state_consistent+0x1e/0x40
  do_syscall_64+0x3a/0x80
  entry_SYSCALL_64_after_hwframe+0x46/0xb0
 RIP: 0033:0x4d4b4e
 RSP: 002b:00007ffebb668d58 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
 RAX: ffffffffffffffda RBX: 000000000188a8a0 RCX: 00000000004d4b4e
 RDX: 0000000000000400 RSI: 000000000188bb60 RDI: 0000000000000003
 RBP: 0000000000000003 R08: 000000000000006e R09: 0000000000000000
 R10: 0000000000000041 R11: 0000000000000246 R12: 000000000188bb60
 R13: 0000000000000400 R14: 0000000000000000 R15: 000000000188bb60
  </TASK>
 Modules linked in:
 CR2: 0000000000000010
Killed
 ---[ end trace 0000000000000000 ]---

Check prof_len in profile_init() to prevent it be zero.

Link: https://lkml.kernel.org/r/20220531012854.229439-1-chenzhongjin@huawei.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25 11:11:24 +02:00
Tetsuo Handa
8c90947e5f PM: hibernate: defer device probing when resuming from hibernation
[ Upstream commit 8386c414e27caba8501119948e9551e52b527f59 ]

syzbot is reporting hung task at misc_open() [1], for there is a race
window of AB-BA deadlock which involves probe_count variable. Currently
wait_for_device_probe() from snapshot_open() from misc_open() can sleep
forever with misc_mtx held if probe_count cannot become 0.

When a device is probed by hub_event() work function, probe_count is
incremented before the probe function starts, and probe_count is
decremented after the probe function completed.

There are three cases that can prevent probe_count from dropping to 0.

  (a) A device being probed stopped responding (i.e. broken/malicious
      hardware).

  (b) A process emulating a USB device using /dev/raw-gadget interface
      stopped responding for some reason.

  (c) New device probe requests keeps coming in before existing device
      probe requests complete.

The phenomenon syzbot is reporting is (b). A process which is holding
system_transition_mutex and misc_mtx is waiting for probe_count to become
0 inside wait_for_device_probe(), but the probe function which is called
 from hub_event() work function is waiting for the processes which are
blocked at mutex_lock(&misc_mtx) to respond via /dev/raw-gadget interface.

This patch mitigates (b) by deferring wait_for_device_probe() from
snapshot_open() to snapshot_write() and snapshot_ioctl(). Please note that
the possibility of (b) remains as long as any thread which is emulating a
USB device via /dev/raw-gadget interface can be blocked by uninterruptible
blocking operations (e.g. mutex_lock()).

Please also note that (a) and (c) are not addressed. Regarding (c), we
should change the code to wait for only one device which contains the
image for resuming from hibernation. I don't know how to address (a), for
use of timeout for wait_for_device_probe() might result in loss of user
data in the image. Maybe we should require the userland to wait for the
image device before opening /dev/snapshot interface.

Link: https://syzkaller.appspot.com/bug?extid=358c9ab4c93da7b7238c [1]
Reported-by: syzbot <syzbot+358c9ab4c93da7b7238c@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+358c9ab4c93da7b7238c@syzkaller.appspotmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25 11:11:14 +02:00
Eric Dumazet
875c9839f7 bpf: Make sure mac_header was set before using it
commit 0326195f523a549e0a9d7fd44c70b26fd7265090 upstream.

Classic BPF has a way to load bytes starting from the mac header.

Some skbs do not have a mac header, and skb_mac_header()
in this case is returning a pointer that 65535 bytes after
skb->head.

Existing range check in bpf_internal_load_pointer_neg_helper()
was properly kicking and no illegal access was happening.

New sanity check in skb_mac_header() is firing, so we need
to avoid it.

WARNING: CPU: 1 PID: 28990 at include/linux/skbuff.h:2785 skb_mac_header include/linux/skbuff.h:2785 [inline]
WARNING: CPU: 1 PID: 28990 at include/linux/skbuff.h:2785 bpf_internal_load_pointer_neg_helper+0x1b1/0x1c0 kernel/bpf/core.c:74
Modules linked in:
CPU: 1 PID: 28990 Comm: syz-executor.0 Not tainted 5.19.0-rc4-syzkaller-00865-g4874fb9484be #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
RIP: 0010:skb_mac_header include/linux/skbuff.h:2785 [inline]
RIP: 0010:bpf_internal_load_pointer_neg_helper+0x1b1/0x1c0 kernel/bpf/core.c:74
Code: ff ff 45 31 f6 e9 5a ff ff ff e8 aa 27 40 00 e9 3b ff ff ff e8 90 27 40 00 e9 df fe ff ff e8 86 27 40 00 eb 9e e8 2f 2c f3 ff <0f> 0b eb b1 e8 96 27 40 00 e9 79 fe ff ff 90 41 57 41 56 41 55 41
RSP: 0018:ffffc9000309f668 EFLAGS: 00010216
RAX: 0000000000000118 RBX: ffffffffffeff00c RCX: ffffc9000e417000
RDX: 0000000000040000 RSI: ffffffff81873f21 RDI: 0000000000000003
RBP: ffff8880842878c0 R08: 0000000000000003 R09: 000000000000ffff
R10: 000000000000ffff R11: 0000000000000001 R12: 0000000000000004
R13: ffff88803ac56c00 R14: 000000000000ffff R15: dffffc0000000000
FS: 00007f5c88a16700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdaa9f6c058 CR3: 000000003a82c000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
____bpf_skb_load_helper_32 net/core/filter.c:276 [inline]
bpf_skb_load_helper_32+0x191/0x220 net/core/filter.c:264

Fixes: f9aefd6b2aa3 ("net: warn if mac header was not set")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220707123900.945305-1-edumazet@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-29 17:06:51 +02:00
Peter Zijlstra
f836f9ac95 perf/core: Fix data race between perf_event_set_output() and perf_mmap_close()
[ Upstream commit 68e3c69803dada336893640110cb87221bb01dcf ]

Yang Jihing reported a race between perf_event_set_output() and
perf_mmap_close():

	CPU1					CPU2

	perf_mmap_close(e2)
	  if (atomic_dec_and_test(&e2->rb->mmap_count)) // 1 - > 0
	    detach_rest = true

						ioctl(e1, IOC_SET_OUTPUT, e2)
						  perf_event_set_output(e1, e2)

	  ...
	  list_for_each_entry_rcu(e, &e2->rb->event_list, rb_entry)
	    ring_buffer_attach(e, NULL);
	    // e1 isn't yet added and
	    // therefore not detached

						    ring_buffer_attach(e1, e2->rb)
						      list_add_rcu(&e1->rb_entry,
								   &e2->rb->event_list)

After this; e1 is attached to an unmapped rb and a subsequent
perf_mmap() will loop forever more:

	again:
		mutex_lock(&e->mmap_mutex);
		if (event->rb) {
			...
			if (!atomic_inc_not_zero(&e->rb->mmap_count)) {
				...
				mutex_unlock(&e->mmap_mutex);
				goto again;
			}
		}

The loop in perf_mmap_close() holds e2->mmap_mutex, while the attach
in perf_event_set_output() holds e1->mmap_mutex. As such there is no
serialization to avoid this race.

Change perf_event_set_output() to take both e1->mmap_mutex and
e2->mmap_mutex to alleviate that problem. Additionally, have the loop
in perf_mmap() detach the rb directly, this avoids having to wait for
the concurrent perf_mmap_close() to get around to doing it to make
progress.

Fixes: 9bb5d40cd93c ("perf: Fix mmap() accounting hole")
Reported-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Yang Jihong <yangjihong1@huawei.com>
Link: https://lkml.kernel.org/r/YsQ3jm2GR38SW7uD@worktop.programming.kicks-ass.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-29 17:06:49 +02:00
Linus Torvalds
31d3649b68 signal handling: don't use BUG_ON() for debugging
[ Upstream commit a382f8fee42ca10c9bfce0d2352d4153f931f5dc ]

These are indeed "should not happen" situations, but it turns out recent
changes made the 'task_is_stopped_or_trace()' case trigger (fix for that
exists, is pending more testing), and the BUG_ON() makes it
unnecessarily hard to actually debug for no good reason.

It's been that way for a long time, but let's make it clear: BUG_ON() is
not good for debugging, and should never be used in situations where you
could just say "this shouldn't happen, but we can continue".

Use WARN_ON_ONCE() instead to make sure it gets logged, and then just
continue running.  Instead of making the system basically unusuable
because you crashed the machine while potentially holding some very core
locks (eg this function is commonly called while holding 'tasklist_lock'
for writing).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-21 20:42:47 +02:00
Tejun Heo
05f7658210 cgroup: Use separate src/dst nodes when preloading css_sets for migration
commit 07fd5b6cdf3cc30bfde8fe0f644771688be04447 upstream.

Each cset (css_set) is pinned by its tasks. When we're moving tasks around
across csets for a migration, we need to hold the source and destination
csets to ensure that they don't go away while we're moving tasks about. This
is done by linking cset->mg_preload_node on either the
mgctx->preloaded_src_csets or mgctx->preloaded_dst_csets list. Using the
same cset->mg_preload_node for both the src and dst lists was deemed okay as
a cset can't be both the source and destination at the same time.

Unfortunately, this overloading becomes problematic when multiple tasks are
involved in a migration and some of them are identity noop migrations while
others are actually moving across cgroups. For example, this can happen with
the following sequence on cgroup1:

 #1> mkdir -p /sys/fs/cgroup/misc/a/b
 #2> echo $$ > /sys/fs/cgroup/misc/a/cgroup.procs
 #3> RUN_A_COMMAND_WHICH_CREATES_MULTIPLE_THREADS &
 #4> PID=$!
 #5> echo $PID > /sys/fs/cgroup/misc/a/b/tasks
 #6> echo $PID > /sys/fs/cgroup/misc/a/cgroup.procs

the process including the group leader back into a. In this final migration,
non-leader threads would be doing identity migration while the group leader
is doing an actual one.

After #3, let's say the whole process was in cset A, and that after #4, the
leader moves to cset B. Then, during #6, the following happens:

 1. cgroup_migrate_add_src() is called on B for the leader.

 2. cgroup_migrate_add_src() is called on A for the other threads.

 3. cgroup_migrate_prepare_dst() is called. It scans the src list.

 4. It notices that B wants to migrate to A, so it tries to A to the dst
    list but realizes that its ->mg_preload_node is already busy.

 5. and then it notices A wants to migrate to A as it's an identity
    migration, it culls it by list_del_init()'ing its ->mg_preload_node and
    putting references accordingly.

 6. The rest of migration takes place with B on the src list but nothing on
    the dst list.

This means that A isn't held while migration is in progress. If all tasks
leave A before the migration finishes and the incoming task pins it, the
cset will be destroyed leading to use-after-free.

This is caused by overloading cset->mg_preload_node for both src and dst
preload lists. We wanted to exclude the cset from the src list but ended up
inadvertently excluding it from the dst list too.

This patch fixes the issue by separating out cset->mg_preload_node into
->mg_src_preload_node and ->mg_dst_preload_node, so that the src and dst
preloadings don't interfere with each other.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Mukesh Ojha <quic_mojha@quicinc.com>
Reported-by: shisiyuan <shisiyuan19870131@gmail.com>
Link: http://lkml.kernel.org/r/1654187688-27411-1-git-send-email-shisiyuan@xiaomi.com
Link: https://www.spinics.net/lists/cgroups/msg33313.html
Fixes: f817de98513d ("cgroup: prepare migration path for unified hierarchy")
Cc: stable@vger.kernel.org # v3.16+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-21 20:42:43 +02:00
Naveen N. Rao
6af88cc6e4 kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add]
commit 3e35142ef99fe6b4fe5d834ad43ee13cca10a2dc upstream.

Since commit d1bcae833b32f1 ("ELF: Don't generate unused section
symbols") [1], binutils (v2.36+) started dropping section symbols that
it thought were unused.  This isn't an issue in general, but with
kexec_file.c, gcc is placing kexec_arch_apply_relocations[_add] into a
separate .text.unlikely section and the section symbol ".text.unlikely"
is being dropped. Due to this, recordmcount is unable to find a non-weak
symbol in .text.unlikely to generate a relocation record against.

Address this by dropping the weak attribute from these functions.
Instead, follow the existing pattern of having architectures #define the
name of the function they want to override in their headers.

[1] https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d1bcae833b32f1

[akpm@linux-foundation.org: arch/s390/include/asm/kexec.h needs linux/module.h]
Link: https://lkml.kernel.org/r/20220519091237.676736-1-naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-02 16:18:11 +02:00
Jason A. Donenfeld
2142a4d898 timekeeping: Add raw clock fallback for random_get_entropy()
commit 1366992e16bddd5e2d9a561687f367f9f802e2e4 upstream.

The addition of random_get_entropy_fallback() provides access to
whichever time source has the highest frequency, which is useful for
gathering entropy on platforms without available cycle counters. It's
not necessarily as good as being able to quickly access a cycle counter
that the CPU has, but it's still something, even when it falls back to
being jiffies-based.

In the event that a given arch does not define get_cycles(), falling
back to the get_cycles() default implementation that returns 0 is really
not the best we can do. Instead, at least calling
random_get_entropy_fallback() would be preferable, because that always
needs to return _something_, even falling back to jiffies eventually.
It's not as though random_get_entropy_fallback() is super high precision
or guaranteed to be entropic, but basically anything that's not zero all
the time is better than returning zero all the time.

Finally, since random_get_entropy_fallback() is used during extremely
early boot when randomizing freelists in mm_init(), it can be called
before timekeeping has been initialized. In that case there really is
nothing we can do; jiffies hasn't even started ticking yet. So just give
up and return 0.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25 11:46:38 +02:00
Jason A. Donenfeld
40b5b4b622 random: clear fast pool, crng, and batches in cpuhp bring up
commit 3191dd5a1179ef0fad5a050a1702ae98b6251e8f upstream.

For the irq randomness fast pool, rather than having to use expensive
atomics, which were visibly the most expensive thing in the entire irq
handler, simply take care of the extreme edge case of resetting count to
zero in the cpuhp online handler, just after workqueues have been
reenabled. This simplifies the code a bit and lets us use vanilla
variables rather than atomics, and performance should be improved.

As well, very early on when the CPU comes up, while interrupts are still
disabled, we clear out the per-cpu crng and its batches, so that it
always starts with fresh randomness.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Sultan Alsawaf <sultan@kerneltoast.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25 11:46:35 +02:00
Sebastian Andrzej Siewior
5a0fda8f1b random: remove unused irq_flags argument from add_interrupt_randomness()
commit 703f7066f40599c290babdb79dd61319264987e9 upstream.

Since commit
   ee3e00e9e7101 ("random: use registers from interrupted code for CPU's w/o a cycle counter")

the irq_flags argument is no longer used.

Remove unused irq_flags.

Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: linux-hyperv@vger.kernel.org
Cc: x86@kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-25 11:46:30 +02:00
Mark-PK Tsai
0816ec55fc tracing: Avoid adding tracer option before update_tracer_options
[ Upstream commit ef9188bcc6ca1d8a2ad83e826b548e6820721061 ]

To prepare for support asynchronous tracer_init_tracefs initcall,
avoid calling create_trace_option_files before __update_tracer_options.
Otherwise, create_trace_option_files will show warning because
some tracers in trace_types list are already in tr->topts.

For example, hwlat_tracer call register_tracer in late_initcall,
and global_trace.dir is already created in tracing_init_dentry,
hwlat_tracer will be put into tr->topts.
Then if the __update_tracer_options is executed after hwlat_tracer
registered, create_trace_option_files find that hwlat_tracer is
already in tr->topts.

Link: https://lkml.kernel.org/r/20220426122407.17042-2-mark-pk.tsai@mediatek.com

Link: https://lore.kernel.org/lkml/20220322133339.GA32582@xsang-OptiPlex-9020/
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 16:53:58 +02:00
Jun Miao
be1f323fb9 tracing: Fix sleeping function called from invalid context on RT kernel
[ Upstream commit 12025abdc8539ed9d5014e2d647a3fd1bd3de5cd ]

When setting bootparams="trace_event=initcall:initcall_start tp_printk=1" in the
cmdline, the output_printk() was called, and the spin_lock_irqsave() was called in the
atomic and irq disable interrupt context suitation. On the PREEMPT_RT kernel,
these locks are replaced with sleepable rt-spinlock, so the stack calltrace will
be triggered.
Fix it by raw_spin_lock_irqsave when PREEMPT_RT and "trace_event=initcall:initcall_start
tp_printk=1" enabled.

 BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46
 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0
 preempt_count: 2, expected: 0
 RCU nest depth: 0, expected: 0
 Preemption disabled at:
 [<ffffffff8992303e>] try_to_wake_up+0x7e/0xba0
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.1-rt17+ #19 34c5812404187a875f32bee7977f7367f9679ea7
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
 Call Trace:
  <TASK>
  dump_stack_lvl+0x60/0x8c
  dump_stack+0x10/0x12
  __might_resched.cold+0x11d/0x155
  rt_spin_lock+0x40/0x70
  trace_event_buffer_commit+0x2fa/0x4c0
  ? map_vsyscall+0x93/0x93
  trace_event_raw_event_initcall_start+0xbe/0x110
  ? perf_trace_initcall_finish+0x210/0x210
  ? probe_sched_wakeup+0x34/0x40
  ? ttwu_do_wakeup+0xda/0x310
  ? trace_hardirqs_on+0x35/0x170
  ? map_vsyscall+0x93/0x93
  do_one_initcall+0x217/0x3c0
  ? trace_event_raw_event_initcall_level+0x170/0x170
  ? push_cpu_stop+0x400/0x400
  ? cblist_init_generic+0x241/0x290
  kernel_init_freeable+0x1ac/0x347
  ? _raw_spin_unlock_irq+0x65/0x80
  ? rest_init+0xf0/0xf0
  kernel_init+0x1e/0x150
  ret_from_fork+0x22/0x30
  </TASK>

Link: https://lkml.kernel.org/r/20220419013910.894370-1-jun.miao@intel.com

Signed-off-by: Jun Miao <jun.miao@intel.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 16:53:57 +02:00
Eric W. Biederman
b5a53485dd ptrace: Reimplement PTRACE_KILL by always sending SIGKILL
commit 6a2d90ba027adba528509ffa27097cffd3879257 upstream.

The current implementation of PTRACE_KILL is buggy and has been for
many years as it assumes it's target has stopped in ptrace_stop.  At a
quick skim it looks like this assumption has existed since ptrace
support was added in linux v1.0.

While PTRACE_KILL has been deprecated we can not remove it as
a quick search with google code search reveals many existing
programs calling it.

When the ptracee is not stopped at ptrace_stop some fields would be
set that are ignored except in ptrace_stop.  Making the userspace
visible behavior of PTRACE_KILL a noop in those case.

As the usual rules are not obeyed it is not clear what the
consequences are of calling PTRACE_KILL on a running process.
Presumably userspace does not do this as it achieves nothing.

Replace the implementation of PTRACE_KILL with a simple
send_sig_info(SIGKILL) followed by a return 0.  This changes the
observable user space behavior only in that PTRACE_KILL on a process
not stopped in ptrace_stop will also kill it.  As that has always
been the intent of the code this seems like a reasonable change.

Cc: stable@vger.kernel.org
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20220505182645.497868-7-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14 16:53:43 +02:00
Peter Zijlstra
dee63319e2 perf: Fix sys_perf_event_open() race against self
commit 3ac6487e584a1eb54071dbe1212e05b884136704 upstream.

Norbert reported that it's possible to race sys_perf_event_open() such
that the looser ends up in another context from the group leader,
triggering many WARNs.

The move_group case checks for races against itself, but the
!move_group case doesn't, seemingly relying on the previous
group_leader->ctx == ctx check. However, that check is racy due to not
holding any locks at that time.

Therefore, re-check the result after acquiring locks and bailing
if they no longer match.

Additionally, clarify the not_move_group case from the
move_group-vs-move_group race.

Fixes: f63a8daa5812 ("perf: Fix event->ctx locking")
Reported-by: Norbert Slusarek <nslusarek@gmx.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-25 08:41:19 +02:00
Waiman Long
7a34036ee5 cgroup/cpuset: Remove cpus_allowed/mems_allowed setup in cpuset_init_smp()
commit 2685027fca387b602ae565bff17895188b803988 upstream.

There are 3 places where the cpu and node masks of the top cpuset can
be initialized in the order they are executed:
 1) start_kernel -> cpuset_init()
 2) start_kernel -> cgroup_init() -> cpuset_bind()
 3) kernel_init_freeable() -> do_basic_setup() -> cpuset_init_smp()

The first cpuset_init() call just sets all the bits in the masks.
The second cpuset_bind() call sets cpus_allowed and mems_allowed to the
default v2 values. The third cpuset_init_smp() call sets them back to
v1 values.

For systems with cgroup v2 setup, cpuset_bind() is called once.  As a
result, cpu and memory node hot add may fail to update the cpu and node
masks of the top cpuset to include the newly added cpu or node in a
cgroup v2 environment.

For systems with cgroup v1 setup, cpuset_bind() is called again by
rebind_subsystem() when the v1 cpuset filesystem is mounted as shown
in the dmesg log below with an instrumented kernel.

  [    2.609781] cpuset_bind() called - v2 = 1
  [    3.079473] cpuset_init_smp() called
  [    7.103710] cpuset_bind() called - v2 = 0

smp_init() is called after the first two init functions.  So we don't
have a complete list of active cpus and memory nodes until later in
cpuset_init_smp() which is the right time to set up effective_cpus
and effective_mems.

To fix this cgroup v2 mask setup problem, the potentially incorrect
cpus_allowed & mems_allowed setting in cpuset_init_smp() are removed.
For cgroup v2 systems, the initial cpuset_bind() call will set the masks
correctly.  For cgroup v1 systems, the second call to cpuset_bind()
will do the right setup.

cc: stable@vger.kernel.org
Signed-off-by: Waiman Long <longman@redhat.com>
Tested-by: Feng Tang <feng.tang@intel.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-18 09:18:08 +02:00
Daniel Bristot de Oliveira
b45bda0c85 tracing: Dump stacktrace trigger to the corresponding instance
commit ce33c845b030c9cf768370c951bc699470b09fa7 upstream.

The stacktrace event trigger is not dumping the stacktrace to the instance
where it was enabled, but to the global "instance."

Use the private_data, pointing to the trigger file, to figure out the
corresponding trace instance, and use it in the trigger action, like
snapshot_trigger does.

Link: https://lkml.kernel.org/r/afbb0b4f18ba92c276865bc97204d438473f4ebc.1645396236.git.bristot@kernel.org

Cc: stable@vger.kernel.org
Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-27 13:15:29 +02:00
Steven Rostedt (Google)
34a11aff55 tracing: Have traceon and traceoff trigger honor the instance
commit 302e9edd54985f584cfc180098f3554774126969 upstream.

If a trigger is set on an event to disable or enable tracing within an
instance, then tracing should be disabled or enabled in the instance and
not at the top level, which is confusing to users.

Link: https://lkml.kernel.org/r/20220223223837.14f94ec3@rorschach.local.home

Cc: stable@vger.kernel.org
Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables")
Tested-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-27 13:15:29 +02:00
Nadav Amit
0f088623b6 smp: Fix offline cpu check in flush_smp_call_function_queue()
commit 9e949a3886356fe9112c6f6f34a6e23d1d35407f upstream.

The check in flush_smp_call_function_queue() for callbacks that are sent
to offline CPUs currently checks whether the queue is empty.

However, flush_smp_call_function_queue() has just deleted all the
callbacks from the queue and moved all the entries into a local list.
This checks would only be positive if some callbacks were added in the
short time after llist_del_all() was called. This does not seem to be
the intention of this check.

Change the check to look at the local list to which the entries were
moved instead of the queue from which all the callbacks were just
removed.

Fixes: 8d056c48e4862 ("CPU hotplug, smp: flush any pending IPI callbacks before CPU offline")
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220319072015.1495036-1-namit@vmware.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-20 09:08:33 +02:00
Tejun Heo
2337c8257c cgroup: Use open-time cgroup namespace for process migration perm checks
commit e57457641613fef0d147ede8bd6a3047df588b95 upstream.

cgroup process migration permission checks are performed at write time as
whether a given operation is allowed or not is dependent on the content of
the write - the PID. This currently uses current's cgroup namespace which is
a potential security weakness as it may allow scenarios where a less
privileged process tricks a more privileged one into writing into a fd that
it created.

This patch makes cgroup remember the cgroup namespace at the time of open
and uses it for migration permission checks instad of current's. Note that
this only applies to cgroup2 as cgroup1 doesn't have namespace support.

This also fixes a use-after-free bug on cgroupns reported in

 https://lore.kernel.org/r/00000000000048c15c05d0083397@google.com

Note that backporting this fix also requires the preceding patch.

Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Reported-by: syzbot+50f5cf33a284ce738b62@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/00000000000048c15c05d0083397@google.com
Fixes: 5136f6365ce3 ("cgroup: implement "nsdelegate" mount option")
Signed-off-by: Tejun Heo <tj@kernel.org>
[mkoutny: v5.10: duplicate ns check in procs/threads write handler, adjust context]
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[OP: backport to v4.14: drop changes to cgroup_attach_permissions() and
cgroup_css_set_fork(), adjust cgroup_procs_write_permission() calls]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-20 09:08:30 +02:00
Tejun Heo
f1ce7855af cgroup: Allocate cgroup_file_ctx for kernfs_open_file->priv
commit 0d2b5955b36250a9428c832664f2079cbf723bec upstream.

of->priv is currently used by each interface file implementation to store
private information. This patch collects the current two private data usages
into struct cgroup_file_ctx which is allocated and freed by the common path.
This allows generic private data which applies to multiple files, which will
be used to in the following patch.

Note that cgroup_procs iterator is now embedded as procs.iter in the new
cgroup_file_ctx so that it doesn't need to be allocated and freed
separately.

v2: union dropped from cgroup_file_ctx and the procs iterator is embedded in
    cgroup_file_ctx as suggested by Linus.

v3: Michal pointed out that cgroup1's procs pidlist uses of->priv too.
    Converted. Didn't change to embedded allocation as cgroup1 pidlists get
    stored for caching.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
[mkoutny: v5.10: modify cgroup.pressure handlers, adjust context]
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[OP: backport to v4.14: drop changes to cgroup_pressure_*() functions]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-20 09:08:30 +02:00
Tejun Heo
a70bcf9ed0 cgroup: Use open-time credentials for process migraton perm checks
commit 1756d7994ad85c2479af6ae5a9750b92324685af upstream.

cgroup process migration permission checks are performed at write time as
whether a given operation is allowed or not is dependent on the content of
the write - the PID. This currently uses current's credentials which is a
potential security weakness as it may allow scenarios where a less
privileged process tricks a more privileged one into writing into a fd that
it created.

This patch makes both cgroup2 and cgroup1 process migration interfaces to
use the credentials saved at the time of open (file->f_cred) instead of
current's.

Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Fixes: 187fe84067bd ("cgroup: require write perm on common ancestor when moving processes on the default hierarchy")
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
[OP: backport to v4.14: apply original __cgroup_procs_write() changes to
cgroup_threads_write() and cgroup_procs_write()]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-20 09:08:30 +02:00
Randy Dunlap
74de43caff printk: fix return value of printk.devkmsg __setup handler
[ Upstream commit b665eae7a788c5e2bc10f9ac3c0137aa0ad1fc97 ]

If an invalid option value is used with "printk.devkmsg=<value>",
it is silently ignored.
If a valid option value is used, it is honored but the wrong return
value (0) is used, indicating that the command line option had an
error and was not handled. This string is not added to init's
environment strings due to init/main.c::unknown_bootoption()
checking for a '.' in the boot option string and then considering
that string to be an "Unused module parameter".

Print a warning message if a bad option string is used.
Always return 1 from the __setup handler to indicate that the command
line option has been handled.

Fixes: 750afe7babd1 ("printk: add kernel parameter to control writes to /dev/kmsg")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Cc: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: John Ogness <john.ogness@linutronix.de>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220228220556.23484-1-rdunlap@infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20 09:08:15 +02:00
Adrian Hunter
1b306bed30 perf/core: Fix address filter parser for multiple filters
[ Upstream commit d680ff24e9e14444c63945b43a37ede7cd6958f9 ]

Reset appropriate variables in the parser loop between parsing separate
filters, so that they do not interfere with parsing the next filter.

Fixes: 375637bc524952 ("perf/core: Introduce address range filtering")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220131072453.2839535-4-adrian.hunter@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20 09:08:14 +02:00
Bharata B Rao
55dc09d495 sched/debug: Remove mpol_get/put and task_lock/unlock from sched_show_numa
[ Upstream commit 28c988c3ec29db74a1dda631b18785958d57df4f ]

The older format of /proc/pid/sched printed home node info which
required the mempolicy and task lock around mpol_get(). However
the format has changed since then and there is no need for
sched_show_numa() any more to have mempolicy argument,
asssociated mpol_get/put and task_lock/unlock. Remove them.

Fixes: 397f2378f1361 ("sched/numa: Fix numa balancing stats in /proc/pid/sched")
Signed-off-by: Bharata B Rao <bharata@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Link: https://lore.kernel.org/r/20220118050515.2973-1-bharata@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20 09:08:13 +02:00