52211 Commits

Author SHA1 Message Date
Andreas Gruenbacher
4d6df332cf nfs: Fix potential posix_acl refcnt leak in nfs3_set_acl
commit 7648f939cb919b9d15c21fff8cd9eba908d595dc upstream.

nfs3_set_acl keeps track of the acl it allocated locally to determine if an acl
needs to be released at the end.  This results in a memory leak when the
function allocates an acl as well as a default acl.  Fix by releasing acls
that differ from the acl originally passed into nfs3_set_acl.

Fixes: b7fa0554cf1b ("[PATCH] NFS: Add support for NFSv3 ACLs")
Reported-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-05 19:15:52 +02:00
Filipe Manana
3aaee8e2fe btrfs: fix partial loss of prealloc extent past i_size after fsync
commit f135cea30de5f74d5bfb5116682073841fb4af8f upstream.

When we have an inode with a prealloc extent that starts at an offset
lower than the i_size and there is another prealloc extent that starts at
an offset beyond i_size, we can end up losing part of the first prealloc
extent (the part that starts at i_size) and have an implicit hole if we
fsync the file and then have a power failure.

Consider the following example with comments explaining how and why it
happens.

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  # Create our test file with 2 consecutive prealloc extents, each with a
  # size of 128Kb, and covering the range from 0 to 256Kb, with a file
  # size of 0.
  $ xfs_io -f -c "falloc -k 0 128K" /mnt/foo
  $ xfs_io -c "falloc -k 128K 128K" /mnt/foo

  # Fsync the file to record both extents in the log tree.
  $ xfs_io -c "fsync" /mnt/foo

  # Now do a redudant extent allocation for the range from 0 to 64Kb.
  # This will merely increase the file size from 0 to 64Kb. Instead we
  # could also do a truncate to set the file size to 64Kb.
  $ xfs_io -c "falloc 0 64K" /mnt/foo

  # Fsync the file, so we update the inode item in the log tree with the
  # new file size (64Kb). This also ends up setting the number of bytes
  # for the first prealloc extent to 64Kb. This is done by the truncation
  # at btrfs_log_prealloc_extents().
  # This means that if a power failure happens after this, a write into
  # the file range 64Kb to 128Kb will not use the prealloc extent and
  # will result in allocation of a new extent.
  $ xfs_io -c "fsync" /mnt/foo

  # Now set the file size to 256K with a truncate and then fsync the file.
  # Since no changes happened to the extents, the fsync only updates the
  # i_size in the inode item at the log tree. This results in an implicit
  # hole for the file range from 64Kb to 128Kb, something which fsck will
  # complain when not using the NO_HOLES feature if we replay the log
  # after a power failure.
  $ xfs_io -c "truncate 256K" -c "fsync" /mnt/foo

So instead of always truncating the log to the inode's current i_size at
btrfs_log_prealloc_extents(), check first if there's a prealloc extent
that starts at an offset lower than the i_size and with a length that
crosses the i_size - if there is one, just make sure we truncate to a
size that corresponds to the end offset of that prealloc extent, so
that we don't lose the part of that extent that starts at i_size if a
power failure happens.

A test case for fstests follows soon.

Fixes: 31d11b83b96f ("Btrfs: fix duplicate extents after fsync of file with prealloc extents")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-05 19:15:49 +02:00
Xiyu Yang
4f7ade4152 btrfs: fix block group leak when removing fails
commit f6033c5e333238f299c3ae03fac8cc1365b23b77 upstream.

btrfs_remove_block_group() invokes btrfs_lookup_block_group(), which
returns a local reference of the block group that contains the given
bytenr to "block_group" with increased refcount.

When btrfs_remove_block_group() returns, "block_group" becomes invalid,
so the refcount should be decreased to keep refcount balanced.

The reference counting issue happens in several exception handling paths
of btrfs_remove_block_group(). When those error scenarios occur such as
btrfs_alloc_path() returns NULL, the function forgets to decrease its
refcnt increased by btrfs_lookup_block_group() and will cause a refcnt
leak.

Fix this issue by jumping to "out_put_group" label and calling
btrfs_put_block_group() when those error scenarios occur.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-05 19:15:48 +02:00
Theodore Ts'o
b4586e02a3 ext4: fix special inode number checks in __ext4_iget()
commit 191ce17876c9367819c4b0a25b503c0f6d9054d8 upstream.

The check for special (reserved) inode number checks in __ext4_iget()
was broken by commit 8a363970d1dc: ("ext4: avoid declaring fs
inconsistent due to invalid file handles").  This was caused by a
botched reversal of the sense of the flag now known as
EXT4_IGET_SPECIAL (when it was previously named EXT4_IGET_NORMAL).
Fix the logic appropriately.

Fixes: 8a363970d1dc ("ext4: avoid declaring fs inconsistent...")
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@kernel.org
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-05 19:15:47 +02:00
Al Viro
97699864e3 propagate_one(): mnt_set_mountpoint() needs mount_lock
commit b0d3869ce9eeacbb1bbd541909beeef4126426d5 upstream.

... to protect the modification of mp->m_count done by it.  Most of
the places that modify that thing also have namespace_lock held,
but not all of them can do so, so we really need mount_lock here.
Kudos to Piotr Krysiuk <piotras@gmail.com>, who'd spotted a related
bug in pivot_root(2) (fixed unnoticed in 5.3); search for other
similar turds has caught out this one.

Cc: stable@kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:24:47 +02:00
Ritesh Harjani
c65024b376 ext4: check for non-zero journal inum in ext4_calculate_overhead
commit f1eec3b0d0a849996ebee733b053efa71803dad5 upstream.

While calculating overhead for internal journal, also check
that j_inum shouldn't be 0. Otherwise we get below error with
xfstests generic/050 with external journal (XXX_LOGDEV config) enabled.

It could be simply reproduced with loop device with an external journal
and marking blockdev as RO before mounting.

[ 3337.146838] EXT4-fs error (device pmem1p2): ext4_get_journal_inode:4634: comm mount: inode #0: comm mount: iget: illegal inode #
------------[ cut here ]------------
generic_make_request: Trying to write to read-only block-device pmem1p2 (partno 2)
WARNING: CPU: 107 PID: 115347 at block/blk-core.c:788 generic_make_request_checks+0x6b4/0x7d0
CPU: 107 PID: 115347 Comm: mount Tainted: G             L   --------- -t - 4.18.0-167.el8.ppc64le #1
NIP:  c0000000006f6d44 LR: c0000000006f6d40 CTR: 0000000030041dd4
<...>
NIP [c0000000006f6d44] generic_make_request_checks+0x6b4/0x7d0
LR [c0000000006f6d40] generic_make_request_checks+0x6b0/0x7d0
<...>
Call Trace:
generic_make_request_checks+0x6b0/0x7d0 (unreliable)
generic_make_request+0x3c/0x420
submit_bio+0xd8/0x200
submit_bh_wbc+0x1e8/0x250
__sync_dirty_buffer+0xd0/0x210
ext4_commit_super+0x310/0x420 [ext4]
__ext4_error+0xa4/0x1e0 [ext4]
__ext4_iget+0x388/0xe10 [ext4]
ext4_get_journal_inode+0x40/0x150 [ext4]
ext4_calculate_overhead+0x5a8/0x610 [ext4]
ext4_fill_super+0x3188/0x3260 [ext4]
mount_bdev+0x778/0x8f0
ext4_mount+0x28/0x50 [ext4]
mount_fs+0x74/0x230
vfs_kern_mount.part.6+0x6c/0x250
do_mount+0x2fc/0x1280
sys_mount+0x158/0x180
system_call+0x5c/0x70
EXT4-fs (pmem1p2): no journal found
EXT4-fs (pmem1p2): can't get journal size
EXT4-fs (pmem1p2): mounted filesystem without journal. Opts: dax,norecovery

Fixes: 3c816ded78bb ("ext4: use journal inode to determine journal overhead")
Reported-by: Harish Sriram <harish@linux.ibm.com>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200316093038.25485-1-riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:24:46 +02:00
Colin Ian King
22dec5f46b ext4: unsigned int compared against zero
commit fbbbbd2f28aec991f3fbc248df211550fbdfd58c upstream.

There are two cases where u32 variables n and err are being checked
for less than zero error values, the checks is always false because
the variables are not signed. Fix this by making the variables ints.

Addresses-Coverity: ("Unsigned compared against 0")
Fixes: 345c0dbf3a30 ("ext4: protect journal inode's blocks using block_validity")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Ashwin H <ashwinh@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:24:46 +02:00
Theodore Ts'o
ea8f7a3dfd ext4: fix block validity checks for journal inodes using indirect blocks
commit 170417c8c7bb2cbbdd949bf5c443c0c8f24a203b upstream.

Commit 345c0dbf3a30 ("ext4: protect journal inode's blocks using
block_validity") failed to add an exception for the journal inode in
ext4_check_blockref(), which is the function used by ext4_get_branch()
for indirect blocks.  This caused attempts to read from the ext3-style
journals to fail with:

[  848.968550] EXT4-fs error (device sdb7): ext4_get_branch:171: inode #8: block 30343695: comm jbd2/sdb7-8: invalid block

Fix this by adding the missing exception check.

Fixes: 345c0dbf3a30 ("ext4: protect journal inode's blocks using block_validity")
Reported-by: Arthur Marsh <arthur.marsh@internode.on.net>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Ashwin H <ashwinh@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:24:46 +02:00
Theodore Ts'o
fc3293a80a ext4: don't perform block validity checks on the journal inode
commit 0a944e8a6c66ca04c7afbaa17e22bf208a8b37f0 upstream.

Since the journal inode is already checked when we added it to the
block validity's system zone, if we check it again, we'll just trigger
a failure.

This was causing failures like this:

[   53.897001] EXT4-fs error (device sda): ext4_find_extent:909: inode
#8: comm jbd2/sda-8: pblk 121667583 bad header/extent: invalid extent entries - magic f30a, entries 8, max 340(340), depth 0(0)
[   53.931430] jbd2_journal_bmap: journal block not found at offset 49 on sda-8
[   53.938480] Aborting journal on device sda-8.

... but only if the system was under enough memory pressure that
logical->physical mapping for the journal inode gets pushed out of the
extent cache.  (This is why it wasn't noticed earlier.)

Fixes: 345c0dbf3a30 ("ext4: protect journal inode's blocks using block_validity")
Reported-by: Dan Rue <dan.rue@linaro.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Ashwin H <ashwinh@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:24:45 +02:00
Theodore Ts'o
7957624681 ext4: protect journal inode's blocks using block_validity
commit 345c0dbf3a30872d9b204db96b5857cd00808cae upstream.

Add the blocks which belong to the journal inode to block_validity's
system zone so attempts to deallocate or overwrite the journal due a
corrupted file system where the journal blocks are also claimed by
another inode.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202879
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Ashwin H <ashwinh@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:24:45 +02:00
Theodore Ts'o
add40f8f1a ext4: avoid declaring fs inconsistent due to invalid file handles
commit 8a363970d1dc38c4ec4ad575c862f776f468d057 upstream.

If we receive a file handle, either from NFS or open_by_handle_at(2),
and it points at an inode which has not been initialized, and the file
system has metadata checksums enabled, we shouldn't try to get the
inode, discover the checksum is invalid, and then declare the file
system as being inconsistent.

This can be reproduced by creating a test file system via "mke2fs -t
ext4 -O metadata_csum /tmp/foo.img 8M", mounting it, cd'ing into that
directory, and then running the following program.

#define _GNU_SOURCE
#include <fcntl.h>

struct handle {
	struct file_handle fh;
	unsigned char fid[MAX_HANDLE_SZ];
};

int main(int argc, char **argv)
{
	struct handle h = {{8, 1 }, { 12, }};

	open_by_handle_at(AT_FDCWD, &h.fh, O_RDONLY);
	return 0;
}

Google-Bug-Id: 120690101
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Ashwin H <ashwinh@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:24:45 +02:00
Theodore Ts'o
019abc55c9 ext4: convert BUG_ON's to WARN_ON's in mballoc.c
[ Upstream commit 907ea529fc4c3296701d2bfc8b831dd2a8121a34 ]

If the in-core buddy bitmap gets corrupted (or out of sync with the
block bitmap), issue a WARN_ON and try to recover.  In most cases this
involves skipping trying to allocate out of a particular block group.
We can end up declaring the file system corrupted, which is fair,
since the file system probably should be checked before we proceed any
further.

Link: https://lore.kernel.org/r/20200414035649.293164-1-tytso@mit.edu
Google-Bug-Id: 34811296
Google-Bug-Id: 34639169
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-02 17:24:45 +02:00
Theodore Ts'o
48eecff398 ext4: increase wait time needed before reuse of deleted inode numbers
[ Upstream commit a17a9d935dc4a50acefaf319d58030f1da7f115a ]

Current wait times have proven to be too short to protect against inode
reuses that lead to metadata inconsistencies.

Now that we will retry the inode allocation if we can't find any
recently deleted inodes, it's a lot safer to increase the recently
deleted time from 5 seconds to a minute.

Link: https://lore.kernel.org/r/20200414023925.273867-1-tytso@mit.edu
Google-Bug-Id: 36602237
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-02 17:24:44 +02:00
yangerkun
1e68f07c8d ext4: use matching invalidatepage in ext4_writepage
[ Upstream commit c2a559bc0e7ed5a715ad6b947025b33cb7c05ea7 ]

Run generic/388 with journal data mode sometimes may trigger the warning
in ext4_invalidatepage. Actually, we should use the matching invalidatepage
in ext4_writepage.

Signed-off-by: yangerkun <yangerkun@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200226041002.13914-1-yangerkun@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-02 17:24:44 +02:00
Darrick J. Wong
27b8978b06 xfs: fix partially uninitialized structure in xfs_reflink_remap_extent
[ Upstream commit c142932c29e533ee892f87b44d8abc5719edceec ]

In the reflink extent remap function, it turns out that uirec (the block
mapping corresponding only to the part of the passed-in mapping that got
unmapped) was not fully initialized.  Specifically, br_state was not
being copied from the passed-in struct to the uirec.  This could lead to
unpredictable results such as the reflinked mapping being marked
unwritten in the destination file.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-02 17:24:43 +02:00
Vasily Averin
ea0f3c4ef7 nfsd: memory corruption in nfsd4_lock()
commit e1e8399eee72e9d5246d4d1bcacd793debe34dd3 upstream.

New struct nfsd4_blocked_lock allocated in find_or_allocate_block()
does not initialized nbl_list and nbl_lru.
If conflock allocation fails rollback can call list_del_init()
access uninitialized fields and corrupt memory.

v2: just initialize nbl_list and nbl_lru right after nbl allocation.

Fixes: 76d348fadff5 ("nfsd: have nfsd4_lock use blocking locks for v4.1+ lock")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:24:41 +02:00
kaixuxia
f970d41d54 xfs: Fix deadlock between AGI and AGF with RENAME_WHITEOUT
commit bc56ad8c74b8588685c2875de0df8ab6974828ef upstream.

When performing rename operation with RENAME_WHITEOUT flag, we will
hold AGF lock to allocate or free extents in manipulating the dirents
firstly, and then doing the xfs_iunlink_remove() call last to hold
AGI lock to modify the tmpfile info, so we the lock order AGI->AGF.

The big problem here is that we have an ordering constraint on AGF
and AGI locking - inode allocation locks the AGI, then can allocate
a new extent for new inodes, locking the AGF after the AGI. Hence
the ordering that is imposed by other parts of the code is AGI before
AGF. So we get an ABBA deadlock between the AGI and AGF here.

Process A:
Call trace:
 ? __schedule+0x2bd/0x620
 schedule+0x33/0x90
 schedule_timeout+0x17d/0x290
 __down_common+0xef/0x125
 ? xfs_buf_find+0x215/0x6c0 [xfs]
 down+0x3b/0x50
 xfs_buf_lock+0x34/0xf0 [xfs]
 xfs_buf_find+0x215/0x6c0 [xfs]
 xfs_buf_get_map+0x37/0x230 [xfs]
 xfs_buf_read_map+0x29/0x190 [xfs]
 xfs_trans_read_buf_map+0x13d/0x520 [xfs]
 xfs_read_agf+0xa6/0x180 [xfs]
 ? schedule_timeout+0x17d/0x290
 xfs_alloc_read_agf+0x52/0x1f0 [xfs]
 xfs_alloc_fix_freelist+0x432/0x590 [xfs]
 ? down+0x3b/0x50
 ? xfs_buf_lock+0x34/0xf0 [xfs]
 ? xfs_buf_find+0x215/0x6c0 [xfs]
 xfs_alloc_vextent+0x301/0x6c0 [xfs]
 xfs_ialloc_ag_alloc+0x182/0x700 [xfs]
 ? _xfs_trans_bjoin+0x72/0xf0 [xfs]
 xfs_dialloc+0x116/0x290 [xfs]
 xfs_ialloc+0x6d/0x5e0 [xfs]
 ? xfs_log_reserve+0x165/0x280 [xfs]
 xfs_dir_ialloc+0x8c/0x240 [xfs]
 xfs_create+0x35a/0x610 [xfs]
 xfs_generic_create+0x1f1/0x2f0 [xfs]
 ...

Process B:
Call trace:
 ? __schedule+0x2bd/0x620
 ? xfs_bmapi_allocate+0x245/0x380 [xfs]
 schedule+0x33/0x90
 schedule_timeout+0x17d/0x290
 ? xfs_buf_find+0x1fd/0x6c0 [xfs]
 __down_common+0xef/0x125
 ? xfs_buf_get_map+0x37/0x230 [xfs]
 ? xfs_buf_find+0x215/0x6c0 [xfs]
 down+0x3b/0x50
 xfs_buf_lock+0x34/0xf0 [xfs]
 xfs_buf_find+0x215/0x6c0 [xfs]
 xfs_buf_get_map+0x37/0x230 [xfs]
 xfs_buf_read_map+0x29/0x190 [xfs]
 xfs_trans_read_buf_map+0x13d/0x520 [xfs]
 xfs_read_agi+0xa8/0x160 [xfs]
 xfs_iunlink_remove+0x6f/0x2a0 [xfs]
 ? current_time+0x46/0x80
 ? xfs_trans_ichgtime+0x39/0xb0 [xfs]
 xfs_rename+0x57a/0xae0 [xfs]
 xfs_vn_rename+0xe4/0x150 [xfs]
 ...

In this patch we move the xfs_iunlink_remove() call to
before acquiring the AGF lock to preserve correct AGI/AGF locking
order.

[Minor massage required to backport to apply due to removal of
out_bmap_cancel: error path label upstream as a result of code
rework. Only change was to the last code block removed by the
patch. Functionally equivalent to upstream.]

Signed-off-by: kaixuxia <kaixuxia@tencent.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Suraj Jitindar Singh <surajjs@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:24:38 +02:00
Darrick J. Wong
a63c07ef00 xfs: validate sb_logsunit is a multiple of the fs blocksize
commit 9c92ee208b1faa0ef2cc899b85fd0607b6fac7fe upstream.

Make sure the log stripe unit is sane before proceeding with mounting.
AFAICT this means that logsunit has to be 0, 1, or a multiple of the fs
block size.  Found this by setting the LSB of logsunit in xfs/350 and
watching the system crash as soon as we try to write to the log.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Suraj Jitindar Singh <surajjs@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:24:38 +02:00
Jann Horn
e5de393402 vmalloc: fix remap_vmalloc_range() bounds checks
commit bdebd6a2831b6fab69eb85cee74a8ba77f1a1cc2 upstream.

remap_vmalloc_range() has had various issues with the bounds checks it
promises to perform ("This function checks that addr is a valid
vmalloc'ed area, and that it is big enough to cover the vma") over time,
e.g.:

 - not detecting pgoff<<PAGE_SHIFT overflow

 - not detecting (pgoff<<PAGE_SHIFT)+usize overflow

 - not checking whether addr and addr+(pgoff<<PAGE_SHIFT) are the same
   vmalloc allocation

 - comparing a potentially wildly out-of-bounds pointer with the end of
   the vmalloc region

In particular, since commit fc9702273e2e ("bpf: Add mmap() support for
BPF_MAP_TYPE_ARRAY"), unprivileged users can cause kernel null pointer
dereferences by calling mmap() on a BPF map with a size that is bigger
than the distance from the start of the BPF map to the end of the
address space.

This could theoretically be used as a kernel ASLR bypass, by using
whether mmap() with a given offset oopses or returns an error code to
perform a binary search over the possible address range.

To allow remap_vmalloc_range_partial() to verify that addr and
addr+(pgoff<<PAGE_SHIFT) are in the same vmalloc region, pass the offset
to remap_vmalloc_range_partial() instead of adding it to the pointer in
remap_vmalloc_range().

In remap_vmalloc_range_partial(), fix the check against
get_vm_area_size() by using size comparisons instead of pointer
comparisons, and add checks for pgoff.

Fixes: 833423143c3a ("[PATCH] mm: introduce remap_vmalloc_range()")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@chromium.org>
Link: http://lkml.kernel.org/r/20200415222312.236431-1-jannh@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:24:21 +02:00
Piotr Krysiuk
e21c8c03af fs/namespace.c: fix mountpoint reference counter race
A race condition between threads updating mountpoint reference counter
affects longterm releases 4.4.220, 4.9.220, 4.14.177 and 4.19.118.

The mountpoint reference counter corruption may occur when:
* one thread increments m_count member of struct mountpoint
  [under namespace_sem, but not holding mount_lock]
    pivot_root()
* another thread simultaneously decrements the same m_count
  [under mount_lock, but not holding namespace_sem]
    put_mountpoint()
      unhash_mnt()
        umount_mnt()
          mntput_no_expire()

To fix this race condition, grab mount_lock before updating m_count in
pivot_root().

Reference: CVE-2020-12114
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:24:20 +02:00
Yan, Zheng
968b1dd03e ceph: don't skip updating wanted caps when cap is stale
[ Upstream commit 0aa971b6fd3f92afef6afe24ef78d9bb14471519 ]

1. try_get_cap_refs() fails to get caps and finds that mds_wanted
   does not include what it wants. It returns -ESTALE.
2. ceph_get_caps() calls ceph_renew_caps(). ceph_renew_caps() finds
   that inode has cap, so it calls ceph_check_caps().
3. ceph_check_caps() finds that issued caps (without checking if it's
   stale) already includes caps wanted by open file, so it skips
   updating wanted caps.

Above events can cause an infinite loop inside ceph_get_caps().

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-02 17:24:13 +02:00
Qiujun Huang
7435d3c34b ceph: return ceph_mdsc_do_request() errors from __get_parent()
[ Upstream commit c6d50296032f0b97473eb2e274dc7cc5d0173847 ]

Return the error returned by ceph_mdsc_do_request(). Otherwise,
r_target_inode ends up being NULL this ends up returning ENOENT
regardless of the error.

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-02 17:24:13 +02:00
Dmitry Monakhov
fcb3929d38 ext4: fix extent_status fragmentation for plain files
commit 4068664e3cd2312610ceac05b74c4cf1853b8325 upstream.

Extents are cached in read_extent_tree_block(); as a result, extents
are not cached for inodes with depth == 0 when we try to find the
extent using ext4_find_extent().  The result of the lookup is cached
in ext4_map_blocks() but is only a subset of the extent on disk.  As a
result, the contents of extents status cache can get very badly
fragmented for certain workloads, such as a random 4k read workload.

File size of /mnt/test is 33554432 (8192 blocks of 4096 bytes)
 ext:     logical_offset:        physical_offset: length:   expected: flags:
   0:        0..    8191:      40960..     49151:   8192:             last,eof

$ perf record -e 'ext4:ext4_es_*' /root/bin/fio --name=t --direct=0 --rw=randread --bs=4k --filesize=32M --size=32M --filename=/mnt/test
$ perf script | grep ext4_es_insert_extent | head -n 10
             fio   131 [000]    13.975421:           ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [494/1) mapped 41454 status W
             fio   131 [000]    13.975939:           ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [6064/1) mapped 47024 status W
             fio   131 [000]    13.976467:           ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [6907/1) mapped 47867 status W
             fio   131 [000]    13.976937:           ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [3850/1) mapped 44810 status W
             fio   131 [000]    13.977440:           ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [3292/1) mapped 44252 status W
             fio   131 [000]    13.977931:           ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [6882/1) mapped 47842 status W
             fio   131 [000]    13.978376:           ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [3117/1) mapped 44077 status W
             fio   131 [000]    13.978957:           ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [2896/1) mapped 43856 status W
             fio   131 [000]    13.979474:           ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [7479/1) mapped 48439 status W

Fix this by caching the extents for inodes with depth == 0 in
ext4_find_extent().

[ Renamed ext4_es_cache_extents() to ext4_cache_extents() since this
  newly added function is not in extents_cache.c, and to avoid
  potential visual confusion with ext4_es_cache_extent().  -TYT ]

Signed-off-by: Dmitry Monakhov <dmonakhov@gmail.com>
Link: https://lore.kernel.org/r/20191106122502.19986-1-dmonakhov@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:24:11 +02:00
Jan Kara
b2c5f60ccc ext2: fix debug reference to ext2_xattr_cache
[ Upstream commit 32302085a8d90859c40cf1a5e8313f575d06ec75 ]

Fix a debug-only build error in ext2/xattr.c:

When building without extra debugging, (and with another patch that uses
no_printk() instead of <empty> for the ext2-xattr debug-print macros,
this build error happens:

../fs/ext2/xattr.c: In function ‘ext2_xattr_cache_insert’:
../fs/ext2/xattr.c:869:18: error: ‘ext2_xattr_cache’ undeclared (first use in
this function); did you mean ‘ext2_xattr_list’?
     atomic_read(&ext2_xattr_cache->c_entry_count));

Fix the problem by removing cached entry count from the debug message
since otherwise we'd have to export the mbcache structure just for that.

Fixes: be0726d33cb8 ("ext2: convert to mbcache2")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24 08:01:22 +02:00
Randy Dunlap
7ca6f11ed1 ext2: fix empty body warnings when -Wextra is used
[ Upstream commit 44a52022e7f15cbaab957df1c14f7a4f527ef7cf ]

When EXT2_ATTR_DEBUG is not defined, modify the 2 debug macros
to use the no_printk() macro instead of <nothing>.
This fixes gcc warnings when -Wextra is used:

../fs/ext2/xattr.c:252:42: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../fs/ext2/xattr.c:258:42: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../fs/ext2/xattr.c:330:42: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../fs/ext2/xattr.c:872:45: warning: suggest braces around empty body in an ‘else’ statement [-Wempty-body]

I have verified that the only object code change (with gcc 7.5.0) is
the reversal of some instructions from 'cmp a,b' to 'cmp b,a'.

Link: https://lore.kernel.org/r/e18a7395-61fb-2093-18e8-ed4f8cf56248@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jan Kara <jack@suse.com>
Cc: linux-ext4@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24 08:01:21 +02:00
Trond Myklebust
af8a66de65 NFS: Fix memory leaks in nfs_pageio_stop_mirroring()
[ Upstream commit 862f35c94730c9270833f3ad05bd758a29f204ed ]

If we just set the mirror count to 1 without first clearing out
the mirrors, we can leak queued up requests.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24 08:01:21 +02:00
Eric Sandeen
f8c6f4104f ext4: do not commit super on read-only bdev
[ Upstream commit c96e2b8564adfb8ac14469ebc51ddc1bfecb3ae2 ]

Under some circumstances we may encounter a filesystem error on a
read-only block device, and if we try to save the error info to the
superblock and commit it, we'll wind up with a noisy error and
backtrace, i.e.:

[ 3337.146838] EXT4-fs error (device pmem1p2): ext4_get_journal_inode:4634: comm mount: inode #0: comm mount: iget: illegal inode #
------------[ cut here ]------------
generic_make_request: Trying to write to read-only block-device pmem1p2 (partno 2)
WARNING: CPU: 107 PID: 115347 at block/blk-core.c:788 generic_make_request_checks+0x6b4/0x7d0
...

To avoid this, commit the error info in the superblock only if the
block device is writable.

Reported-by: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/4b6e774d-cc00-3469-7abb-108eb151071a@sandeen.net
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24 08:01:19 +02:00
Misono Tomohiro
da186a08b3 NFS: direct.c: Fix memory leak of dreq when nfs_get_lock_context fails
[ Upstream commit 8605cf0e852af3b2c771c18417499dc4ceed03d5 ]

When dreq is allocated by nfs_direct_req_alloc(), dreq->kref is
initialized to 2. Therefore we need to call nfs_direct_req_release()
twice to release the allocated dreq. Usually it is called in
nfs_file_direct_{read, write}() and nfs_direct_complete().

However, current code only calls nfs_direct_req_relese() once if
nfs_get_lock_context() fails in nfs_file_direct_{read, write}().
So, that case would result in memory leak.

Fix this by adding the missing call.

Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24 08:01:19 +02:00
Trond Myklebust
0fd0b83ac7 NFSv4/pnfs: Return valid stateids in nfs_layout_find_inode_by_stateid()
[ Upstream commit d911c57a19551c6bef116a3b55c6b089901aacb0 ]

Make sure to test the stateid for validity so that we catch instances
where the server may have been reusing stateids in
nfs_layout_find_inode_by_stateid().

Fixes: 7b410d9ce460 ("pNFS: Delay getting the layout header in CB_LAYOUTRECALL handlers")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24 08:01:18 +02:00
Roman Gushchin
73a55c0a66 ext4: use non-movable memory for superblock readahead
commit d87f639258a6a5980183f11876c884931ad93da2 upstream.

Since commit a8ac900b8163 ("ext4: use non-movable memory for the
superblock") buffers for ext4 superblock were allocated using
the sb_bread_unmovable() helper which allocated buffer heads
out of non-movable memory blocks. It was necessarily to not block
page migrations and do not cause cma allocation failures.

However commit 85c8f176a611 ("ext4: preload block group descriptors")
broke this by introducing pre-reading of the ext4 superblock.
The problem is that __breadahead() is using __getblk() underneath,
which allocates buffer heads out of movable memory.

It resulted in page migration failures I've seen on a machine
with an ext4 partition and a preallocated cma area.

Fix this by introducing sb_breadahead_unmovable() and
__breadahead_gfp() helpers which use non-movable memory for buffer
head allocations and use them for the ext4 superblock readahead.

Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Fixes: 85c8f176a611 ("ext4: preload block group descriptors")
Signed-off-by: Roman Gushchin <guro@fb.com>
Link: https://lore.kernel.org/r/20200229001411.128010-1-guro@fb.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24 08:01:00 +02:00
Jan Kara
e4598037e0 ext4: do not zeroout extents beyond i_disksize
commit 801674f34ecfed033b062a0f217506b93c8d5e8a upstream.

We do not want to create initialized extents beyond end of file because
for e2fsck it is impossible to distinguish them from a case of corrupted
file size / extent tree and so it complains like:

Inode 12, i_size is 147456, should be 163840.  Fix? no

Code in ext4_ext_convert_to_initialized() and
ext4_split_convert_extents() try to make sure it does not create
initialized extents beyond inode size however they check against
inode->i_size which is wrong. They should instead check against
EXT4_I(inode)->i_disksize which is the current inode size on disk.
That's what e2fsck is going to see in case of crash before all dirty
data is written. This bug manifests as generic/456 test failure (with
recent enough fstests where fsx got fixed to properly pass
FALLOC_KEEP_SIZE_FL flags to the kernel) when run with dioread_lock
mount option.

CC: stable@vger.kernel.org
Fixes: 21ca087a3891 ("ext4: Do not zero out uninitialized extents beyond i_size")
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20200331105016.8674-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24 08:00:57 +02:00
Josef Bacik
1d518b486e btrfs: check commit root generation in should_ignore_root
commit 4d4225fc228e46948486d8b8207955f0c031b92e upstream.

Previously we would set the reloc root's last snapshot to transid - 1.
However there was a problem with doing this, and we changed it to
setting the last snapshot to the generation of the commit node of the fs
root.

This however broke should_ignore_root().  The assumption is that if we
are in a generation newer than when the reloc root was created, then we
would find the reloc root through normal backref lookups, and thus can
ignore any fs roots we find with an old enough reloc root.

Now that the last snapshot could be considerably further in the past
than before, we'd end up incorrectly ignoring an fs root.  Thus we'd
find no nodes for the bytenr we were searching for, and we'd fail to
relocate anything.  We'd loop through the relocate code again and see
that there were still used space in that block group, attempt to
relocate those bytenr's again, fail in the same way, and just loop like
this forever.  This is tricky in that we have to not modify the fs root
at all during this time, so we need to have a block group that has data
in this fs root that is not shared by any other root, which is why this
has been difficult to reproduce.

Fixes: 054570a1dc94 ("Btrfs: fix relocation incorrectly dropping data references")
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24 08:00:56 +02:00
Josh Triplett
8eaf44acf1 ext4: fix incorrect inodes per group in error message
commit b9c538da4e52a7b79dfcf4cfa487c46125066dfb upstream.

If ext4_fill_super detects an invalid number of inodes per group, the
resulting error message printed the number of blocks per group, rather
than the number of inodes per group. Fix it to print the correct value.

Fixes: cd6bb35bf7f6d ("ext4: use more strict checks for inodes_per_block on mount")
Link: https://lore.kernel.org/r/8be03355983a08e5d4eed480944613454d7e2550.1585434649.git.josh@joshtriplett.org
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24 08:00:55 +02:00
Josh Triplett
abe9688ab0 ext4: fix incorrect group count in ext4_fill_super error message
commit df41460a21b06a76437af040d90ccee03888e8e5 upstream.

ext4_fill_super doublechecks the number of groups before mounting; if
that check fails, the resulting error message prints the group count
from the ext4_sb_info sbi, which hasn't been set yet. Print the freshly
computed group count instead (which at that point has just been computed
in "blocks_count").

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Fixes: 4ec1102813798 ("ext4: Add sanity checks for the superblock before mounting the filesystem")
Link: https://lore.kernel.org/r/8b957cd1513fcc4550fe675c10bcce2175c33a49.1585431964.git.josh@joshtriplett.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24 08:00:55 +02:00
zhangyi (F)
07fcda0a2a jbd2: improve comments about freeing data buffers whose page mapping is NULL
commit 780f66e59231fcf882f36c63f287252ee47cc75a upstream.

Improve comments in jbd2_journal_commit_transaction() to describe why
we don't need to clear the buffer_mapped bit for freeing file mapping
buffers whose page mapping is NULL.

Link: https://lore.kernel.org/r/20200217112706.20085-1-yi.zhang@huawei.com
Fixes: c96dceeabf76 ("jbd2: do not clear the BH_Mapped flag when forgetting a metadata buffer")
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24 08:00:54 +02:00
Josef Bacik
8807401c6f btrfs: use nofs allocations for running delayed items
[ Upstream commit 351cbf6e4410e7ece05e35d0a07320538f2418b4 ]

Zygo reported the following lockdep splat while testing the balance
patches

======================================================
WARNING: possible circular locking dependency detected
5.6.0-c6f0579d496a+ #53 Not tainted
------------------------------------------------------
kswapd0/1133 is trying to acquire lock:
ffff888092f622c0 (&delayed_node->mutex){+.+.}, at: __btrfs_release_delayed_node+0x7c/0x5b0

but task is already holding lock:
ffffffff8fc5f860 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x5/0x30

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (fs_reclaim){+.+.}:
       fs_reclaim_acquire.part.91+0x29/0x30
       fs_reclaim_acquire+0x19/0x20
       kmem_cache_alloc_trace+0x32/0x740
       add_block_entry+0x45/0x260
       btrfs_ref_tree_mod+0x6e2/0x8b0
       btrfs_alloc_tree_block+0x789/0x880
       alloc_tree_block_no_bg_flush+0xc6/0xf0
       __btrfs_cow_block+0x270/0x940
       btrfs_cow_block+0x1ba/0x3a0
       btrfs_search_slot+0x999/0x1030
       btrfs_insert_empty_items+0x81/0xe0
       btrfs_insert_delayed_items+0x128/0x7d0
       __btrfs_run_delayed_items+0xf4/0x2a0
       btrfs_run_delayed_items+0x13/0x20
       btrfs_commit_transaction+0x5cc/0x1390
       insert_balance_item.isra.39+0x6b2/0x6e0
       btrfs_balance+0x72d/0x18d0
       btrfs_ioctl_balance+0x3de/0x4c0
       btrfs_ioctl+0x30ab/0x44a0
       ksys_ioctl+0xa1/0xe0
       __x64_sys_ioctl+0x43/0x50
       do_syscall_64+0x77/0x2c0
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #0 (&delayed_node->mutex){+.+.}:
       __lock_acquire+0x197e/0x2550
       lock_acquire+0x103/0x220
       __mutex_lock+0x13d/0xce0
       mutex_lock_nested+0x1b/0x20
       __btrfs_release_delayed_node+0x7c/0x5b0
       btrfs_remove_delayed_node+0x49/0x50
       btrfs_evict_inode+0x6fc/0x900
       evict+0x19a/0x2c0
       dispose_list+0xa0/0xe0
       prune_icache_sb+0xbd/0xf0
       super_cache_scan+0x1b5/0x250
       do_shrink_slab+0x1f6/0x530
       shrink_slab+0x32e/0x410
       shrink_node+0x2a5/0xba0
       balance_pgdat+0x4bd/0x8a0
       kswapd+0x35a/0x800
       kthread+0x1e9/0x210
       ret_from_fork+0x3a/0x50

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(fs_reclaim);
                               lock(&delayed_node->mutex);
                               lock(fs_reclaim);
  lock(&delayed_node->mutex);

 *** DEADLOCK ***

3 locks held by kswapd0/1133:
 #0: ffffffff8fc5f860 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x5/0x30
 #1: ffffffff8fc380d8 (shrinker_rwsem){++++}, at: shrink_slab+0x1e8/0x410
 #2: ffff8881e0e6c0e8 (&type->s_umount_key#42){++++}, at: trylock_super+0x1b/0x70

stack backtrace:
CPU: 2 PID: 1133 Comm: kswapd0 Not tainted 5.6.0-c6f0579d496a+ #53
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 dump_stack+0xc1/0x11a
 print_circular_bug.isra.38.cold.57+0x145/0x14a
 check_noncircular+0x2a9/0x2f0
 ? print_circular_bug.isra.38+0x130/0x130
 ? stack_trace_consume_entry+0x90/0x90
 ? save_trace+0x3cc/0x420
 __lock_acquire+0x197e/0x2550
 ? btrfs_inode_clear_file_extent_range+0x9b/0xb0
 ? register_lock_class+0x960/0x960
 lock_acquire+0x103/0x220
 ? __btrfs_release_delayed_node+0x7c/0x5b0
 __mutex_lock+0x13d/0xce0
 ? __btrfs_release_delayed_node+0x7c/0x5b0
 ? __asan_loadN+0xf/0x20
 ? pvclock_clocksource_read+0xeb/0x190
 ? __btrfs_release_delayed_node+0x7c/0x5b0
 ? mutex_lock_io_nested+0xc20/0xc20
 ? __kasan_check_read+0x11/0x20
 ? check_chain_key+0x1e6/0x2e0
 mutex_lock_nested+0x1b/0x20
 ? mutex_lock_nested+0x1b/0x20
 __btrfs_release_delayed_node+0x7c/0x5b0
 btrfs_remove_delayed_node+0x49/0x50
 btrfs_evict_inode+0x6fc/0x900
 ? btrfs_setattr+0x840/0x840
 ? do_raw_spin_unlock+0xa8/0x140
 evict+0x19a/0x2c0
 dispose_list+0xa0/0xe0
 prune_icache_sb+0xbd/0xf0
 ? invalidate_inodes+0x310/0x310
 super_cache_scan+0x1b5/0x250
 do_shrink_slab+0x1f6/0x530
 shrink_slab+0x32e/0x410
 ? do_shrink_slab+0x530/0x530
 ? do_shrink_slab+0x530/0x530
 ? __kasan_check_read+0x11/0x20
 ? mem_cgroup_protected+0x13d/0x260
 shrink_node+0x2a5/0xba0
 balance_pgdat+0x4bd/0x8a0
 ? mem_cgroup_shrink_node+0x490/0x490
 ? _raw_spin_unlock_irq+0x27/0x40
 ? finish_task_switch+0xce/0x390
 ? rcu_read_lock_bh_held+0xb0/0xb0
 kswapd+0x35a/0x800
 ? _raw_spin_unlock_irqrestore+0x4c/0x60
 ? balance_pgdat+0x8a0/0x8a0
 ? finish_wait+0x110/0x110
 ? __kasan_check_read+0x11/0x20
 ? __kthread_parkme+0xc6/0xe0
 ? balance_pgdat+0x8a0/0x8a0
 kthread+0x1e9/0x210
 ? kthread_create_worker_on_cpu+0xc0/0xc0
 ret_from_fork+0x3a/0x50

This is because we hold that delayed node's mutex while doing tree
operations.  Fix this by just wrapping the searches in nofs.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24 08:00:48 +02:00
Filipe Manana
049be58476 Btrfs: fix crash during unmount due to race with delayed inode workers
[ Upstream commit f0cc2cd70164efe8f75c5d99560f0f69969c72e4 ]

During unmount we can have a job from the delayed inode items work queue
still running, that can lead to at least two bad things:

1) A crash, because the worker can try to create a transaction just
   after the fs roots were freed;

2) A transaction leak, because the worker can create a transaction
   before the fs roots are freed and just after we committed the last
   transaction and after we stopped the transaction kthread.

A stack trace example of the crash:

 [79011.691214] kernel BUG at lib/radix-tree.c:982!
 [79011.692056] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
 [79011.693180] CPU: 3 PID: 1394 Comm: kworker/u8:2 Tainted: G        W         5.6.0-rc2-btrfs-next-54 #2
 (...)
 [79011.696789] Workqueue: btrfs-delayed-meta btrfs_work_helper [btrfs]
 [79011.697904] RIP: 0010:radix_tree_tag_set+0xe7/0x170
 (...)
 [79011.702014] RSP: 0018:ffffb3c84a317ca0 EFLAGS: 00010293
 [79011.702949] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
 [79011.704202] RDX: ffffb3c84a317cb0 RSI: ffffb3c84a317ca8 RDI: ffff8db3931340a0
 [79011.705463] RBP: 0000000000000005 R08: 0000000000000005 R09: ffffffff974629d0
 [79011.706756] R10: ffffb3c84a317bc0 R11: 0000000000000001 R12: ffff8db393134000
 [79011.708010] R13: ffff8db3931340a0 R14: ffff8db393134068 R15: 0000000000000001
 [79011.709270] FS:  0000000000000000(0000) GS:ffff8db3b6a00000(0000) knlGS:0000000000000000
 [79011.710699] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [79011.711710] CR2: 00007f22c2a0a000 CR3: 0000000232ad4005 CR4: 00000000003606e0
 [79011.712958] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 [79011.714205] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 [79011.715448] Call Trace:
 [79011.715925]  record_root_in_trans+0x72/0xf0 [btrfs]
 [79011.716819]  btrfs_record_root_in_trans+0x4b/0x70 [btrfs]
 [79011.717925]  start_transaction+0xdd/0x5c0 [btrfs]
 [79011.718829]  btrfs_async_run_delayed_root+0x17e/0x2b0 [btrfs]
 [79011.719915]  btrfs_work_helper+0xaa/0x720 [btrfs]
 [79011.720773]  process_one_work+0x26d/0x6a0
 [79011.721497]  worker_thread+0x4f/0x3e0
 [79011.722153]  ? process_one_work+0x6a0/0x6a0
 [79011.722901]  kthread+0x103/0x140
 [79011.723481]  ? kthread_create_worker_on_cpu+0x70/0x70
 [79011.724379]  ret_from_fork+0x3a/0x50
 (...)

The following diagram shows a sequence of steps that lead to the crash
during ummount of the filesystem:

        CPU 1                                             CPU 2                                CPU 3

 btrfs_punch_hole()
   btrfs_btree_balance_dirty()
     btrfs_balance_delayed_items()
       --> sees
           fs_info->delayed_root->items
           with value 200, which is greater
           than
           BTRFS_DELAYED_BACKGROUND (128)
           and smaller than
           BTRFS_DELAYED_WRITEBACK (512)
       btrfs_wq_run_delayed_node()
         --> queues a job for
             fs_info->delayed_workers to run
             btrfs_async_run_delayed_root()

                                                                                            btrfs_async_run_delayed_root()
                                                                                              --> job queued by CPU 1

                                                                                              --> starts picking and running
                                                                                                  delayed nodes from the
                                                                                                  prepare_list list

                                                 close_ctree()

                                                   btrfs_delete_unused_bgs()

                                                   btrfs_commit_super()

                                                     btrfs_join_transaction()
                                                       --> gets transaction N

                                                     btrfs_commit_transaction(N)
                                                       --> set transaction state
                                                        to TRANTS_STATE_COMMIT_START

                                                                                             btrfs_first_prepared_delayed_node()
                                                                                               --> picks delayed node X through
                                                                                                   the prepared_list list

                                                       btrfs_run_delayed_items()

                                                         btrfs_first_delayed_node()
                                                           --> also picks delayed node X
                                                               but through the node_list
                                                               list

                                                         __btrfs_commit_inode_delayed_items()
                                                            --> runs all delayed items from
                                                                this node and drops the
                                                                node's item count to 0
                                                                through call to
                                                                btrfs_release_delayed_inode()

                                                         --> finishes running any remaining
                                                             delayed nodes

                                                       --> finishes transaction commit

                                                   --> stops cleaner and transaction threads

                                                   btrfs_free_fs_roots()
                                                     --> frees all roots and removes them
                                                         from the radix tree
                                                         fs_info->fs_roots_radix

                                                                                             btrfs_join_transaction()
                                                                                               start_transaction()
                                                                                                 btrfs_record_root_in_trans()
                                                                                                   record_root_in_trans()
                                                                                                     radix_tree_tag_set()
                                                                                                       --> crashes because
                                                                                                           the root is not in
                                                                                                           the radix tree
                                                                                                           anymore

If the worker is able to call btrfs_join_transaction() before the unmount
task frees the fs roots, we end up leaking a transaction and all its
resources, since after the call to btrfs_commit_super() and stopping the
transaction kthread, we don't expect to have any transaction open anymore.

When this situation happens the worker has a delayed node that has no
more items to run, since the task calling btrfs_run_delayed_items(),
which is doing a transaction commit, picks the same node and runs all
its items first.

We can not wait for the worker to complete when running delayed items
through btrfs_run_delayed_items(), because we call that function in
several phases of a transaction commit, and that could cause a deadlock
because the worker calls btrfs_join_transaction() and the task doing the
transaction commit may have already set the transaction state to
TRANS_STATE_COMMIT_DOING.

Also it's not possible to get into a situation where only some of the
items of a delayed node are added to the fs/subvolume tree in the current
transaction and the remaining ones in the next transaction, because when
running the items of a delayed inode we lock its mutex, effectively
waiting for the worker if the worker is running the items of the delayed
node already.

Since this can only cause issues when unmounting a filesystem, fix it in
a simple way by waiting for any jobs on the delayed workers queue before
calling btrfs_commit_supper() at close_ctree(). This works because at this
point no one can call btrfs_btree_balance_dirty() or
btrfs_balance_delayed_items(), and if we end up waiting for any worker to
complete, btrfs_commit_super() will commit the transaction created by the
worker.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24 08:00:48 +02:00
Simon Gander
df54882393 hfsplus: fix crash and filesystem corruption when deleting files
commit 25efb2ffdf991177e740b2f63e92b4ec7d310a92 upstream.

When removing files containing extended attributes, the hfsplus driver may
remove the wrong entries from the attributes b-tree, causing major
filesystem damage and in some cases even kernel crashes.

To remove a file, all its extended attributes have to be removed as well.
The driver does this by looking up all keys in the attributes b-tree with
the cnid of the file.  Each of these entries then gets deleted using the
key used for searching, which doesn't contain the attribute's name when it
should.  Since the key doesn't contain the name, the deletion routine will
not find the correct entry and instead remove the one in front of it.  If
parent nodes have to be modified, these become corrupt as well.  This
causes invalid links and unsorted entries that not even macOS's fsck_hfs
is able to fix.

To fix this, modify the search key before an entry is deleted from the
attributes b-tree by copying the found entry's key into the search key,
therefore ensuring that the correct entry gets removed from the tree.

Signed-off-by: Simon Gander <simon@tuxera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Anton Altaparmakov <anton@tuxera.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200327155541.1521-1-simon@tuxera.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24 08:00:45 +02:00
Changwei Ge
0353bad391 ocfs2: no need try to truncate file beyond i_size
commit 783fda856e1034dee90a873f7654c418212d12d7 upstream.

Linux fallocate(2) with FALLOC_FL_PUNCH_HOLE mode set, its offset can
exceed the inode size.  Ocfs2 now doesn't allow that offset beyond inode
size.  This restriction is not necessary and violates fallocate(2)
semantics.

If fallocate(2) offset is beyond inode size, just return success and do
nothing further.

Otherwise, ocfs2 will crash the kernel.

  kernel BUG at fs/ocfs2//alloc.c:7264!
   ocfs2_truncate_inline+0x20f/0x360 [ocfs2]
   ocfs2_remove_inode_range+0x23c/0xcb0 [ocfs2]
   __ocfs2_change_file_space+0x4a5/0x650 [ocfs2]
   ocfs2_fallocate+0x83/0xa0 [ocfs2]
   vfs_fallocate+0x148/0x230
   SyS_fallocate+0x48/0x80
   do_syscall_64+0x79/0x170

Signed-off-by: Changwei Ge <chge@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200407082754.17565-1-chge@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24 08:00:43 +02:00
Eric Biggers
8fbb1f4232 fs/filesystems.c: downgrade user-reachable WARN_ONCE() to pr_warn_once()
commit 26c5d78c976ca298e59a56f6101a97b618ba3539 upstream.

After request_module(), nothing is stopping the module from being
unloaded until someone takes a reference to it via try_get_module().

The WARN_ONCE() in get_fs_type() is thus user-reachable, via userspace
running 'rmmod' concurrently.

Since WARN_ONCE() is for kernel bugs only, not for user-reachable
situations, downgrade this warning to pr_warn_once().

Keep it printed once only, since the intent of this warning is to detect
a bug in modprobe at boot time.  Printing the warning more than once
wouldn't really provide any useful extra information.

Fixes: 41124db869b7 ("fs: warn in case userspace lied about modprobe return")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jessica Yu <jeyu@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: NeilBrown <neilb@suse.com>
Cc: <stable@vger.kernel.org>		[4.13+]
Link: http://lkml.kernel.org/r/20200312202552.241885-3-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24 08:00:43 +02:00
Qian Cai
0ee19b5a3e ext4: fix a data race at inode->i_blocks
commit 28936b62e71e41600bab319f262ea9f9b1027629 upstream.

inode->i_blocks could be accessed concurrently as noticed by KCSAN,

 BUG: KCSAN: data-race in ext4_do_update_inode [ext4] / inode_add_bytes

 write to 0xffff9a00d4b982d0 of 8 bytes by task 22100 on cpu 118:
  inode_add_bytes+0x65/0xf0
  __inode_add_bytes at fs/stat.c:689
  (inlined by) inode_add_bytes at fs/stat.c:702
  ext4_mb_new_blocks+0x418/0xca0 [ext4]
  ext4_ext_map_blocks+0x1a6b/0x27b0 [ext4]
  ext4_map_blocks+0x1a9/0x950 [ext4]
  _ext4_get_block+0xfc/0x270 [ext4]
  ext4_get_block_unwritten+0x33/0x50 [ext4]
  __block_write_begin_int+0x22e/0xae0
  __block_write_begin+0x39/0x50
  ext4_write_begin+0x388/0xb50 [ext4]
  ext4_da_write_begin+0x35f/0x8f0 [ext4]
  generic_perform_write+0x15d/0x290
  ext4_buffered_write_iter+0x11f/0x210 [ext4]
  ext4_file_write_iter+0xce/0x9e0 [ext4]
  new_sync_write+0x29c/0x3b0
  __vfs_write+0x92/0xa0
  vfs_write+0x103/0x260
  ksys_write+0x9d/0x130
  __x64_sys_write+0x4c/0x60
  do_syscall_64+0x91/0xb05
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 read to 0xffff9a00d4b982d0 of 8 bytes by task 8 on cpu 65:
  ext4_do_update_inode+0x4a0/0xf60 [ext4]
  ext4_inode_blocks_set at fs/ext4/inode.c:4815
  ext4_mark_iloc_dirty+0xaf/0x160 [ext4]
  ext4_mark_inode_dirty+0x129/0x3e0 [ext4]
  ext4_convert_unwritten_extents+0x253/0x2d0 [ext4]
  ext4_convert_unwritten_io_end_vec+0xc5/0x150 [ext4]
  ext4_end_io_rsv_work+0x22c/0x350 [ext4]
  process_one_work+0x54f/0xb90
  worker_thread+0x80/0x5f0
  kthread+0x1cd/0x1f0
  ret_from_fork+0x27/0x50

 4 locks held by kworker/u256:0/8:
  #0: ffff9a025abc4328 ((wq_completion)ext4-rsv-conversion){+.+.}, at: process_one_work+0x443/0xb90
  #1: ffffab5a862dbe20 ((work_completion)(&ei->i_rsv_conversion_work)){+.+.}, at: process_one_work+0x443/0xb90
  #2: ffff9a025a9d0f58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2]
  #3: ffff9a00d4b985d8 (&(&ei->i_raw_lock)->rlock){+.+.}, at: ext4_do_update_inode+0xaa/0xf60 [ext4]
 irq event stamp: 3009267
 hardirqs last  enabled at (3009267): [<ffffffff980da9b7>] __find_get_block+0x107/0x790
 hardirqs last disabled at (3009266): [<ffffffff980da8f9>] __find_get_block+0x49/0x790
 softirqs last  enabled at (3009230): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c
 softirqs last disabled at (3009223): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 65 PID: 8 Comm: kworker/u256:0 Tainted: G L 5.6.0-rc2-next-20200221+ #7
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019
 Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work [ext4]

The plain read is outside of inode->i_lock critical section which
results in a data race. Fix it by adding READ_ONCE() there.

Link: https://lore.kernel.org/r/20200222043258.2279-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24 08:00:43 +02:00
Trond Myklebust
c60aee180b NFS: Fix a page leak in nfs_destroy_unlinked_subrequests()
commit add42de31721fa29ed77a7ce388674d69f9d31a4 upstream.

When we detach a subrequest from the list, we must also release the
reference it holds to the parent.

Fixes: 5b2b5187fa85 ("NFS: Fix nfs_page_group_destroy() and nfs_lock_and_join_requests() race cases")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24 08:00:43 +02:00
Josef Bacik
25f78b3ce3 btrfs: drop block from cache on error in relocation
commit 8e19c9732ad1d127b5575a10f4fbcacf740500ff upstream.

If we have an error while building the backref tree in relocation we'll
process all the pending edges and then free the node.  However if we
integrated some edges into the cache we'll lose our link to those edges
by simply freeing this node, which means we'll leak memory and
references to any roots that we've found.

Instead we need to use remove_backref_node(), which walks through all of
the edges that are still linked to this node and free's them up and
drops any root references we may be holding.

CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24 08:00:40 +02:00
Yilu Lin
620b7966d4 CIFS: Fix bug which the return value by asynchronous read is error
commit 97adda8b3ab703de8e4c8d27646ddd54fe22879c upstream.

This patch is used to fix the bug in collect_uncached_read_data()
that rc is automatically converted from a signed number to an
unsigned number when the CIFS asynchronous read fails.
It will cause ctx->rc is error.

Example:
Share a directory and create a file on the Windows OS.
Mount the directory to the Linux OS using CIFS.
On the CIFS client of the Linux OS, invoke the pread interface to
deliver the read request.

The size of the read length plus offset of the read request is greater
than the maximum file size.

In this case, the CIFS server on the Windows OS returns a failure
message (for example, the return value of
smb2.nt_status is STATUS_INVALID_PARAMETER).

After receiving the response message, the CIFS client parses
smb2.nt_status to STATUS_INVALID_PARAMETER
and converts it to the Linux error code (rdata->result=-22).

Then the CIFS client invokes the collect_uncached_read_data function to
assign the value of rdata->result to rc, that is, rc=rdata->result=-22.

The type of the ctx->total_len variable is unsigned integer,
the type of the rc variable is integer, and the type of
the ctx->rc variable is ssize_t.

Therefore, during the ternary operation, the value of rc is
automatically converted to an unsigned number. The final result is
ctx->rc=4294967274. However, the expected result is ctx->rc=-22.

Signed-off-by: Yilu Lin <linyilu@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24 08:00:40 +02:00
Eric W. Biederman
28c63ef17d signal: Extend exec_id to 64bits
commit d1e7fd6462ca9fc76650fbe6ca800e35b24267da upstream.

Replace the 32bit exec_id with a 64bit exec_id to make it impossible
to wrap the exec_id counter.  With care an attacker can cause exec_id
wrap and send arbitrary signals to a newly exec'd parent.  This
bypasses the signal sending checks if the parent changes their
credentials during exec.

The severity of this problem can been seen that in my limited testing
of a 32bit exec_id it can take as little as 19s to exec 65536 times.
Which means that it can take as little as 14 days to wrap a 32bit
exec_id.  Adam Zabrocki has succeeded wrapping the self_exe_id in 7
days.  Even my slower timing is in the uptime of a typical server.
Which means self_exec_id is simply a speed bump today, and if exec
gets noticably faster self_exec_id won't even be a speed bump.

Extending self_exec_id to 64bits introduces a problem on 32bit
architectures where reading self_exec_id is no longer atomic and can
take two read instructions.  Which means that is is possible to hit
a window where the read value of exec_id does not match the written
value.  So with very lucky timing after this change this still
remains expoiltable.

I have updated the update of exec_id on exec to use WRITE_ONCE
and the read of exec_id in do_notify_parent to use READ_ONCE
to make it clear that there is no locking between these two
locations.

Link: https://lore.kernel.org/kernel-hardening/20200324215049.GA3710@pi3.com.pl
Fixes: 2.3.23pre2
Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24 08:00:38 +02:00
Josef Bacik
2ee871239d btrfs: track reloc roots based on their commit root bytenr
[ Upstream commit ea287ab157c2816bf12aad4cece41372f9d146b4 ]

We always search the commit root of the extent tree for looking up back
references, however we track the reloc roots based on their current
bytenr.

This is wrong, if we commit the transaction between relocating tree
blocks we could end up in this code in build_backref_tree

  if (key.objectid == key.offset) {
	  /*
	   * Only root blocks of reloc trees use backref
	   * pointing to itself.
	   */
	  root = find_reloc_root(rc, cur->bytenr);
	  ASSERT(root);
	  cur->root = root;
	  break;
  }

find_reloc_root() is looking based on the bytenr we had in the commit
root, but if we've COWed this reloc root we will not find that bytenr,
and we will trip over the ASSERT(root).

Fix this by using the commit_root->start bytenr for indexing the commit
root.  Then we change the __update_reloc_root() caller to be used when
we switch the commit root for the reloc root during commit.

This fixes the panic I was seeing when we started throttling relocation
for delayed refs.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24 08:00:30 +02:00
Josef Bacik
c77f5f0351 btrfs: remove a BUG_ON() from merge_reloc_roots()
[ Upstream commit 7b7b74315b24dc064bc1c683659061c3d48f8668 ]

This was pretty subtle, we default to reloc roots having 0 root refs, so
if we crash in the middle of the relocation they can just be deleted.
If we successfully complete the relocation operations we'll set our root
refs to 1 in prepare_to_merge() and then go on to merge_reloc_roots().

At prepare_to_merge() time if any of the reloc roots have a 0 reference
still, we will remove that reloc root from our reloc root rb tree, and
then clean it up later.

However this only happens if we successfully start a transaction.  If
we've aborted previously we will skip this step completely, and only
have reloc roots with a reference count of 0, but were never properly
removed from the reloc control's rb tree.

This isn't a problem per-se, our references are held by the list the
reloc roots are on, and by the original root the reloc root belongs to.
If we end up in this situation all the reloc roots will be added to the
dirty_reloc_list, and then properly dropped at that point.  The reloc
control will be free'd and the rb tree is no longer used.

There were two options when fixing this, one was to remove the BUG_ON(),
the other was to make prepare_to_merge() handle the case where we
couldn't start a trans handle.

IMO this is the cleaner solution.  I started with handling the error in
prepare_to_merge(), but it turned out super ugly.  And in the end this
BUG_ON() simply doesn't matter, the cleanup was happening properly, we
were just panicing because this BUG_ON() only matters in the success
case.  So I've opted to just remove it and add a comment where it was.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24 08:00:30 +02:00
Bob Peterson
790829dc62 gfs2: Don't demote a glock until its revokes are written
[ Upstream commit df5db5f9ee112e76b5202fbc331f990a0fc316d6 ]

Before this patch, run_queue would demote glocks based on whether
there are any more holders. But if the glock has pending revokes that
haven't been written to the media, giving up the glock might end in
file system corruption if the revokes never get written due to
io errors, node crashes and fences, etc. In that case, another node
will replay the metadata blocks associated with the glock, but
because the revoke was never written, it could replay that block
even though the glock had since been granted to another node who
might have made changes.

This patch changes the logic in run_queue so that it never demotes
a glock until its count of pending revokes reaches zero.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24 08:00:27 +02:00
Ilya Dryomov
4452a6c44d ceph: canonicalize server path in place
commit b27a939e8376a3f1ed09b9c33ef44d20f18ec3d0 upstream.

syzbot reported that 4fbc0c711b24 ("ceph: remove the extra slashes in
the server path") had caused a regression where an allocation could be
done under a spinlock -- compare_mount_options() is called by sget_fc()
with sb_lock held.

We don't really need the supplied server path, so canonicalize it
in place and compare it directly.  To make this work, the leading
slash is kept around and the logic in ceph_real_mount() to skip it
is restored.  CEPH_MSG_CLIENT_SESSION now reports the same (i.e.
canonicalized) path, with the leading slash of course.

Fixes: 4fbc0c711b24 ("ceph: remove the extra slashes in the server path")
Reported-by: syzbot+98704a51af8e3d9425a9@syzkaller.appspotmail.com
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Luis Henriques <lhenriques@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-13 10:34:35 +02:00
Xiubo Li
9218bca65e ceph: remove the extra slashes in the server path
commit 4fbc0c711b2464ee1551850b85002faae0b775d5 upstream.

It's possible to pass the mount helper a server path that has more
than one contiguous slash character. For example:

  $ mount -t ceph 192.168.195.165:40176:/// /mnt/cephfs/

In the MDS server side the extra slashes of the server path will be
treated as snap dir, and then we can get the following debug logs:

  ceph:  mount opening path //
  ceph:  open_root_inode opening '//'
  ceph:  fill_trace 0000000059b8a3bc is_dentry 0 is_target 1
  ceph:  alloc_inode 00000000dc4ca00b
  ceph:  get_inode created new inode 00000000dc4ca00b 1.ffffffffffffffff ino 1
  ceph:  get_inode on 1=1.ffffffffffffffff got 00000000dc4ca00b

And then when creating any new file or directory under the mount
point, we can hit the following BUG_ON in ceph_fill_trace():

  BUG_ON(ceph_snap(dir) != dvino.snap);

Have the client ignore the extra slashes in the server path when
mounting. This will also canonicalize the path, so that identical mounts
can be consilidated.

1) "//mydir1///mydir//"
2) "/mydir1/mydir"
3) "/mydir1/mydir/"

Regardless of the internal treatment of these paths, the kernel still
stores the original string including the leading '/' for presentation
to userland.

URL: https://tracker.ceph.com/issues/42771
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Luis Henriques <lhenriques@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-13 10:34:34 +02:00