Aleksa Sarai 7e388d0f9c procfs: block chmod on /proc/thread-self/comm ...

commit ccf61486fe1e1a48e18c638d1813cda77b3c0737 upstream.

Due to an oversight in commit 1b3044e39a89 ("procfs: fix pthread
cross-thread naming if !PR_DUMPABLE") in switching from REG to NOD,
chmod operations on /proc/thread-self/comm were no longer blocked as
they are on almost all other procfs files.

A very similar situation with /proc/self/environ was used to as a root
exploit a long time ago, but procfs has SB_I_NOEXEC so this is simply a
correctness issue.

Ref: https://lwn.net/Articles/191954/
Ref: 6d76fa58b050 ("Don't allow chmod() on the /proc/<pid>/ files")
Fixes: 1b3044e39a89 ("procfs: fix pthread cross-thread naming if !PR_DUMPABLE")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Message-Id: <20230713141001.27046-1-cyphar@cyphar.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2023-09-23 10:47:00 +02:00

..

array.c

fs/proc/array.c: allow reporting eip/esp for all coredumping threads

2019-07-03 13:15:59 +02:00

base.c

procfs: block chmod on /proc/thread-self/comm

2023-09-23 10:47:00 +02:00

cmdline.c

…

consoles.c

…

cpuinfo.c

…

devices.c

…

fd.c

…

fd.h

…

generic.c

…

inode.c

proc: Use new_inode not new_inode_pseudo

2020-06-20 10:25:04 +02:00

internal.h

…

interrupts.c

…

Kconfig

…

kcore.c

…

kmsg.c

…

loadavg.c

…

Makefile

…

meminfo.c

…

namespaces.c

…

nommu.c

…

page.c

fs/proc/page.c: don't access uninitialized memmaps in fs/proc/page.c

2019-10-29 09:17:37 +01:00

proc_net.c

…

proc_sysctl.c

sysctl: add a new register_sysctl_init() interface

2023-02-06 07:46:33 +01:00

proc_tty.c

…

root.c

…

self.c

proc: don't allow async path resolution of /proc/self components

2020-12-02 08:34:41 +01:00

softirqs.c

…

stat.c

…

task_mmu.c

mm: hugetlb: proc: check for hugetlb shared PMD in /proc/PID/smaps

2023-02-22 12:46:03 +01:00

task_nommu.c

…

thread_self.c

proc: Use new_inode not new_inode_pseudo

2020-06-20 10:25:04 +02:00

uptime.c

…

version.c

…

vmcore.c

proc/vmcore: fix clearing user buffer by properly using clear_user()

2021-12-08 08:46:52 +01:00