Hey Linus,
/* Summary */
Mode changes to files under /proc/<pid>/ aren't supported ever since
6d76fa58b050 ("Don't allow chmod() on the /proc/<pid>/ files").
Due to an oversight in commit 1b3044e39a89 ("procfs: fix pthread
cross-thread naming if !PR_DUMPABLE") in switching from REG to NOD,
mode changes on /proc/thread-self/comm were accidently allowed.
Similar, mode changes for all files beneath /proc/<pid>/net/ are blocked
but mode changes on /proc/<pid>/net itself were accidently allowed.
Both issues come down to not using the generic proc_setattr() helper
which blocks all mode changes. This is rectified with this pull request.
This also removes a strange nolibc test that abused /proc/<pid>/net for
testing mode changes. Using procfs for this test never made a lot of
sense given procfs has special semantics for almost everything anway.
Both changes are minor user-visible changes. It is however very unlikely
that mode changes on proc/<pid>/net and /proc/thread-self/comm are
something that userspace relies on.
/* Testing */
clang: Ubuntu clang version 15.0.7
gcc: (Ubuntu 12.2.0-3ubuntu1) 12.2.0
All patches are based on v6.5-rc1 and have been sitting in linux-next.
No build failures or warnings were observed.
/* Conflicts */
(1) linux-next: manual merge of the nolibc tree with the vfs-brauner tree
https://lore.kernel.org/lkml/20230824141008.27f7270b@xxxxxxxxxxxxxxxx
The following changes since commit 06c2afb862f9da8dc5efa4b6076a0e48c3fbaaa5:
Linux 6.5-rc1 (2023-07-09 13:53:13 -0700)
are available in the Git repository at:
git@xxxxxxxxxxxxxxxxxxx:pub/scm/linux/kernel/git/vfs/vfs tags/v6.6-fs.proc.uapi
for you to fetch changes up to ccf61486fe1e1a48e18c638d1813cda77b3c0737:
procfs: block chmod on /proc/thread-self/comm (2023-07-13 16:30:52 +0200)
Please consider pulling these changes from the signed v6.6-fs.proc.uapi tag.
Thanks!
Christian
----------------------------------------------------------------
v6.6-fs.proc.uapi
----------------------------------------------------------------
Aleksa Sarai (1):
procfs: block chmod on /proc/thread-self/comm
Thomas Weißschuh (2):
selftests/nolibc: drop test chmod_net
proc: use generic setattr() for /proc/$PID/net
fs/proc/base.c | 3 ++-
fs/proc/proc_net.c | 1 +
tools/testing/selftests/nolibc/nolibc-test.c | 1 -
3 files changed, 3 insertions(+), 2 deletions(-)
