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| author | Aleksa Sarai <cyphar@cyphar.com> | 2023-07-14 00:09:58 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-09-13 09:43:02 +0200 |
| commit | 316a4a329a4d30eae930ec780a5c9483b65124ec (patch) | |
| tree | 6b63639813d653045135a4b06df43a68391ea95f | |
| parent | 5e4e9900e6fa61302c26d028830b271997bf329f (diff) | |
| download | linux-stable-316a4a329a4d30eae930ec780a5c9483b65124ec.tar.gz linux-stable-316a4a329a4d30eae930ec780a5c9483b65124ec.tar.bz2 linux-stable-316a4a329a4d30eae930ec780a5c9483b65124ec.zip | |
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>
| -rw-r--r-- | fs/proc/base.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 9e479d7d202b..74442e01793f 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -3581,7 +3581,8 @@ static int proc_tid_comm_permission(struct user_namespace *mnt_userns, } static const struct inode_operations proc_tid_comm_inode_operations = { - .permission = proc_tid_comm_permission, + .setattr = proc_setattr, + .permission = proc_tid_comm_permission, }; /* |