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| author | Alexey Dobriyan <adobriyan@gmail.com> | 2018-04-21 00:56:03 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-21 03:18:35 +0300 |
| commit | 2e0ad552f5f8cd0fda02bc45fcd2b89821c62fd1 (patch) | |
| tree | 1b22f2e03dc3d0e82048a454b3daeb5e54efd11b | |
| parent | 1e6306652ba18723015d1b4967fe9de55f042499 (diff) | |
| download | linux-2e0ad552f5f8cd0fda02bc45fcd2b89821c62fd1.tar.xz | |
proc: revalidate kernel thread inodes to root:root
task_dump_owner() has the following code:
mm = task->mm;
if (mm) {
if (get_dumpable(mm) != SUID_DUMP_USER) {
uid = ...
}
}
Check for ->mm is buggy -- kernel thread might be borrowing mm
and inode will go to some random uid:gid pair.
Link: http://lkml.kernel.org/r/20180412220109.GA20978@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/proc/base.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index eafa39a3a88c..1b2ede6abcdf 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1693,6 +1693,12 @@ void task_dump_owner(struct task_struct *task, umode_t mode, kuid_t uid; kgid_t gid; + if (unlikely(task->flags & PF_KTHREAD)) { + *ruid = GLOBAL_ROOT_UID; + *rgid = GLOBAL_ROOT_GID; + return; + } + /* Default to the tasks effective ownership */ rcu_read_lock(); cred = __task_cred(task); |