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| author | Alexey Dobriyan <adobriyan@gmail.com> | 2018-04-20 14:56:03 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-06-21 04:02:46 +0900 |
| commit | d497efd805fe5e2c2bd77f98bcc0f1700f090f0b (patch) | |
| tree | b179ba94101ce895d6348e542705ea619ef037a1 /fs/proc/base.c | |
| parent | a20600762300154bb6ed99eea6b16abd1163dbea (diff) | |
| download | linux-exynos-d497efd805fe5e2c2bd77f98bcc0f1700f090f0b.tar.gz linux-exynos-d497efd805fe5e2c2bd77f98bcc0f1700f090f0b.tar.bz2 linux-exynos-d497efd805fe5e2c2bd77f98bcc0f1700f090f0b.zip | |
proc: revalidate kernel thread inodes to root:root
[ Upstream commit 2e0ad552f5f8cd0fda02bc45fcd2b89821c62fd1 ]
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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/proc/base.c')
| -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 dd9d4d3a2e39..c5c42f3e33d1 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1694,6 +1694,12 @@ void task_dump_owner(struct task_struct *task, mode_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); |