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>
1 file changed