Messages in this thread Patch in this message | | | Date | Fri, 13 Apr 2018 01:01:09 +0300 | From | Alexey Dobriyan <> | Subject | [PATCH] 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.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> ---
fs/proc/base.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- 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);
| |