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Commit 432870da authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
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exit_notify: kill the wrong capable(CAP_KILL) check 



The CAP_KILL check in exit_notify() looks just wrong, kill it.

Whatever logic we have to reset ->exit_signal, the malicious user
can bypass it if it execs the setuid application before exiting.

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
Acked-by: default avatarRoland McGrath <roland@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 22ae77bc

kernel/exit.c

+1 −2
Original line number Diff line number Diff line
@@ -837,8 +837,7 @@ static void exit_notify(struct task_struct *tsk, int group_dead) 
	 */

	if (tsk->exit_signal != SIGCHLD && !task_detached(tsk) &&

	    (tsk->parent_exec_id != tsk->real_parent->self_exec_id ||

	     tsk->self_exec_id != tsk->parent_exec_id) &&

	    !capable(CAP_KILL))

	     tsk->self_exec_id != tsk->parent_exec_id))

		tsk->exit_signal = SIGCHLD;



	signal = tracehook_notify_death(tsk, &cookie, group_dead);