Commit 5bf2fedc authored by Bernd Edlinger's avatar Bernd Edlinger Committed by Kees Cook
Browse files

exec: Copy oldsighand->action under spin-lock 



unshare_sighand should only access oldsighand->action
while holding oldsighand->siglock, to make sure that
newsighand->action is in a consistent state.

Signed-off-by: default avatarBernd Edlinger <bernd.edlinger@hotmail.de>
Cc: stable@vger.kernel.org
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/AM8PR10MB470871DEBD1DED081F9CC391E4389@AM8PR10MB4708.EURPRD10.PROD.OUTLOOK.COM
parent 9abf2313

fs/exec.c

+2 −2
Original line number Diff line number Diff line
@@ -1197,11 +1197,11 @@ static int unshare_sighand(struct task_struct *me) 
			return -ENOMEM;



		refcount_set(&newsighand->count, 1);

		memcpy(newsighand->action, oldsighand->action,

		       sizeof(newsighand->action));



		write_lock_irq(&tasklist_lock);

		spin_lock(&oldsighand->siglock);

		memcpy(newsighand->action, oldsighand->action,

		       sizeof(newsighand->action));

		rcu_assign_pointer(me->sighand, newsighand);

		spin_unlock(&oldsighand->siglock);

		write_unlock_irq(&tasklist_lock);