Commit e502babe authored Feb 07, 2012 by Anton Vorontsov Committed by Greg Kroah-Hartman Feb 09, 2012

sysrq: Fix possible race with exiting task



sysrq should grab the tasklist lock, otherwise calling force_sig() is
not safe, as it might race with exiting task, which ->sighand might be
set to NULL already.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 6f56d0f4

drivers/tty/sysrq.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -322,11 +322,13 @@ static void send_sig_all(int sig)
		{
		struct task_struct *p;

		read_lock(&tasklist_lock);
		for_each_process(p) {
		if (p->mm && !is_global_init(p))
		/* Not swapper, init nor kernel thread */
		force_sig(sig, p);
		}
		read_unlock(&tasklist_lock);
		}

		static void sysrq_handle_term(int key)