From e502babe0a85226f2417b60a8710cf8192879180 Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Tue, 7 Feb 2012 10:49:39 +0400 Subject: 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 Acked-by: David Rientjes Signed-off-by: Greg Kroah-Hartman --- drivers/tty/sysrq.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c index 7867b7c4538e..a1bcad7ef739 100644 --- a/drivers/tty/sysrq.c +++ b/drivers/tty/sysrq.c @@ -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) -- cgit v1.2.3