Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751294AbWHSPG3 (ORCPT ); Sat, 19 Aug 2006 11:06:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751419AbWHSPG2 (ORCPT ); Sat, 19 Aug 2006 11:06:28 -0400 Received: from filfla-vlan276.msk.corbina.net ([213.234.233.49]:16798 "EHLO screens.ru") by vger.kernel.org with ESMTP id S1751294AbWHSPG2 (ORCPT ); Sat, 19 Aug 2006 11:06:28 -0400 Date: Sat, 19 Aug 2006 23:30:27 +0400 From: Oleg Nesterov To: Andrew Morton Cc: Thomas Gleixner , Ingo Molnar , Steven Rostedt , Nick Piggin , Linus Torvalds , linux-kernel@vger.kernel.org Subject: [PATCH 1/4] for 2.6.18, revert "Drop tasklist lock in do_sched_setscheduler" Message-ID: <20060819193026.GA7449@oleg> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1058 Lines: 29 sched_setscheduler() looks at ->signal->rlim[]. It is unsafe do dereference ->signal unless tasklist_lock or ->siglock is held (or p == current). We pin the task structure, but this can't prevent from release_task()->__exit_signal() which sets ->signal = NULL. Restore tasklist_lock across the setscheduler call. Signed-off-by: Oleg Nesterov --- 2.6.18-rc4/kernel/sched.c~1_revert 2006-08-19 17:50:56.000000000 +0400 +++ 2.6.18-rc4/kernel/sched.c 2006-08-19 18:15:15.000000000 +0400 @@ -4162,10 +4162,8 @@ do_sched_setscheduler(pid_t pid, int pol read_unlock_irq(&tasklist_lock); return -ESRCH; } - get_task_struct(p); - read_unlock_irq(&tasklist_lock); retval = sched_setscheduler(p, policy, &lparam); - put_task_struct(p); + read_unlock_irq(&tasklist_lock); return retval; } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/