From mboxrd@z Thu Jan 1 00:00:00 1970 From: Liang Li Subject: Re: [Bug #15615] NULL pointer deref in task_is_waking Date: Thu, 8 Apr 2010 15:16:17 +0800 Message-ID: <20100408071617.GC26543@localhost> References: <6Pphclm24fK.A.lSF.qsPvLB@chimera> Reply-To: Liang Li Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: Sender: kernel-testers-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "Rafael J. Wysocki" Cc: Linux Kernel Mailing List , Kernel Testers List , Maciej Rutecki , Amit Shah On Wed, Apr 07, 2010 at 11:13:48PM +0200, Rafael J. Wysocki wrote: > This message has been generated automatically as a part of a summary report > of recent regressions. > > The following bug entry is on the current list of known regressions > from 2.6.33. Please verify if it still should be listed and let the tracking team > know (either way). The bug still there. I just met it. And seems its quite simple to get it fixed. diff --git a/kernel/sched.c b/kernel/sched.c index a3dff1f..2df1a76 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -913,7 +913,7 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) */ static inline int task_is_waking(struct task_struct *p) { - return unlikely((p->state == TASK_WAKING) && !(p->flags & PF_STARTING)); + return unlikely(p && (p->state == TASK_WAKING) && !(p->flags & PF_STARTING)); } /* But seems commitid 0017d735092844118bef006696a750a0e4ef6ebd in tip tree also touched task_is_waking. So the patch for tip tree should be: diff --git a/kernel/sched.c b/kernel/sched.c index 3acf694..d259641 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -920,7 +920,7 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) */ static inline int task_is_waking(struct task_struct *p) { - return unlikely(p->state == TASK_WAKING); + return unlikely(p && p->state == TASK_WAKING); } /* Regards, -Liang Li > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=15615 > Subject : NULL pointer deref in task_is_waking > Submitter : Amit Shah > Date : 2010-03-23 04:04 (16 days old) > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/