From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx173.postini.com [74.125.245.173]) by kanga.kvack.org (Postfix) with SMTP id 2EBC08D0001 for ; Sat, 29 Dec 2012 03:45:29 -0500 (EST) Received: by mail-qc0-f174.google.com with SMTP id o22so5867438qcr.33 for ; Sat, 29 Dec 2012 00:45:28 -0800 (PST) MIME-Version: 1.0 Reply-To: sedat.dilek@gmail.com In-Reply-To: <50DD0106.7040001@iskon.hr> References: <50D24AF3.1050809@iskon.hr> <20121220111208.GD10819@suse.de> <20121220125802.23e9b22d.akpm@linux-foundation.org> <50D601C9.9060803@iskon.hr> <50D71166.6030608@iskon.hr> <50DB129E.7010000@iskon.hr> <50DD0106.7040001@iskon.hr> Date: Sat, 29 Dec 2012 09:45:27 +0100 Message-ID: Subject: Re: [PATCH] mm: fix null pointer dereference in wait_iff_congested() From: Sedat Dilek Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Zlatko Calusic Cc: Andrew Morton , Mel Gorman , Linus Torvalds , Hugh Dickins , linux-mm , Linux Kernel Mailing List , Zhouping Liu Just FYI: This patch landed upstream [1]. Thanks for all involved people. - Sedat - [1] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=ecccd1248d6e6986130ffcc3b0d003cb46a485c0 On Fri, Dec 28, 2012 at 3:16 AM, Zlatko Calusic wrote: > From: Zlatko Calusic > > The unintended consequence of commit 4ae0a48b is that > wait_iff_congested() can now be called with NULL struct zone* > producing kernel oops like this: > > BUG: unable to handle kernel NULL pointer dereference > IP: [] wait_iff_congested+0x59/0x140 > > This trivial patch fixes it. > > Reported-by: Zhouping Liu > Reported-and-tested-by: Sedat Dilek > Cc: Andrew Morton > Cc: Mel Gorman > Cc: Hugh Dickins > Signed-off-by: Zlatko Calusic > --- > mm/vmscan.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 02bcfa3..e55ce55 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2782,7 +2782,7 @@ loop_again: > if (total_scanned && (sc.priority < DEF_PRIORITY - 2)) { > if (has_under_min_watermark_zone) > count_vm_event(KSWAPD_SKIP_CONGESTION_WAIT); > - else > + else if (unbalanced_zone) > wait_iff_congested(unbalanced_zone, BLK_RW_ASYNC, HZ/10); > } > > -- > 1.8.1.rc3 > > -- > Zlatko -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org