From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Hocko Subject: [PATCH] hugetlb: release pages in the error path of hugetlb_cow() (was: Re: 3.2-rc2+: Reported regressions from 3.0 and 3.1) Date: Mon, 28 Nov 2011 09:33:13 +0100 Message-ID: <20111128083313.GA18337@tiehlicka.suse.cz> References: <201111212249.31196.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: Sender: kernel-testers-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: "Rafael J. Wysocki" , Andy Lutomirski , Linux Kernel Mailing List , Maciej Rutecki , Florian Mickler , Andrew Morton , Kernel Testers List , Network Development , Linux ACPI , Linux PM List , Linux SCSI List , Linux Wireless List , DRI , Linus Torvalds List-Id: dri-devel@lists.freedesktop.org On Mon 21-11-11 14:18:29, Linus Torvalds wrote: > On Mon, Nov 21, 2011 at 1:49 PM, Rafael J. Wysocki wrot= e: > > > > Subject =A0 =A0: hugetlb oops on 3.1.0-rc8-devel > > Submitter =A0: Andy Lutomirski > > Date =A0 =A0 =A0 : 2011-11-01 22:20 > > Message-ID : CALCETrW1mpVCz2tO5roaz1r6vnno+srHR-dHA6_pkRi2qiCfdw@ma= il.gmail.com > > References : http://marc.info/?l=3Dlinux-kernel&m=3D132018604426692= &w=3D2 >=20 > Despite the subject line, that's not an oops, it's a BUG_ON(). >=20 > And it *should* be fixed by commit ea4039a34c4c ("hugetlb: release > pages in the error path of hugetlb_cow()") although I don't think And= y > ever confirmed that (since it was hard to trigger). AFAICS the issue has been introduced by 0fe6e20b (hugetlb, rmap: add reverse mapping for hugepage) in 2.6.36-rc1 so this is a stable material. I do not see the patch in any stable branch so here we go. The patch is on top of 3.0.y branch and it applies as is to 3.1.y as well. --- =46rom fdaa4aaa008cce149a5fd60934112acd8988e0b6 Mon Sep 17 00:00:00 200= 1 =46rom: Hillf Danton Date: Tue, 15 Nov 2011 14:36:12 -0800 Subject: [PATCH] hugetlb: release pages in the error path of hugetlb_co= w() commit ea4039a34c4c206d015d34a49d0b00868e37db1d upstream. If we fail to prepare an anon_vma, the {new, old}_page should be releas= ed, or they will leak. Signed-off-by: Hillf Danton Reviewed-by: Andrea Arcangeli Cc: Hugh Dickins Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hugetlb.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index bfcf153..2b57cd9 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2415,6 +2415,8 @@ retry_avoidcopy: * anon_vma prepared. */ if (unlikely(anon_vma_prepare(vma))) { + page_cache_release(new_page); + page_cache_release(old_page); /* Caller expects lock to be held */ spin_lock(&mm->page_table_lock); return VM_FAULT_OOM; --=20 1.7.7.3 --=20 Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 =20 Czech Republic