| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Fri, 12 Feb 2010 12:00:59 +0000 From: Mel Gorman <mel@....ul.ie> To: Andrea Arcangeli <aarcange@...hat.com> Cc: Christoph Lameter <cl@...ux-foundation.org>, Adam Litke <agl@...ibm.com>, Avi Kivity <avi@...hat.com>, David Rientjes <rientjes@...gle.com>, KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>, Mel Gorman <mel@....ul.ie>, linux-kernel@...r.kernel.org, linux-mm@...ck.org Subject: [PATCH 12/12] mm: Check the anon_vma is still valid in rmap_walk_anon() Despite the additional locking added around rmap_walk_anon, bad references still manage to trigger on ppc64. The most likely cause is a use-after-free but it's not clear if it's due to a locking problem or something ppc64 specific. This patch somewhat works around the problem by checking the contents of the anon_vma make sense before using it but it needs reviewing by eyes familiar with the page migration code to try spot where the real problem lies. Signed-off-by: Mel Gorman <mel@....ul.ie> --- mm/rmap.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/mm/rmap.c b/mm/rmap.c index fb695d3..462ac86 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1237,6 +1237,8 @@ static int rmap_walk_anon(struct page *page, int (*rmap_one)(struct page *, anon_vma = page_anon_vma(page); if (!anon_vma) goto out_rcu_unlock; + if (!anon_vma->head.next) + goto out_rcu_unlock; spin_lock(&anon_vma->lock); /* -- 1.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists