linux-kernel - Re: [PATCH for 3.2.34] memcg: do not trigger OOM from add_to_page_cache

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20121206012924.FE077FD7@pobox.sk>
Date:	Thu, 06 Dec 2012 01:29:24 +0100
From:	"azurIt" <azurit@...ox.sk>
To:	Michal Hocko <mhocko@...e.cz>
Cc:	<linux-kernel@...r.kernel.org>, <linux-mm@...ck.org>,
	cgroups mailinglist <cgroups@...r.kernel.org>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Johannes Weiner <hannes@...xchg.org>
Subject: Re: [PATCH for 3.2.34] memcg: do not trigger OOM from add_to_page_cache_locked

>OK, so the ENOMEM seems to be leaking from mem_cgroup_newpage_charge.
>This can only happen if this was an atomic allocation request
>(!__GFP_WAIT) or if oom is not allowed which is the case only for
>transparent huge page allocation.
>The first case can be excluded (in the clean 3.2 stable kernel) because
>all callers of mem_cgroup_newpage_charge use GFP_KERNEL. The later one
>should be OK because the page fault should fallback to a regular page if
>THP allocation/charge fails.
>[/me goes to double check]
>Hmm do_huge_pmd_wp_page seems to charge a huge page and fails with
>VM_FAULT_OOM without any fallback. We should do_huge_pmd_wp_page_fallback
>instead. This has been fixed in 3.5-rc1 by 1f1d06c3 (thp, memcg: split
>hugepage for memcg oom on cow) but it hasn't been backported to 3.2. The
>patch applies to 3.2 without any further modifications. I didn't have
>time to test it but if it helps you we should push this to the stable
>tree.


This, unfortunately, didn't fix the problem :(
http://www.watchdog.sk/lkml/oom_mysqld3
--
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/