linux-kernel - Re: [PATCH] memcg: fix Bad page state after replace_page

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: <4F90C01E.3040909@jp.fujitsu.com>
Date:	Fri, 20 Apr 2012 10:47:10 +0900
From:	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
To:	Hugh Dickins <hughd@...gle.com>
CC:	Linus Torvalds <torvalds@...ux-foundation.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Miklos Szeredi <mszeredi@...e.cz>,
	Johannes Weiner <hannes@...xchg.org>,
	Michal Hocko <mhocko@...e.cz>, linux-kernel@...r.kernel.org,
	linux-mm@...ck.org
Subject: Re: [PATCH] memcg: fix Bad page state after replace_page_cache

(2012/04/19 15:34), Hugh Dickins wrote:

> My 9ce70c0240d0 "memcg: fix deadlock by inverting lrucare nesting" put a
> nasty little bug into v3.3's version of mem_cgroup_replace_page_cache(),
> sometimes used for FUSE.  Replacing __mem_cgroup_commit_charge_lrucare()
> by __mem_cgroup_commit_charge(), I used the "pc" pointer set up earlier:
> but it's for oldpage, and needs now to be for newpage.  Once oldpage was
> freed, its PageCgroupUsed bit (cleared above but set again here) caused
> "Bad page state" messages - and perhaps worse, being missed from newpage.
> (I didn't find this by using FUSE, but in reusing the function for tmpfs.)
> 
> Signed-off-by: Hugh Dickins <hughd@...gle.com>
> Cc: stable@...r.kernel.org [v3.3 only]


Thanks,
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>


> ---
> 
>  mm/memcontrol.c |    1 +
>  1 file changed, 1 insertion(+)
> 
> --- 3.4-rc3/mm/memcontrol.c	2012-04-15 20:47:37.151777506 -0700
> +++ linux/mm/memcontrol.c	2012-04-18 22:29:18.490639511 -0700
> @@ -3392,6 +3392,7 @@ void mem_cgroup_replace_page_cache(struc
>  	 * the newpage may be on LRU(or pagevec for LRU) already. We lock
>  	 * LRU while we overwrite pc->mem_cgroup.
>  	 */
> +	pc = lookup_page_cgroup(newpage);
>  	__mem_cgroup_commit_charge(memcg, newpage, 1, pc, type, true);
>  }
>  
> 
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@...ck.org.  For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
> Don't email: <a href=mailto:"dont@...ck.org"> email@...ck.org </a>
> 
> 



--
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/