netdev - Re: [PATCH net] net: add pfmemalloc check in sk_add

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: <20150929.215607.1418732892830129304.davem@davemloft.net>
Date:	Tue, 29 Sep 2015 21:56:07 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	eric.dumazet@...il.com
Cc:	netdev@...r.kernel.org, gthelen@...gle.com, mhocko@...e.com,
	mgorman@...e.de
Subject: Re: [PATCH net] net: add pfmemalloc check in sk_add_backlog()

From: Eric Dumazet <eric.dumazet@...il.com>
Date: Tue, 29 Sep 2015 18:52:25 -0700

> From: Eric Dumazet <edumazet@...gle.com>
> 
> Greg reported crashes hitting the following check in __sk_backlog_rcv()
> 
> 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC)); 
> 
> The pfmemalloc bit is currently checked in sk_filter().
> 
> This works correctly for TCP, because sk_filter() is ran in
> tcp_v[46]_rcv() before hitting the prequeue or backlog checks.
> 
> For UDP or other protocols, this does not work, because the sk_filter()
> is ran from sock_queue_rcv_skb(), which might be called _after_ backlog
> queuing if socket is owned by user by the time packet is processed by
> softirq handler.
> 
> Fixes: b4b9e35585089 ("netvm: set PF_MEMALLOC as appropriate during SKB processing")
> Signed-off-by: Eric Dumazet <edumazet@...gle.com>
> Reported-by: Greg Thelen <gthelen@...gle.com>

Applied, thanks Eric.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html