linux-kernel - Re: [Bug #16626] Machine hangs with EIP at skb_copy_and_csum

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: <20100901.182318.191170819.davem@davemloft.net>
Date:	Wed, 01 Sep 2010 18:23:18 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	eric.dumazet@...il.com
Cc:	jarkao2@...il.com, pvp-lsts@...uni-ruse.bg,
	herbert@...dor.apana.org.au, rjw@...k.pl,
	kernel-testers@...r.kernel.org, maciej.rutecki@...il.com,
	linux-kernel@...r.kernel.org, netdev@...r.kernel.org
Subject: Re: [Bug #16626] Machine hangs with EIP at skb_copy_and_csum_dev

From: Eric Dumazet <eric.dumazet@...il.com>
Date: Wed, 01 Sep 2010 12:50:51 +0200

> [PATCH] gro: fix different skb headrooms
> 
> packets entering GRO might have different headrooms, even for a given
> flow (because of implementation details in drivers, like copybreak).
> We cant force drivers to deliver packets with a fixed headroom.
> 
> 1) fix skb_segment()
> 
> skb_segment() makes the false assumption headrooms of fragments are same
> than the head. When CHECKSUM_PARTIAL is used, this can give csum_start
> errors, and crash later in skb_copy_and_csum_dev()
> 
> 2) allocate a minimal skb for head of frag_list
> 
> skb_gro_receive() uses netdev_alloc_skb(headroom + skb_gro_offset(p)) to
> allocate a fresh skb. This adds NET_SKB_PAD to a padding already
> provided by netdevice, depending on various things, like copybreak.
> 
> Use alloc_skb() to allocate an exact padding, to reduce cache line
> needs:
> NET_SKB_PAD + NET_IP_ALIGN
> 
> bugzilla : https://bugzilla.kernel.org/show_bug.cgi?id=16626
> 
> Many thanks to Plamen Petrov, testing many debugging patches !
> With help of Jarek Poplawski.
> 
> Reported-by: Plamen Petrov <pvp-lsts@...uni-ruse.bg>
> Signed-off-by: Eric Dumazet <eric.dumazet@...il.com>
> CC: Jarek Poplawski <jarkao2@...il.com>

Good spotting, applied, thanks!
--
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/