netdev - Re: [PATCH net-next 1/2] net: neighbour: prohibit negative value for unres_qlen

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 for Android: free password hash cracker in your pocket

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

Message-Id: <20121205.162605.1922207208186317600.davem@davemloft.net>
Date:	Wed, 05 Dec 2012 16:26:05 -0500 (EST)
From:	David Miller <davem@...emloft.net>
To:	shanwei88@...il.com
Cc:	eric.dumazet@...il.com, netdev@...r.kernel.org
Subject: Re: [PATCH net-next 1/2] net: neighbour: prohibit negative value
 for unres_qlen_bytes parameter

From: Shan Wei <shanwei88@...il.com>
Date: Wed, 05 Dec 2012 12:49:15 +0800

> From: Shan Wei <davidshan@...cent.com>
> 
> unres_qlen_bytes and unres_qlen are int type.
> But multiple relation(unres_qlen_bytes = unres_qlen * SKB_TRUESIZE(ETH_FRAME_LEN))
> will cause type overflow when seting unres_qlen. e.g.
> 
> $ echo 1027506 > /proc/sys/net/ipv4/neigh/eth1/unres_qlen
> $ cat /proc/sys/net/ipv4/neigh/eth1/unres_qlen
> 1182657265
> $ cat /proc/sys/net/ipv4/neigh/eth1/unres_qlen_bytes 
> -2147479756
> 
> The gutted value is not that we setting。
> But user/administrator don't know this is caused by int type overflow.
> 
> what's more, it is meaningless and even dangerous that unres_qlen_bytes is set
> with negative number. Because, for unresolved neighbour address, kernel will cache packets
> without limit in __neigh_event_send()(e.g. (u32)-1 = 2GB).
> 
> 
> Signed-off-by: Shan Wei <davidshan@...cent.com>

Applied.
--
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