netdev - xt_hashlimit.c race?

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-next>] [day] [month] [year] [list]

Message-Id: <20201347974535@web11g.yandex.ru>
Date:	Tue, 18 Sep 2012 17:22:15 +0400
From:	"\"Oleg A. Arkhangelsky\"" <sysoleg@...dex.ru>
To:	netdev@...r.kernel.org
Subject: xt_hashlimit.c race?

Hello,

Looking at the net/netfilter/xt_hashlimit.c revealed one question. As far as
I can understand hashlimit_mt() code under rcu_read_lock_bh() can be
executed simultaneously by more than one CPU. So what if we have two
packets with the same new dst value that processed in parallel by different
CPUs? In both cases dh is NULL and both CPUs tries to create new
entry in hash table. This is not what we want and can lead to undefined
behavior in the future.

Or maybe I'm wrong? Could anyone tell me is this situation possible?

Thank you!

-- 
wbr, Oleg.
--
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