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: <1314013658.2307.21.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC>
Date:	Mon, 22 Aug 2011 13:47:38 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Sathya Perla <sathya.perla@...lex.com>
Cc:	netdev@...r.kernel.org
Subject: Re: [PATCH net-next 3/5] be2net: fix erx->rx_drops_no_frags wrap
 around

Le lundi 22 août 2011 à 13:43 +0200, Eric Dumazet a écrit :

> This adds a race for lockless SNMP readers (in be_get_stats64())
> 
> They can see the 32bit value going backward.
> 
> You have to be very careful to read the *acc once, and write it once.

The "write once" is the only requirement.

Something like :

u32 newval = hi(*acc) + val;

if (wrapped)
	newval += 65536;
ACCESS_ONCE(*acc) = newval;



--
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

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ