netdev - Re: [PATCH v2] net, socket, socket_wq: fix missing initialization of flags

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

Message-Id: <20151230.163915.990334768673899184.davem@davemloft.net>
Date:	Wed, 30 Dec 2015 16:39:15 -0500 (EST)
From:	David Miller <davem@...emloft.net>
To:	nicstange@...il.com
Cc:	edumazet@...gle.com, netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] net, socket, socket_wq: fix missing initialization
 of flags

From: Nicolai Stange <nicstange@...il.com>
Date: Tue, 29 Dec 2015 13:29:55 +0100

> Fixes: ceb5d58b2170 ("net: fix sock_wake_async() rcu protection")
> 
> Commit ceb5d58b2170 ("net: fix sock_wake_async() rcu protection") from
> the current 4.4 release cycle introduced a new flags member in
> struct socket_wq and moved SOCKWQ_ASYNC_NOSPACE and SOCKWQ_ASYNC_WAITDATA
> from struct socket's flags member into that new place.
> 
> Unfortunately, the new flags field is never initialized properly, at least
> not for the struct socket_wq instance created in sock_alloc_inode().
> 
> One particular issue I encountered because of this is that my GNU Emacs
> failed to draw anything on my desktop -- i.e. what I got is a transparent
> window, including the title bar. Bisection lead to the commit mentioned
> above and further investigation by means of strace told me that Emacs
> is indeed speaking to my Xorg through an O_ASYNC AF_UNIX socket. This is
> reproducible 100% of times and the fact that properly initializing the
> struct socket_wq ->flags fixes the issue leads me to the conclusion that
> somehow SOCKWQ_ASYNC_WAITDATA got set in the uninitialized ->flags,
> preventing my Emacs from receiving any SIGIO's due to data becoming
> available and it got stuck.
> 
> Make sock_alloc_inode() set the newly created struct socket_wq's ->flags
> member to zero.
> 
> Signed-off-by: Nicolai Stange <nicstange@...il.com>

Applied, but please in the future please put the Fixes: tag right
above the first signoff/ack, like this:

Fixes: ceb5d58b2170 ("net: fix sock_wake_async() rcu protection")
Signed-off-by: Nicolai Stange <nicstange@...il.com>
--
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