netdev - Re: [PATCH] sock: Fix sk_sleep return invalid pointer

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: <f80fcd476a230c354bf9758762250c43a1f3d5cc.camel@redhat.com>
Date: Tue, 22 Aug 2023 17:31:00 +0200
From: Paolo Abeni <pabeni@...hat.com>
To: eadavis@...a.com, syzbot+666c97e4686410e79649@...kaller.appspotmail.com
Cc: davem@...emloft.net, edumazet@...gle.com, kuba@...nel.org, 
 linux-hams@...r.kernel.org, linux-kernel@...r.kernel.org,
 netdev@...r.kernel.org,  ralf@...ux-mips.org,
 syzkaller-bugs@...glegroups.com, hdanton@...a.com
Subject: Re: [PATCH] sock: Fix sk_sleep return invalid pointer

On Tue, 2023-08-22 at 20:44 +0800, eadavis@...a.com wrote:
> From: Edward AD <eadavis@...a.com>
> 
> The parameter sk_sleep(sk) passed in when calling prepare_to_wait may 
> return an invalid pointer due to nr-release reclaiming the sock.
> Here, schedule_timeout_interruptible is used to replace the combination 
> of 'prepare_to_wait, schedule, finish_wait' to solve the problem.
> 
> Reported-and-tested-by: syzbot+666c97e4686410e79649@...kaller.appspotmail.com
> Signed-off-by: Edward AD <eadavis@...a.com>

This looks wrong. No syscall should race with sock_release(). It looks
like you are papering over the real issue.

As the reproducer shows a disconnect on an connected socket, I'm wild
guessing something alike 4faeee0cf8a5d88d63cdbc3bab124fb0e6aed08c
should be more appropriate.

Cheers,

Paolo