linux-kernel - Re: [PATCH] ALSA: hda - Handle kzalloc() failure in snd_hda_attach_pcm

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] [day] [month] [year] [list]

Message-ID: <s5hzi0f3qha.wl-tiwai@suse.de>
Date:   Fri, 01 Jun 2018 09:39:29 +0200
From:   Takashi Iwai <tiwai@...e.de>
To:     "Bo Chen" <chenbo@....edu>
Cc:     <alsa-devel@...a-project.org>, <perex@...ex.cz>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] ALSA: hda - Handle kzalloc() failure in snd_hda_attach_pcm_stream()

On Fri, 01 Jun 2018 00:35:18 +0200,
Bo Chen wrote:
> 
> When 'kzalloc()' fails in 'snd_hda_attach_pcm_stream()', a new pcm instance is
> created without setting its operators via 'snd_pcm_set_ops()'. Following
> operations on the new pcm instance can trigger kernel null pointer dereferences
> and cause kernel oops.
> 
> This bug was found with my work on building a gray-box fault-injection tool for
> linux-kernel-module binaries. A kernel null pointer dereference was confirmed
> from line 'substream->ops->open()' in function 'snd_pcm_open_substream()' in
> file 'sound/core/pcm_native.c'.
> 
> This patch fixes the bug by calling 'snd_device_free()' in the error handling
> path of 'kzalloc()', which removes the new pcm instance from the snd card before
> returns with an error code.
> 
> Signed-off-by: Bo Chen <chenbo@....edu>

Applied now.  Thanks.


Takashi