Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 24 Aug 2022 11:42:25 +0200
Message-ID: <87ilmirn9a.wl-tiwai@suse.de>
From:   Takashi Iwai <tiwai@suse.de>
To:     Zheyu Ma <zheyuma97@gmail.com>
Cc:     Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
        alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ALSA: control: Fix an out-of-bounds bug in get_ctl_id_hash()
In-Reply-To: <20220824081654.3767739-1-zheyuma97@gmail.com>
References: <20220824081654.3767739-1-zheyuma97@gmail.com>
User-Agent: Wanderlust/2.15.9 (Almost Unreal) Emacs/27.2 Mule/6.0
MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue")
Content-Type: text/plain; charset=US-ASCII
Precedence: bulk

On Wed, 24 Aug 2022 10:16:54 +0200,
Zheyu Ma wrote:
> 
> Since the user can control the arguments provided to the kernel by the
> ioctl() system call, an out-of-bounds bug occurs when the 'id->name'
> provided by the user does not end with '\0'.
> 
> The following log can reveal it:
> 
> [    10.002313] BUG: KASAN: stack-out-of-bounds in snd_ctl_find_id+0x36c/0x3a0
> [    10.002895] Read of size 1 at addr ffff888109f5fe28 by task snd/439
> [    10.004934] Call Trace:
> [    10.007140]  snd_ctl_find_id+0x36c/0x3a0
> [    10.007489]  snd_ctl_ioctl+0x6cf/0x10e0
> 
> Fix this by checking the bound of 'id->name' in the loop.
> 
> Fixes: c27e1efb61c5 ("ALSA: control: Use xarray for faster lookups")
> Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>

Thanks, applied now.


Takashi