From: Takashi Iwai <tiwai@suse.de>
To: Junrui Luo <moonafterrain@outlook.com>
Cc: Clemens Ladisch <clemens@ladisch.de>,
Takashi Sakamoto <o-takashi@sakamocchi.jp>,
Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
Takashi Iwai <tiwai@suse.de>,
linux-sound@vger.kernel.org, linux-kernel@vger.kernel.org,
Yuhao Jiang <danisjiang@gmail.com>
Subject: Re: [PATCH] ALSA: firewire-motu: fix buffer overflow in hwdep read for DSP events
Date: Fri, 05 Dec 2025 15:27:50 +0100 [thread overview]
Message-ID: <87qzt9vw9l.wl-tiwai@suse.de> (raw)
In-Reply-To: <SYBPR01MB78810656377E79E58350D951AFD9A@SYBPR01MB7881.ausprd01.prod.outlook.com>
On Wed, 03 Dec 2025 05:27:03 +0100,
Junrui Luo wrote:
>
> The DSP event handling code in hwdep_read() could write more bytes to
> the user buffer than requested, when a user provides a buffer smaller
> than the event header size (8 bytes).
>
> Fix by using min_t() to clamp the copy size, This ensures we never copy
> more than the user requested.
>
> Reported-by: Yuhao Jiang <danisjiang@gmail.com>
> Reported-by: Junrui Luo <moonafterrain@outlook.com>
> Fixes: 634ec0b2906e ("ALSA: firewire-motu: notify event for parameter change in register DSP model")
> Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Applied now. Thanks.
BTW, the code there has another bug; the loop of put_user() above your
change doesn't check whether it has an enough remaining size. When
count isn't aligned with 4 bytes, it might cause a similar overwrite.
It has to be corrected, too.
Takashi
prev parent reply other threads:[~2025-12-05 14:27 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-03 4:27 [PATCH] ALSA: firewire-motu: fix buffer overflow in hwdep read for DSP events Junrui Luo
2025-12-05 14:27 ` Takashi Iwai [this message]
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