From: Zubin Mithra <zsm@chromium.org>
Date: Fri, 27 Aug 2021 15:37:35 +0000 (-0700)
Subject: ALSA: pcm: fix divide error in snd_pcm_lib_ioctl
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4a62351ee6ba07508a3b948bc30d5c9396930b77;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

ALSA: pcm: fix divide error in snd_pcm_lib_ioctl

commit f3eef46f0518a2b32ca1244015820c35a22cfe4a upstream.

Syzkaller reported a divide error in snd_pcm_lib_ioctl. fifo_size
is of type snd_pcm_uframes_t(unsigned long). If frame_size
is 0x100000000, the error occurs.

Fixes: a9960e6a293e ("ALSA: pcm: fix fifo_size frame calculation")
Signed-off-by: Zubin Mithra <zsm@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210827153735.789452-1-zsm@chromium.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index c412f2a909c9..82a7387ba9d2 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -1757,7 +1757,7 @@ static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
 		channels = params_channels(params);
 		frame_size = snd_pcm_format_size(format, channels);
 		if (frame_size > 0)
-			params->fifo_size /= (unsigned)frame_size;
+			params->fifo_size /= frame_size;
 	}
 	return 0;
 }