ALSA: pcm: fix divide error in snd_pcm_lib_ioctl

stable inclusion
from stable-5.10.63
commit 8e41134a92a50a11ecf7823bc1a19a4dd347463a
bugzilla: 182231 https://gitee.com/openeuler/kernel/issues/I4EFS1

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8e41134a92a50a11ecf7823bc1a19a4dd347463a

--------------------------------

commit f3eef46f 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: a9960e6a ("ALSA: pcm: fix fifo_size frame calculation")
Signed-off-by: NZubin Mithra <zsm@chromium.org>
Reviewed-by: NGuenter Roeck <groeck@chromium.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210827153735.789452-1-zsm@chromium.orgSigned-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

sound/core/pcm_lib.c

@@ -1746,7 +1746,7 @@ 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;
 }