ALSA: pcm: fix undefined behavior in bit shift for SNDRV_PCM_RATE_KNOT
authorBaisong Zhong <zhongbaisong@huawei.com>
Mon, 21 Nov 2022 11:00:44 +0000 (19:00 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 31 Dec 2022 12:32:14 +0000 (13:32 +0100)
commit2b951e13bd17dcab98608ce9e10304ece84db3a1
tree7189b0fab64f47a589b31b0c2f19d553636ff0f7
parentbfa34e24ced68067af77acd5c3b91cd6c1d0c3c4
ALSA: pcm: fix undefined behavior in bit shift for SNDRV_PCM_RATE_KNOT

[ Upstream commit b5172e62458f8e6ff359e5f096044a488db90ac5 ]

Shifting signed 32-bit value by 31 bits is undefined, so changing
significant bit to unsigned. The UBSAN warning calltrace like below:

UBSAN: shift-out-of-bounds in sound/core/pcm_native.c:2676:21
left shift of 1 by 31 places cannot be represented in type 'int'
...
Call Trace:
 <TASK>
 dump_stack_lvl+0x8d/0xcf
 ubsan_epilogue+0xa/0x44
 __ubsan_handle_shift_out_of_bounds+0x1e7/0x208
 snd_pcm_open_substream+0x9f0/0xa90
 snd_pcm_oss_open.part.26+0x313/0x670
 snd_pcm_oss_open+0x30/0x40
 soundcore_open+0x18b/0x2e0
 chrdev_open+0xe2/0x270
 do_dentry_open+0x2f7/0x620
 path_openat+0xd66/0xe70
 do_filp_open+0xe3/0x170
 do_sys_openat2+0x357/0x4a0
 do_sys_open+0x87/0xd0
 do_syscall_64+0x34/0x80

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Baisong Zhong <zhongbaisong@huawei.com>
Link: https://lore.kernel.org/r/20221121110044.3115686-1-zhongbaisong@huawei.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
include/sound/pcm.h