[PATCH -next] ALSA: pcm: fix undefined behavior in bit shift for SNDRV_PCM_RATE_KNOT

[Baisong Zhong]

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@xxxxxxxxxx>
---
 include/sound/pcm.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index 7b1a022910e8..ec28c2ec89de 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -123,7 +123,7 @@ struct snd_pcm_ops {
 #define SNDRV_PCM_RATE_384000		(1<<14)		/* 384000Hz */
 
 #define SNDRV_PCM_RATE_CONTINUOUS	(1<<30)		/* continuous range */
-#define SNDRV_PCM_RATE_KNOT		(1<<31)		/* supports more non-continuos rates */
+#define SNDRV_PCM_RATE_KNOT		(1U<<31)	/* supports more non-continuos rates */
 
 #define SNDRV_PCM_RATE_8000_44100	(SNDRV_PCM_RATE_8000|SNDRV_PCM_RATE_11025|\
 					 SNDRV_PCM_RATE_16000|SNDRV_PCM_RATE_22050|\
-- 
2.17.1