ALSA: seq: fix undefined behavior in bit shift for SNDRV_SEQ_FILTER_USE_EVENT

[ Upstream commit cf59e1e4c79bf741905484cdb13c130b53576a16 ]

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/seq/seq_clientmgr.c:509:22
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_seq_deliver_single_event.constprop.21+0x191/0x2f0
 snd_seq_deliver_event+0x1a2/0x350
 snd_seq_kernel_client_dispatch+0x8b/0xb0
 snd_seq_client_notify_subscription+0x72/0xa0
 snd_seq_ioctl_subscribe_port+0x128/0x160
 snd_seq_kernel_client_ctl+0xce/0xf0
 snd_seq_oss_create_client+0x109/0x15b
 alsa_seq_oss_init+0x11c/0x1aa
 do_one_initcall+0x80/0x440
 kernel_init_freeable+0x370/0x3c3
 kernel_init+0x1b/0x190
 ret_from_fork+0x1f/0x30
 </TASK>

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Baisong Zhong <zhongbaisong@huawei.com>
Link: https://lore.kernel.org/r/20221121111630.3119259-1-zhongbaisong@huawei.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/include/uapi/sound/asequencer.h b/include/uapi/sound/asequencer.h
index a75e14e..dbd60f4 100644 (file)
--- a/include/uapi/sound/asequencer.h
+++ b/include/uapi/sound/asequencer.h
@@ -344,10 +344,10 @@ typedef int __bitwise snd_seq_client_type_t;
 #define        KERNEL_CLIENT   ((__force snd_seq_client_type_t) 2)
                         
        /* event filter flags */
-#define SNDRV_SEQ_FILTER_BROADCAST     (1<<0)  /* accept broadcast messages */
-#define SNDRV_SEQ_FILTER_MULTICAST     (1<<1)  /* accept multicast messages */
-#define SNDRV_SEQ_FILTER_BOUNCE                (1<<2)  /* accept bounce event in error */
-#define SNDRV_SEQ_FILTER_USE_EVENT     (1<<31) /* use event filter */
+#define SNDRV_SEQ_FILTER_BROADCAST     (1U<<0) /* accept broadcast messages */
+#define SNDRV_SEQ_FILTER_MULTICAST     (1U<<1) /* accept multicast messages */
+#define SNDRV_SEQ_FILTER_BOUNCE                (1U<<2) /* accept bounce event in error */
+#define SNDRV_SEQ_FILTER_USE_EVENT     (1U<<31)        /* use event filter */
 
 struct snd_seq_client_info {
        int client;                     /* client number to inquire */