Oops: general protection fault, probably for non-canonical address 0xdffffc0000000048: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000240-0x0000000000000247]
CPU: 0 UID: 0 PID: 19388 Comm: syz.7.3893 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:snd_pcm_do_stop sound/core/pcm_native.c:1536 [inline]
RIP: 0010:snd_pcm_action_single sound/core/pcm_native.c:1315 [inline]
RIP: 0010:snd_pcm_action sound/core/pcm_native.c:1398 [inline]
RIP: 0010:snd_pcm_stop+0x2ca/0x550 sound/core/pcm_native.c:1571
Code: f6 2e 2e 2e 41 ff d3 48 8b 04 24 42 80 3c 28 00 74 08 4c 89 f7 e8 b6 f8 79 f9 41 bf 40 02 00 00 4d 03 3e 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 36 02 00 00 41 c6 07 01 48 8b 04 24 42
RSP: 0018:ffffc900041176c8 EFLAGS: 00010206
RAX: 0000000000000048 RBX: ffff888031eba000 RCX: 0000000000080000
RDX: ffffc900175e0000 RSI: 000000000000034b RDI: 000000000000034c
RBP: 0000000000000005 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed10039dd7a6 R12: ffff88802b923008
R13: dffffc0000000000 R14: ffff888031eba0c0 R15: 0000000000000240
FS:  00007f02ab4216c0(0000) GS:ffff88812633c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000004000 CR3: 000000003a2fc000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 loopback_check_format sound/drivers/aloop.c:400 [inline]
 loopback_trigger+0x1240/0x1d50 sound/drivers/aloop.c:421
 snd_pcm_do_start sound/core/pcm_native.c:1459 [inline]
 snd_pcm_action_single sound/core/pcm_native.c:1315 [inline]
 snd_pcm_action sound/core/pcm_native.c:1398 [inline]
 snd_pcm_start+0x43d/0x5d0 sound/core/pcm_native.c:1506
 __snd_pcm_lib_xfer+0x175a/0x1d10 sound/core/pcm_lib.c:2405
 snd_pcm_oss_write3+0x1bc/0x350 sound/core/oss/pcm_oss.c:1245
 snd_pcm_plug_write_transfer+0x2d1/0x4d0 sound/core/oss/pcm_plugin.c:615
 snd_pcm_oss_write2+0x283/0x440 sound/core/oss/pcm_oss.c:1377
 snd_pcm_oss_write1 sound/core/oss/pcm_oss.c:1443 [inline]
 snd_pcm_oss_write+0x6d1/0xbe0 sound/core/oss/pcm_oss.c:2799
 vfs_write+0x2a3/0xba0 fs/read_write.c:686
 ksys_write+0x156/0x270 fs/read_write.c:740
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f02ad62c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f02ab421028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f02ad8a6270 RCX: 00007f02ad62c799
RDX: 0000000000004000 RSI: 00002000000012c0 RDI: 0000000000000006
RBP: 00007f02ad6c2c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f02ad8a6308 R14: 00007f02ad8a6270 R15: 00007fff87de2b38
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:snd_pcm_do_stop sound/core/pcm_native.c:1536 [inline]
RIP: 0010:snd_pcm_action_single sound/core/pcm_native.c:1315 [inline]
RIP: 0010:snd_pcm_action sound/core/pcm_native.c:1398 [inline]
RIP: 0010:snd_pcm_stop+0x2ca/0x550 sound/core/pcm_native.c:1571
Code: f6 2e 2e 2e 41 ff d3 48 8b 04 24 42 80 3c 28 00 74 08 4c 89 f7 e8 b6 f8 79 f9 41 bf 40 02 00 00 4d 03 3e 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 36 02 00 00 41 c6 07 01 48 8b 04 24 42
RSP: 0018:ffffc900041176c8 EFLAGS: 00010206
RAX: 0000000000000048 RBX: ffff888031eba000 RCX: 0000000000080000
RDX: ffffc900175e0000 RSI: 000000000000034b RDI: 000000000000034c
RBP: 0000000000000005 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed10039dd7a6 R12: ffff88802b923008
R13: dffffc0000000000 R14: ffff888031eba0c0 R15: 0000000000000240
FS:  00007f02ab4216c0(0000) GS:ffff88812633c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000004000 CR3: 000000003a2fc000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	f6 2e                	imulb  (%rsi)
   2:	2e 2e 41 ff d3       	cs cs call *%r11
   7:	48 8b 04 24          	mov    (%rsp),%rax
   b:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1)
  10:	74 08                	je     0x1a
  12:	4c 89 f7             	mov    %r14,%rdi
  15:	e8 b6 f8 79 f9       	call   0xf979f8d0
  1a:	41 bf 40 02 00 00    	mov    $0x240,%r15d
  20:	4d 03 3e             	add    (%r14),%r15
  23:	4c 89 f8             	mov    %r15,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 36 02 00 00    	jne    0x26d
  37:	41 c6 07 01          	movb   $0x1,(%r15)
  3b:	48 8b 04 24          	mov    (%rsp),%rax
  3f:	42                   	rex.X