Oops: general protection fault, probably for non-canonical address 0xdffffc0000000011: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f]
CPU: 0 UID: 0 PID: 6211 Comm: syz.4.43 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:snd_usbmidi_do_output+0x199/0x560 sound/usb/midi.c:310
Code: 5c 24 48 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 88 8b ec f8 48 8b 1b 4c 8d ab 88 00 00 00 4d 89 ef 49 c1 ef 03 <43> 0f b6 04 37 84 c0 0f 85 44 02 00 00 41 c7 45 00 00 00 00 00 48
RSP: 0018:ffffc90000007ab8 EFLAGS: 00010006
RAX: 1ffff110095c1601 RBX: 0000000000000000 RCX: ffff8880254b3c00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f34 R12: 0000000000000001
R13: 0000000000000088 R14: dffffc0000000000 R15: 0000000000000011
FS: 00007fabe87816c0(0000) GS:ffff888125c13000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33063fff CR3: 0000000066ef0000 CR4: 00000000003526f0
Call Trace:
snd_usbmidi_error_timer+0x316/0x660 sound/usb/midi.c:362
call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1747
expire_timers kernel/time/timer.c:1798 [inline]
__run_timers kernel/time/timer.c:2372 [inline]
__run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
run_timer_base kernel/time/timer.c:2393 [inline]
run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
handle_softirqs+0x283/0x870 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__raw_write_unlock_irq include/linux/rwlock_api_smp.h:274 [inline]
RIP: 0010:_raw_write_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:358
Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 aa 73 20 f6 48 89 df e8 e2 13 21 f6 e8 2d 5c 4a f6 fb bf 01 00 00 00 d2 02 13 f6 65 8b 05 5b d5 23 07 85 c0 74 07 5b e9 41 41 00 00
RSP: 0018:ffffc90003b9f250 EFLAGS: 00000282
RAX: d07b6aa66c4f9600 RBX: ffff88802ecdb898 RCX: d07b6aa66c4f9600
RDX: 0000000000000006 RSI: ffffffff8d9ba2fc RDI: 0000000000000001
RBP: ffff88802ecdc050 R08: ffffffff8fa3a737 R09: 1ffffffff1f474e6
R10: dffffc0000000000 R11: fffffbfff1f474e7 R12: ffff888076946850
R13: 0000000000000001 R14: ffff88802ecdb8d8 R15: ffff88802ecdb898
class_write_lock_irq_destructor include/linux/spinlock.h:610 [inline]
snd_seq_create_port+0x5d9/0x7c0 sound/core/seq/seq_ports.c:165
snd_seq_ioctl_create_port+0x2a4/0x950 sound/core/seq/seq_clientmgr.c:1365
create_port sound/core/seq/oss/seq_oss_init.c:315 [inline]
snd_seq_oss_open+0x545/0xea0 sound/core/seq/oss/seq_oss_init.c:202
odev_open+0x67/0xa0 sound/core/seq/oss/seq_oss.c:128
chrdev_open+0x4c9/0x5e0 fs/char_dev.c:414
do_dentry_open+0x950/0x13f0 fs/open.c:965
vfs_open+0x3b/0x340 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4046
do_filp_open+0x1fa/0x410 fs/namei.c:4073
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fabe798ec29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fabe8781038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fabe7bd5fa0 RCX: 00007fabe798ec29
RDX: 0000000000181c82 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007fabe7a11e41 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000bf00 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fabe7bd6038 R14: 00007fabe7bd5fa0 R15: 00007ffdbcfe8978
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:snd_usbmidi_do_output+0x199/0x560 sound/usb/midi.c:310
Code: 5c 24 48 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 88 8b ec f8 48 8b 1b 4c 8d ab 88 00 00 00 4d 89 ef 49 c1 ef 03 <43> 0f b6 04 37 84 c0 0f 85 44 02 00 00 41 c7 45 00 00 00 00 00 48
RSP: 0018:ffffc90000007ab8 EFLAGS: 00010006
RAX: 1ffff110095c1601 RBX: 0000000000000000 RCX: ffff8880254b3c00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f34 R12: 0000000000000001
R13: 0000000000000088 R14: dffffc0000000000 R15: 0000000000000011
FS: 00007fabe87816c0(0000) GS:ffff888125c13000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33063fff CR3: 0000000066ef0000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: 5c pop %rsp
1: 24 48 and $0x48,%al
3: 48 89 d8 mov %rbx,%rax
6: 48 c1 e8 03 shr $0x3,%rax
a: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1)
f: 74 08 je 0x19
11: 48 89 df mov %rbx,%rdi
14: e8 88 8b ec f8 call 0xf8ec8ba1
19: 48 8b 1b mov (%rbx),%rbx
1c: 4c 8d ab 88 00 00 00 lea 0x88(%rbx),%r13
23: 4d 89 ef mov %r13,%r15
26: 49 c1 ef 03 shr $0x3,%r15
* 2a: 43 0f b6 04 37 movzbl (%r15,%r14,1),%eax <-- trapping instruction
2f: 84 c0 test %al,%al
31: 0f 85 44 02 00 00 jne 0x27b
37: 41 c7 45 00 00 00 00 movl $0x0,0x0(%r13)
3e: 00
3f: 48 rex.W