==================================================================
BUG: KASAN: use-after-free in __snd_rawmidi_transmit_peek sound/core/rawmidi.c:1286 [inline]
BUG: KASAN: use-after-free in snd_rawmidi_transmit+0x392/0x400 sound/core/rawmidi.c:1411
Read of size 1 at addr ffff88805fdfa058 by task udevd/3546
CPU: 1 PID: 3546 Comm: udevd Not tainted 5.15.182-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
<IRQ>
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
print_address_description+0x60/0x2d0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:434 [inline]
kasan_report+0xdf/0x130 mm/kasan/report.c:451
__snd_rawmidi_transmit_peek sound/core/rawmidi.c:1286 [inline]
snd_rawmidi_transmit+0x392/0x400 sound/core/rawmidi.c:1411
snd_usbmidi_standard_output+0x1e4/0xdd0 sound/usb/midi.c:718
snd_usbmidi_do_output+0x21e/0x560 sound/usb/midi.c:311
snd_usbmidi_error_timer+0x312/0x660 sound/usb/midi.c:362
call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
expire_timers kernel/time/timer.c:1496 [inline]
__run_timers+0x525/0x7c0 kernel/time/timer.c:1767
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
handle_softirqs+0x328/0x820 kernel/softirq.c:558
__do_softirq kernel/softirq.c:592 [inline]
invoke_softirq kernel/softirq.c:432 [inline]
__irq_exit_rcu+0x12f/0x220 kernel/softirq.c:641
irq_exit_rcu+0x5/0x20 kernel/softirq.c:653
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 ee 4f d3 f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> c6 cf a6 f7 65 8b 05 67 e3 57 76 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc900025dfca0 EFLAGS: 00000206
RAX: a56f1ac2083d2500 RBX: 0000000000000a06 RCX: a56f1ac2083d2500
RDX: dffffc0000000000 RSI: ffffffff8a0b0fc0 RDI: 0000000000000001
RBP: ffffc900025dfd30 R08: dffffc0000000000 R09: fffffbfff2c676f5
R10: fffffbfff2c676f5 R11: 1ffffffff2c676f4 R12: dffffc0000000000
R13: 1ffff920004bbfb8 R14: ffffffff9633b7a0 R15: 1ffff920004bbf94
debug_rcu_head_queue kernel/rcu/rcu.h:177 [inline]
__call_rcu kernel/rcu/tree.c:2991 [inline]
call_rcu+0xb7/0x920 kernel/rcu/tree.c:3087
task_work_run+0x125/0x1a0 kernel/task_work.c:188
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f755fd63a67
Code: 44 00 00 48 83 ec 10 48 63 ff 45 31 c9 45 31 c0 6a 01 31 c9 e8 ca 19 f9 ff 48 83 c4 18 c3 0f 1f 44 00 00 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 61 b3 0d 00 f7 d8 64 89 02 b8
RSP: 002b:00007fffb0b0a548 EFLAGS: 00000297 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000558cb326e190 RCX: 00007f755fd63a67
RDX: 00007f755fe3dea0 RSI: 0000558cb3308980 RDI: 000000000000000c
RBP: 00007f755fe3dff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000
R13: 3d45505954564544 R14: 3d5845444e494649 R15: 3d454d414e564544
</TASK>
Allocated by task 10105:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc mm/kasan/common.c:513 [inline]
__kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522
kmalloc_node include/linux/slab.h:627 [inline]
kvmalloc_node+0x84/0x130 mm/util.c:619
kvmalloc include/linux/mm.h:805 [inline]
kvzalloc include/linux/mm.h:813 [inline]
snd_rawmidi_runtime_create sound/core/rawmidi.c:162 [inline]
open_substream+0x29d/0x6c0 sound/core/rawmidi.c:306
rawmidi_open_priv+0xc4/0x660 sound/core/rawmidi.c:357
snd_rawmidi_kernel_open+0x1a2/0x240 sound/core/rawmidi.c:392
midisynth_use+0xd8/0x260 sound/core/seq/seq_midi.c:221
subscribe_port sound/core/seq/seq_ports.c:412 [inline]
check_and_subscribe_port+0x669/0xb30 sound/core/seq/seq_ports.c:495
snd_seq_port_connect+0x256/0x430 sound/core/seq/seq_ports.c:581
snd_seq_ioctl_subscribe_port+0x32c/0x6f0 sound/core/seq/seq_clientmgr.c:1490
snd_seq_oss_midi_open+0x3a4/0x7c0 sound/core/seq/oss/seq_oss_midi.c:365
snd_seq_oss_synth_setup_midi+0x129/0x520 sound/core/seq/oss/seq_oss_synth.c:269
snd_seq_oss_open+0x87a/0xe40 sound/core/seq/oss/seq_oss_init.c:261
odev_open+0x63/0x90 sound/core/seq/oss/seq_oss.c:128
chrdev_open+0x597/0x670 fs/char_dev.c:414
do_dentry_open+0x7ff/0xf80 fs/open.c:826
do_open fs/namei.c:3608 [inline]
path_openat+0x2682/0x2f30 fs/namei.c:3742
do_filp_open+0x1b3/0x3e0 fs/namei.c:3769
do_sys_openat2+0x142/0x4a0 fs/open.c:1253
do_sys_open fs/open.c:1269 [inline]
__do_sys_openat fs/open.c:1285 [inline]
__se_sys_openat fs/open.c:1280 [inline]
__x64_sys_openat+0x135/0x160 fs/open.c:1280
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
Freed by task 10105:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1705 [inline]
slab_free_freelist_hook+0xea/0x170 mm/slub.c:1731
slab_free mm/slub.c:3499 [inline]
kfree+0xef/0x2a0 mm/slub.c:4559
snd_rawmidi_runtime_free sound/core/rawmidi.c:176 [inline]
close_substream+0x360/0x5a0 sound/core/rawmidi.c:528
rawmidi_release_priv+0xe9/0x170 sound/core/rawmidi.c:547
snd_rawmidi_kernel_release+0x42/0xa0 sound/core/rawmidi.c:564
unsubscribe_port sound/core/seq/seq_ports.c:437 [inline]
__delete_and_unsubscribe_port+0x280/0x430 sound/core/seq/seq_ports.c:537
snd_seq_port_disconnect+0x4f5/0x620 sound/core/seq/seq_ports.c:616
snd_seq_ioctl_unsubscribe_port+0x32c/0x6f0 sound/core/seq/seq_clientmgr.c:1535
snd_seq_oss_midi_close+0x2fc/0x620 sound/core/seq/oss/seq_oss_midi.c:413
snd_seq_oss_synth_reset+0x3e9/0x960 sound/core/seq/oss/seq_oss_synth.c:406
snd_seq_oss_reset+0x56/0x240 sound/core/seq/oss/seq_oss_init.c:436
snd_seq_oss_release+0xe8/0x2c0 sound/core/seq/oss/seq_oss_init.c:413
odev_release+0x52/0x70 sound/core/seq/oss/seq_oss.c:144
__fput+0x234/0x930 fs/file_table.c:311
task_work_run+0x125/0x1a0 kernel/task_work.c:188
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
The buggy address belongs to the object at ffff88805fdfa000
which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 88 bytes inside of
4096-byte region [ffff88805fdfa000, ffff88805fdfb000)
The buggy address belongs to the page:
page:ffffea00017f7e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5fdf8
head:ffffea00017f7e00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888016842140
raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 10105, ts 724350415657, free_ts 722131021083
prep_new_page mm/page_alloc.c:2426 [inline]
get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
__alloc_pages+0x1e1/0x470 mm/page_alloc.c:5466
alloc_slab_page mm/slub.c:1775 [inline]
allocate_slab mm/slub.c:1912 [inline]
new_slab+0xc0/0x4b0 mm/slub.c:1975
___slab_alloc+0x81e/0xdf0 mm/slub.c:3008
__slab_alloc mm/slub.c:3095 [inline]
slab_alloc_node mm/slub.c:3186 [inline]
__kmalloc_node+0x200/0x3b0 mm/slub.c:4451
kmalloc_node include/linux/slab.h:627 [inline]
kvmalloc_node+0x84/0x130 mm/util.c:619
kvmalloc include/linux/mm.h:805 [inline]
kvzalloc include/linux/mm.h:813 [inline]
snd_rawmidi_runtime_create sound/core/rawmidi.c:162 [inline]
open_substream+0x29d/0x6c0 sound/core/rawmidi.c:306
rawmidi_open_priv+0x94/0x660 sound/core/rawmidi.c:352
snd_rawmidi_kernel_open+0x1a2/0x240 sound/core/rawmidi.c:392
midisynth_subscribe+0xd8/0x320 sound/core/seq/seq_midi.c:177
subscribe_port sound/core/seq/seq_ports.c:412 [inline]
check_and_subscribe_port+0x669/0xb30 sound/core/seq/seq_ports.c:495
snd_seq_port_connect+0x1d4/0x430 sound/core/seq/seq_ports.c:576
snd_seq_ioctl_subscribe_port+0x32c/0x6f0 sound/core/seq/seq_clientmgr.c:1490
snd_seq_oss_midi_open+0x4c0/0x7c0 sound/core/seq/oss/seq_oss_midi.c:374
snd_seq_oss_synth_setup_midi+0x129/0x520 sound/core/seq/oss/seq_oss_synth.c:269
snd_seq_oss_open+0x87a/0xe40 sound/core/seq/oss/seq_oss_init.c:261
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1340 [inline]
free_pcp_prepare mm/page_alloc.c:1391 [inline]
free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
free_unref_page+0x94/0x280 mm/page_alloc.c:3396
free_slab mm/slub.c:2015 [inline]
discard_slab mm/slub.c:2021 [inline]
__unfreeze_partials+0x1a5/0x200 mm/slub.c:2507
put_cpu_partial+0x12d/0x190 mm/slub.c:2587
qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176
kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283
__kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444
kasan_slab_alloc include/linux/kasan.h:254 [inline]
slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
slab_alloc_node mm/slub.c:3220 [inline]
slab_alloc mm/slub.c:3228 [inline]
kmem_cache_alloc+0x100/0x290 mm/slub.c:3233
vm_area_dup+0x1e/0xb0 kernel/fork.c:358
__split_vma+0xb1/0x410 mm/mmap.c:2718
mprotect_fixup+0x50c/0x800 mm/mprotect.c:477
do_mprotect_pkey+0x657/0x910 mm/mprotect.c:636
__do_sys_mprotect mm/mprotect.c:662 [inline]
__se_sys_mprotect mm/mprotect.c:659 [inline]
__x64_sys_mprotect+0x7c/0x90 mm/mprotect.c:659
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
Memory state around the buggy address:
ffff88805fdf9f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88805fdf9f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88805fdfa000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88805fdfa080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88805fdfa100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
0: 74 05 je 0x7
2: e8 ee 4f d3 f7 call 0xf7d34ff5
7: 48 c7 44 24 20 00 00 movq $0x0,0x20(%rsp)
e: 00 00
10: 9c pushf
11: 8f 44 24 20 pop 0x20(%rsp)
15: f6 44 24 21 02 testb $0x2,0x21(%rsp)
1a: 75 4b jne 0x67
1c: f7 c3 00 02 00 00 test $0x200,%ebx
22: 74 01 je 0x25
24: fb sti
25: bf 01 00 00 00 mov $0x1,%edi
* 2a: e8 c6 cf a6 f7 call 0xf7a6cff5 <-- trapping instruction
2f: 65 8b 05 67 e3 57 76 mov %gs:0x7657e367(%rip),%eax # 0x7657e39d
36: 85 c0 test %eax,%eax
38: 74 3c je 0x76
3a: 48 rex.W
3b: c7 .byte 0xc7
3c: 04 24 add $0x24,%al
3e: 0e (bad)
3f: 36 ss