==================================================================
BUG: KASAN: use-after-free in snd_usbmidi_error_timer+0x5fe/0x660 sound/usb/midi.c:352
Read of size 1 at addr ffff8880552ef143 by task syz-executor/4274
CPU: 0 PID: 4274 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
print_address_description mm/kasan/report.c:316 [inline]
print_report+0xa8/0x210 mm/kasan/report.c:420
kasan_report+0x10b/0x140 mm/kasan/report.c:524
snd_usbmidi_error_timer+0x5fe/0x660 sound/usb/midi.c:352
call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x53e/0x800 kernel/time/timer.c:2023
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x2a1/0x930 kernel/softirq.c:596
__do_softirq kernel/softirq.c:630 [inline]
invoke_softirq kernel/softirq.c:470 [inline]
__irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_release+0x5ab/0x920 kernel/locking/lockdep.c:5686
Code: 00 00 00 f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 2f 04 f8 75 70 f7 44 24 50 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 2f 00 00 00 00 43 c7 44 2f 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc90003cc7420 EFLAGS: 00000206
RAX: 0000000000000001 RBX: b6d80f72a6271125 RCX: 4786d7476abc3000
RDX: 0000000000000005 RSI: ffffffff8a8c23a0 RDI: ffffffff8adf0f60
RBP: ffffc90003cc7530 R08: ffffffff8e1fd76f R09: 1ffffffff1c3faed
R10: dffffc0000000000 R11: fffffbfff1c3faee R12: ffff88802f2a8ba8
R13: dffffc0000000000 R14: ffff88802f2a8ad0 R15: 1ffff92000798e90
page_table_check_pte_set include/linux/page_table_check.h:83 [inline]
set_pte_at arch/x86/include/asm/pgtable.h:1009 [inline]
copy_present_pte mm/memory.c:1000 [inline]
copy_pte_range mm/memory.c:1091 [inline]
copy_pmd_range mm/memory.c:1177 [inline]
copy_pud_range mm/memory.c:1214 [inline]
copy_p4d_range mm/memory.c:1238 [inline]
copy_page_range+0x24ea/0x3900 mm/memory.c:1332
dup_mmap kernel/fork.c:702 [inline]
dup_mm kernel/fork.c:1546 [inline]
copy_mm+0xec3/0x1690 kernel/fork.c:1595
copy_process+0x1979/0x4030 kernel/fork.c:2356
kernel_clone+0x24b/0x900 kernel/fork.c:2762
__do_sys_clone kernel/fork.c:2903 [inline]
__se_sys_clone kernel/fork.c:2887 [inline]
__x64_sys_clone+0x1a7/0x220 kernel/fork.c:2887
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f86ecbc5212
Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffeba8cdd80 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffeba8cdd80 RCX: 00007f86ecbc5212
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffeba8cdf0c R08: 0000000000000000 R09: 0000000000000001
R10: 00005555872167d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 00000000000db297 R15: 00007ffeba8cdf60
Allocated by task 4255:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
____kasan_kmalloc mm/kasan/common.c:375 [inline]
__kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384
kmalloc include/linux/slab.h:563 [inline]
kzalloc include/linux/slab.h:699 [inline]
snd_usbmidi_in_endpoint_create+0x7e/0xa20 sound/usb/midi.c:1342
snd_usbmidi_create_endpoints sound/usb/midi.c:1937 [inline]
__snd_usbmidi_create+0x17d8/0x30b0 sound/usb/midi.c:2659
snd_usb_create_quirk sound/usb/quirks.c:539 [inline]
create_composite_quirk+0x1ec/0x4e0 sound/usb/quirks.c:48
usb_audio_probe+0xb97/0x1d90 sound/usb/card.c:885
usb_probe_interface+0x5c5/0xb20 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x2aa/0xc70 drivers/base/dd.c:639
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:785
driver_probe_device+0x4f/0x420 drivers/base/dd.c:815
__device_attach_driver+0x2c6/0x510 drivers/base/dd.c:943
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a8/0x480 drivers/base/dd.c:1015
bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489
device_add+0xa00/0xfb0 drivers/base/core.c:3697
usb_set_configuration+0x1991/0x1fd0 drivers/usb/core/message.c:2165
usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238
usb_probe_device+0x139/0x270 drivers/usb/core/driver.c:293
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x2aa/0xc70 drivers/base/dd.c:639
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:785
driver_probe_device+0x4f/0x420 drivers/base/dd.c:815
__device_attach_driver+0x2c6/0x510 drivers/base/dd.c:943
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a8/0x480 drivers/base/dd.c:1015
bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489
device_add+0xa00/0xfb0 drivers/base/core.c:3697
usb_new_device+0xd66/0x1650 drivers/usb/core/hub.c:2659
hub_port_connect drivers/usb/core/hub.c:5517 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
port_event drivers/usb/core/hub.c:5817 [inline]
hub_event+0x2dcf/0x5560 drivers/usb/core/hub.c:5899
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Freed by task 4255:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1729 [inline]
slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755
slab_free mm/slub.c:3687 [inline]
__kmem_cache_free+0xb6/0x1f0 mm/slub.c:3700
snd_usbmidi_free sound/usb/midi.c:1530 [inline]
snd_usbmidi_rawmidi_free+0xaa/0x150 sound/usb/midi.c:1590
snd_rawmidi_free+0x3b7/0x3e0 sound/core/rawmidi.c:1908
snd_rawmidi_dev_free+0x34/0x40 sound/core/rawmidi.c:1917
__snd_device_free+0x1cd/0x2e0 sound/core/device.c:76
snd_device_free_all+0xcb/0x180 sound/core/device.c:233
snd_card_do_free sound/core/init.c:603 [inline]
release_card_device+0x6b/0x1a0 sound/core/init.c:145
device_release+0x92/0x1c0 drivers/base/core.c:-1
kobject_cleanup lib/kobject.c:681 [inline]
kobject_release lib/kobject.c:712 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x21d/0x460 lib/kobject.c:729
snd_card_free_when_closed sound/core/init.c:633 [inline]
snd_card_free+0x14b/0x1e0 sound/core/init.c:666
usb_audio_probe+0x18bd/0x1d90 sound/usb/card.c:939
usb_probe_interface+0x5c5/0xb20 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x2aa/0xc70 drivers/base/dd.c:639
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:785
driver_probe_device+0x4f/0x420 drivers/base/dd.c:815
__device_attach_driver+0x2c6/0x510 drivers/base/dd.c:943
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a8/0x480 drivers/base/dd.c:1015
bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489
device_add+0xa00/0xfb0 drivers/base/core.c:3697
usb_set_configuration+0x1991/0x1fd0 drivers/usb/core/message.c:2165
usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238
usb_probe_device+0x139/0x270 drivers/usb/core/driver.c:293
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x2aa/0xc70 drivers/base/dd.c:639
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:785
driver_probe_device+0x4f/0x420 drivers/base/dd.c:815
__device_attach_driver+0x2c6/0x510 drivers/base/dd.c:943
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a8/0x480 drivers/base/dd.c:1015
bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489
device_add+0xa00/0xfb0 drivers/base/core.c:3697
usb_new_device+0xd66/0x1650 drivers/usb/core/hub.c:2659
hub_port_connect drivers/usb/core/hub.c:5517 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
port_event drivers/usb/core/hub.c:5817 [inline]
hub_event+0x2dcf/0x5560 drivers/usb/core/hub.c:5899
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
The buggy address belongs to the object at ffff8880552ef000
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 323 bytes inside of
512-byte region [ffff8880552ef000, ffff8880552ef200)
The buggy address belongs to the physical page:
page:ffffea000154bb00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x552ec
head:ffffea000154bb00 order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888017441c80
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4267, tgid 4267 (syz-executor), ts 77683098004, free_ts 17969511535
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2559
prep_new_page mm/page_alloc.c:2566 [inline]
get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4357
__alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5657
alloc_slab_page+0x5d/0x160 mm/slub.c:1799
allocate_slab mm/slub.c:1944 [inline]
new_slab+0x87/0x2c0 mm/slub.c:1997
___slab_alloc+0xbc6/0x1240 mm/slub.c:3154
__slab_alloc mm/slub.c:3240 [inline]
slab_alloc_node mm/slub.c:3325 [inline]
__kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3398
__do_kmalloc_node mm/slab_common.c:935 [inline]
__kmalloc_node_track_caller+0x9e/0x230 mm/slab_common.c:956
kmalloc_reserve net/core/skbuff.c:446 [inline]
__alloc_skb+0x22a/0x7e0 net/core/skbuff.c:515
alloc_skb include/linux/skbuff.h:1303 [inline]
netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline]
netlink_sendmsg+0x654/0xbd0 net/netlink/af_netlink.c:1847
sock_sendmsg_nosec net/socket.c:718 [inline]
__sock_sendmsg net/socket.c:730 [inline]
__sys_sendto+0x497/0x650 net/socket.c:2152
__do_sys_sendto net/socket.c:2164 [inline]
__se_sys_sendto net/socket.c:2160 [inline]
__x64_sys_sendto+0xda/0xf0 net/socket.c:2160
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1486 [inline]
free_pcp_prepare mm/page_alloc.c:1536 [inline]
free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3413
free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3508
free_contig_range+0x9d/0x150 mm/page_alloc.c:9625
destroy_args+0xf0/0xa0a mm/debug_vm_pgtable.c:1031
debug_vm_pgtable+0x33c/0x38e mm/debug_vm_pgtable.c:1359
do_one_initcall+0x26a/0x840 init/main.c:1310
do_initcall_level+0x137/0x1e4 init/main.c:1383
do_initcalls+0x4b/0x8a init/main.c:1399
kernel_init_freeable+0x415/0x5be init/main.c:1638
kernel_init+0x19/0x1b0 init/main.c:1526
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Memory state around the buggy address:
ffff8880552ef000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880552ef080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880552ef100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880552ef180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880552ef200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 f7 add %dh,%bh
4: 84 24 80 test %ah,(%rax,%rax,4)
7: 00 00 add %al,(%rax)
9: 00 00 add %al,(%rax)
b: 02 00 add (%rax),%al
d: 00 43 c6 add %al,-0x3a(%rbx)
10: 44 2f rex.R (bad)
12: 04 f8 add $0xf8,%al
14: 75 70 jne 0x86
16: f7 44 24 50 00 02 00 testl $0x200,0x50(%rsp)
1d: 00
1e: 74 01 je 0x21
20: fb sti
21: 48 c7 44 24 60 0e 36 movq $0x45e0360e,0x60(%rsp)
28: e0 45
* 2a: 4b c7 04 2f 00 00 00 movq $0x0,(%r15,%r13,1) <-- trapping instruction
31: 00
32: 43 c7 44 2f 08 00 00 movl $0x0,0x8(%r15,%r13,1)
39: 00 00
3b: 65 gs
3c: 48 rex.W
3d: 8b .byte 0x8b
3e: 04 25 add $0x25,%al