==================================================================
BUG: KASAN: slab-use-after-free in find_endpoint drivers/usb/gadget/udc/dummy_hcd.c:1618 [inline]
BUG: KASAN: slab-use-after-free in dummy_timer+0xcdb/0x4cf0 drivers/usb/gadget/udc/dummy_hcd.c:1890
Read of size 1 at addr ffff888050e8a8e8 by task syz.0.554/8173
CPU: 0 UID: 0 PID: 8173 Comm: syz.0.554 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description+0x55/0x1e0 mm/kasan/report.c:378
print_report+0x58/0x70 mm/kasan/report.c:482
kasan_report+0x117/0x150 mm/kasan/report.c:595
find_endpoint drivers/usb/gadget/udc/dummy_hcd.c:1618 [inline]
dummy_timer+0xcdb/0x4cf0 drivers/usb/gadget/udc/dummy_hcd.c:1890
__run_hrtimer kernel/time/hrtimer.c:2067 [inline]
__hrtimer_run_queues+0x3bc/0xa10 kernel/time/hrtimer.c:2124
hrtimer_run_softirq+0x1e3/0x2e0 kernel/time/hrtimer.c:2141
handle_softirqs+0x226/0x860 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758
irq_exit_rcu+0x9/0x30 kernel/softirq.c:775
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:211 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:221
Code: f7 e8 bd eb aa f5 f7 c3 00 02 00 00 74 05 e8 10 35 d7 f5 9c 58 a9 00 02 00 00 75 29 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 54 00 9c f5 65 48 8b 05 dc 38 c3 07 48 85 c0 74 18 5b 41 5e c3
RSP: 0018:ffffc90003a5f620 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000246 RCX: 8000000000000001
RDX: 0000000000000006 RSI: ffffffff8e59e74c RDI: 0000000000000001
RBP: 0000000000000007 R08: ffffffff909bb37f R09: 1ffffffff213766f
R10: dffffc0000000000 R11: fffffbfff2137670 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88801b728000 R15: 1ffff1100533b694
spin_unlock_irqrestore include/linux/spinlock.h:425 [inline]
dummy_urb_enqueue+0x587/0x780 drivers/usb/gadget/udc/dummy_hcd.c:1337
usb_hcd_submit_urb+0x328/0x1b60 drivers/usb/core/hcd.c:1543
ti_open+0x59c/0xd20 drivers/usb/serial/ti_usb_3410_5052.c:669
serial_port_activate+0x151/0x250 drivers/usb/serial/usb-serial.c:268
tty_port_open+0x1d7/0x2b0 drivers/tty/tty_port.c:769
tty_open+0x48a/0xd80 drivers/tty/tty_io.c:2110
chrdev_open+0x4d9/0x600 fs/char_dev.c:411
do_dentry_open+0x80e/0x1360 fs/open.c:1000
vfs_open_consume+0x4a/0x350 fs/open.c:1131
do_open fs/namei.c:4913 [inline]
path_openat+0x14d7/0x1e40 fs/namei.c:5078
do_file_open+0x23e/0x4a0 fs/namei.c:5107
do_sys_openat2+0x115/0x200 fs/open.c:1452
do_sys_open fs/open.c:1458 [inline]
__do_sys_openat fs/open.c:1474 [inline]
__se_sys_openat fs/open.c:1469 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1469
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc81919e159
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:00007fc819fee028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fc819425fa0 RCX: 00007fc81919e159
RDX: 0000000000000002 RSI: 0000200000000200 RDI: ffffffffffffff9c
RBP: 00007fc81923503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc819426038 R14: 00007fc819425fa0 R15: 00007fff29167b68
Allocated by task 7157:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5419 [inline]
__kmalloc_noprof+0x366/0x710 mm/slub.c:5444
_kmalloc_noprof include/linux/slab.h:995 [inline]
usb_copy_descriptors+0xf7/0x320 drivers/usb/gadget/config.c:82
f_midi2_bind+0x2736/0x2c40 drivers/usb/gadget/function/f_midi2.c:2025
usb_add_function+0x2e1/0x9f0 drivers/usb/gadget/composite.c:333
configfs_composite_bind+0xde0/0x1410 drivers/usb/gadget/configfs.c:1802
gadget_bind_driver+0x2ca/0x9e0 drivers/usb/gadget/udc/core.c:1662
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x254/0xae0 drivers/base/dd.c:706
__driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
__driver_attach+0x339/0x600 drivers/base/dd.c:1292
bus_for_each_dev+0x23b/0x2c0 drivers/base/bus.c:383
bus_add_driver+0x345/0x670 drivers/base/bus.c:763
driver_register+0x23a/0x320 drivers/base/driver.c:174
usb_gadget_register_driver_owner+0xf9/0x270 drivers/usb/gadget/udc/core.c:1752
gadget_dev_desc_UDC_store+0x1c9/0x2f0 drivers/usb/gadget/configfs.c:300
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x337/0x430 fs/configfs/file.c:229
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x612/0xba0 fs/read_write.c:687
ksys_write+0x150/0x270 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 8032:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2748 [inline]
slab_free mm/slub.c:6505 [inline]
kfree+0x1c5/0x650 mm/slub.c:6798
usb_free_descriptors include/linux/usb/gadget.h:903 [inline]
usb_free_all_descriptors+0x78/0x110 drivers/usb/gadget/config.c:151
purge_configs_funcs+0x248/0x3d0 drivers/usb/gadget/configfs.c:1600
configfs_composite_unbind+0xa4/0x1c0 drivers/usb/gadget/configfs.c:1846
gadget_unbind_driver+0x1cb/0x410 drivers/usb/gadget/udc/core.c:1724
device_remove drivers/base/dd.c:616 [inline]
__device_release_driver drivers/base/dd.c:1349 [inline]
device_release_driver_internal+0x48b/0x880 drivers/base/dd.c:1372
driver_detach+0x1f3/0x2d0 drivers/base/dd.c:1435
bus_remove_driver+0x226/0x320 drivers/base/bus.c:832
usb_gadget_unregister_driver+0x4e/0x70 drivers/usb/gadget/udc/core.c:1784
unregister_gadget drivers/usb/gadget/configfs.c:263 [inline]
gadget_dev_desc_UDC_store+0x17a/0x2f0 drivers/usb/gadget/configfs.c:290
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x337/0x430 fs/configfs/file.c:229
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x612/0xba0 fs/read_write.c:687
ksys_write+0x150/0x270 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff888050e8a800
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 232 bytes inside of
freed 512-byte region [ffff888050e8a800, ffff888050e8aa00)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888050e89400 pfn:0x50e88
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88813ff1ac80 ffffea0001eb0610 ffffea0001a06a10
raw: ffff888050e89400 000000000010000b 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88813ff1ac80 ffffea0001eb0610 ffffea0001a06a10
head: ffff888050e89400 000000000010000b 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffffffffffff01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
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 7157, tgid 7150 (syz.1.336), ts 146757414719
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1853
prep_new_page mm/page_alloc.c:1861 [inline]
get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3925
__alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5418
alloc_slab_page mm/slub.c:3347 [inline]
allocate_slab+0x7d/0x620 mm/slub.c:3462
new_slab mm/slub.c:3513 [inline]
refill_objects+0x2d5/0x350 mm/slub.c:7416
refill_sheaf mm/slub.c:2885 [inline]
__pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4774
alloc_from_pcs mm/slub.c:4850 [inline]
slab_alloc_node mm/slub.c:4984 [inline]
__kmalloc_cache_noprof+0x396/0x600 mm/slub.c:5564
_kmalloc_noprof include/linux/slab.h:991 [inline]
snd_mixer_oss_build_test+0x7a/0x380 sound/core/oss/mixer_oss.c:893
snd_mixer_oss_build_test_all sound/core/oss/mixer_oss.c:963 [inline]
snd_mixer_oss_build_input+0x425/0x1370 sound/core/oss/mixer_oss.c:1017
snd_mixer_oss_build sound/core/oss/mixer_oss.c:1276 [inline]
snd_mixer_oss_notify_handler+0x93f/0x1050 sound/core/oss/mixer_oss.c:1344
snd_card_register+0x589/0x720 sound/core/init.c:935
f_midi2_create_card drivers/usb/gadget/function/f_midi2.c:1615 [inline]
f_midi2_bind+0x1562/0x2c40 drivers/usb/gadget/function/f_midi2.c:1947
usb_add_function+0x2e1/0x9f0 drivers/usb/gadget/composite.c:333
configfs_composite_bind+0xde0/0x1410 drivers/usb/gadget/configfs.c:1802
gadget_bind_driver+0x2ca/0x9e0 drivers/usb/gadget/udc/core.c:1662
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x254/0xae0 drivers/base/dd.c:706
page last free pid 6895 tgid 6891 ts 136452567621 stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1400 [inline]
free_unref_folios+0xdc2/0x14e0 mm/page_alloc.c:3004
folios_put_refs+0x9e9/0xb30 mm/folio.c:1036
folio_batch_release include/linux/folio_batch.h:101 [inline]
truncate_inode_pages_range+0x3ca/0xd70 mm/truncate.c:408
kill_bdev block/bdev.c:90 [inline]
blkdev_flush_mapping+0x109/0x2f0 block/bdev.c:757
blkdev_put_whole block/bdev.c:764 [inline]
bdev_release+0x443/0x690 block/bdev.c:1189
blkdev_release+0x15/0x20 block/fops.c:683
__fput+0x413/0xa50 fs/file_table.c:513
task_work_run+0x1d9/0x260 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x73a/0x2360 kernel/exit.c:1008
do_group_exit+0x22d/0x2f0 kernel/exit.c:1151
get_signal+0x1216/0x12c0 kernel/signal.c:3051
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff888050e8a780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888050e8a800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888050e8a880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888050e8a900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888050e8a980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
0: f7 e8 imul %eax
2: bd eb aa f5 f7 mov $0xf7f5aaeb,%ebp
7: c3 ret
8: 00 02 add %al,(%rdx)
a: 00 00 add %al,(%rax)
c: 74 05 je 0x13
e: e8 10 35 d7 f5 call 0xf5d73523
13: 9c pushf
14: 58 pop %rax
15: a9 00 02 00 00 test $0x200,%eax
1a: 75 29 jne 0x45
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 54 00 9c f5 call 0xf59c0083 <-- trapping instruction
2f: 65 48 8b 05 dc 38 c3 mov %gs:0x7c338dc(%rip),%rax # 0x7c33913
36: 07
37: 48 85 c0 test %rax,%rax
3a: 74 18 je 0x54
3c: 5b pop %rbx
3d: 41 5e pop %r14
3f: c3 ret