==================================================================
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+0xcf6/0x4cf0 drivers/usb/gadget/udc/dummy_hcd.c:1890
Read of size 1 at addr ffff88807ea9d4da by task pvrusb2-context/2352
CPU: 0 UID: 0 PID: 2352 Comm: pvrusb2-context Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
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+0xcf6/0x4cf0 drivers/usb/gadget/udc/dummy_hcd.c:1890
__run_hrtimer kernel/time/hrtimer.c:2032 [inline]
__hrtimer_run_queues+0x3bc/0xa10 kernel/time/hrtimer.c:2096
hrtimer_run_softirq+0x17a/0x240 kernel/time/hrtimer.c:2113
handle_softirqs+0x225/0x840 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
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:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198
Code: f7 e8 5d 3d ce f5 f7 c3 00 02 00 00 74 05 e8 c0 1d fa f5 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 f4 50 bf f5 65 8b 05 bd 50 98 07 85 c0 74 18 5b 41 5e e9 8c 21
RSP: 0018:ffffc9000756f5f0 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000246 RCX: 0000000080000001
RDX: 0000000000000006 RSI: ffffffff8e22cadd RDI: 0000000000000001
RBP: 0000000000000007 R08: ffffffff90578f37 R09: 1ffffffff20af1e6
R10: dffffc0000000000 R11: fffffbfff20af1e7 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88801b118000 R15: 1ffff110055fee94
spin_unlock_irqrestore include/linux/spinlock.h:408 [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:1542
pvr2_send_request_ex+0xc8e/0x2240 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:3674
pvr2_send_request drivers/media/usb/pvrusb2/pvrusb2-hdw.c:3822 [inline]
pvr2_issue_simple_cmd+0x7bd/0xa10 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:3882
pvr2_hdw_cmd_powerup drivers/media/usb/pvrusb2/pvrusb2-hdw.c:4011 [inline]
pvr2_hdw_setup_low drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2121 [inline]
pvr2_hdw_setup drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2261 [inline]
pvr2_hdw_initialize+0x580/0x3c60 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2338
pvr2_context_check drivers/media/usb/pvrusb2/pvrusb2-context.c:111 [inline]
pvr2_context_thread_func+0x504/0xc10 drivers/media/usb/pvrusb2/pvrusb2-context.c:158
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Allocated by task 5874:
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:5334 [inline]
__kmalloc_noprof+0x375/0x720 mm/slub.c:5359
_kmalloc_noprof include/linux/slab.h:992 [inline]
usb_copy_descriptors+0xf7/0x320 drivers/usb/gadget/config.c:82
f_midi2_bind+0x2736/0x2c40 drivers/usb/gadget/function/f_midi2.c:2026
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:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 6609:
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:2677 [inline]
slab_free mm/slub.c:6377 [inline]
kfree+0x1c5/0x640 mm/slub.c:6692
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:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88807ea9d400
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 218 bytes inside of
freed 512-byte region [ffff88807ea9d400, ffff88807ea9d600)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7ea9c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b001c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b001c80 dead000000000100 dead000000000122
head: 0000000000000000 0000000800100010 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 5874, tgid 5871 (syz.3.9), ts 95201853665, free_ts 94625793354
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859
prep_new_page mm/page_alloc.c:1867 [inline]
get_page_from_freelist+0x21fa/0x2270 mm/page_alloc.c:3946
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304
alloc_slab_page mm/slub.c:3266 [inline]
allocate_slab+0x79/0x5e0 mm/slub.c:3380
new_slab mm/slub.c:3426 [inline]
refill_objects+0x2d5/0x350 mm/slub.c:7310
refill_sheaf mm/slub.c:2804 [inline]
__pcs_replace_empty_main+0x2bf/0x6b0 mm/slub.c:4675
alloc_from_pcs mm/slub.c:4773 [inline]
slab_alloc_node mm/slub.c:4905 [inline]
__kmalloc_cache_noprof+0x3a7/0x660 mm/slub.c:5485
_kmalloc_noprof include/linux/slab.h:988 [inline]
snd_mixer_oss_build_test+0x7a/0x380 sound/core/oss/mixer_oss.c:896
snd_mixer_oss_build_test_all sound/core/oss/mixer_oss.c:981 [inline]
snd_mixer_oss_build_input+0x5a8/0x1370 sound/core/oss/mixer_oss.c:1020
snd_mixer_oss_build sound/core/oss/mixer_oss.c:1279 [inline]
snd_mixer_oss_notify_handler+0x93f/0x1050 sound/core/oss/mixer_oss.c:1347
snd_card_register+0x589/0x720 sound/core/init.c:931
f_midi2_create_card drivers/usb/gadget/function/f_midi2.c:1616 [inline]
f_midi2_bind+0x1562/0x2c40 drivers/usb/gadget/function/f_midi2.c:1948
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 5730 tgid 5730 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
__free_frozen_pages+0xc1e/0xd10 mm/page_alloc.c:2950
__slab_free+0x274/0x2c0 mm/slub.c:5741
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4584 [inline]
slab_alloc_node mm/slub.c:4917 [inline]
kmem_cache_alloc_noprof+0x2a0/0x5f0 mm/slub.c:4931
alloc_filename fs/namei.c:147 [inline]
do_getname+0x2e/0x250 fs/namei.c:187
class_filename_flags_constructor include/linux/fs.h:2566 [inline]
do_sys_openat2+0xcc/0x200 fs/open.c:1367
do_sys_open fs/open.c:1374 [inline]
__do_sys_openat fs/open.c:1390 [inline]
__se_sys_openat fs/open.c:1385 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1385
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff88807ea9d380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88807ea9d400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807ea9d480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88807ea9d500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88807ea9d580: 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: 5d pop %rbp
3: 3d ce f5 f7 c3 cmp $0xc3f7f5ce,%eax
8: 00 02 add %al,(%rdx)
a: 00 00 add %al,(%rax)
c: 74 05 je 0x13
e: e8 c0 1d fa f5 call 0xf5fa1dd3
13: 9c pushf
14: 58 pop %rax
15: a9 00 02 00 00 test $0x200,%eax
1a: 75 27 jne 0x43
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 f4 50 bf f5 call 0xf5bf5123 <-- trapping instruction
2f: 65 8b 05 bd 50 98 07 mov %gs:0x79850bd(%rip),%eax # 0x79850f3
36: 85 c0 test %eax,%eax
38: 74 18 je 0x52
3a: 5b pop %rbx
3b: 41 5e pop %r14
3d: e9 .byte 0xe9
3e: 8c 21 mov %fs,(%rcx)