==================================================================
BUG: KASAN: slab-use-after-free in find_endpoint+0x2a3/0x2c0 drivers/usb/gadget/udc/dummy_hcd.c:1618
Read of size 1 at addr ffff888035746512 by task kworker/1:2/21548
CPU: 1 UID: 0 PID: 21548 Comm: kworker/1:2 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: usb_hub_wq hub_event
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
find_endpoint+0x2a3/0x2c0 drivers/usb/gadget/udc/dummy_hcd.c:1618
dummy_timer+0x500/0x36f0 drivers/usb/gadget/udc/dummy_hcd.c:1890
__run_hrtimer kernel/time/hrtimer.c:2032 [inline]
__hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096
hrtimer_run_softirq+0x17d/0x2c0 kernel/time/hrtimer.c:2113
handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x162/0x210 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+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:console_flush_one_record+0xac3/0xe50 kernel/printk/printk.c:3270
Code: 00 e8 91 24 2a 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 df d0 21 00 48 85 ed 0f 85 d7 01 00 00 e8 31 d6 21 00 fb 4c 89 e8 <48> c1 e8 03 42 80 3c 38 00 0f 85 64 03 00 00 48 8b 0c 24 48 8b 6b
RSP: 0018:ffffc90004a6e780 EFLAGS: 00000287
RAX: ffffffff8f9ac7d8 RBX: ffffffff8f9ac780 RCX: ffffc90014fb7000
RDX: 0000000000100000 RSI: ffffffff81e88a0f RDI: ffff88807ce80000
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000003d25
R13: ffffffff8f9ac7d8 R14: ffffc90004a6e800 R15: dffffc0000000000
console_flush_all kernel/printk/printk.c:3343 [inline]
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0x103/0x260 kernel/printk/printk.c:3413
vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2479
dev_vprintk_emit+0x391/0x3e0 drivers/base/core.c:4996
dev_printk_emit+0xd2/0x10d drivers/base/core.c:5007
__dev_printk+0xcb/0x100 drivers/base/core.c:5019
_dev_err+0xef/0x127 drivers/base/core.c:5062
mce_write.cold+0x4a/0x145 drivers/media/rc/mceusb.c:849
mce_command_out drivers/media/rc/mceusb.c:911 [inline]
mceusb_get_emulator_version drivers/media/rc/mceusb.c:1412 [inline]
mceusb_dev_probe+0x18d2/0x3790 drivers/media/rc/mceusb.c:1790
usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:628 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:706
__driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
__device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
bus_probe_device+0x64/0x160 drivers/base/bus.c:620
device_add+0x121d/0x1970 drivers/base/core.c:3772
usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2268
usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:628 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:706
__driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
__device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
bus_probe_device+0x64/0x160 drivers/base/bus.c:620
device_add+0x121d/0x1970 drivers/base/core.c:3772
usb_new_device.cold+0x685/0x115c drivers/usb/core/hub.c:2695
hub_port_connect drivers/usb/core/hub.c:5567 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x30a3/0x4a60 drivers/usb/core/hub.c:5953
process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
process_scheduled_works kernel/workqueue.c:3405 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Allocated by task 30284:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5334 [inline]
__kmalloc_noprof+0x322/0x820 mm/slub.c:5359
_kmalloc_noprof include/linux/slab.h:992 [inline]
usb_copy_descriptors+0xcd/0x320 drivers/usb/gadget/config.c:82
f_midi2_bind+0x1dad/0x2770 drivers/usb/gadget/function/f_midi2.c:2026
usb_add_function+0x219/0x890 drivers/usb/gadget/composite.c:333
configfs_composite_bind+0xd83/0x1960 drivers/usb/gadget/configfs.c:1802
gadget_bind_driver+0x28c/0xbf0 drivers/usb/gadget/udc/core.c:1662
call_driver_probe drivers/base/dd.c:628 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:706
__driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
__driver_attach+0x21f/0x5b0 drivers/base/dd.c:1292
bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383
bus_add_driver+0x305/0x5b0 drivers/base/bus.c:763
driver_register+0x1e2/0x360 drivers/base/driver.c:174
usb_gadget_register_driver_owner+0x132/0x210 drivers/usb/gadget/udc/core.c:1752
gadget_dev_desc_UDC_store+0x1b0/0x2e0 drivers/usb/gadget/configfs.c:300
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6ac/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 30334:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5f/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+0x22b/0x6c0 mm/slub.c:6692
usb_free_descriptors include/linux/usb/gadget.h:903 [inline]
usb_free_all_descriptors+0x81/0x1a0 drivers/usb/gadget/config.c:151
purge_configs_funcs+0x285/0x510 drivers/usb/gadget/configfs.c:1600
configfs_composite_unbind+0xae/0x210 drivers/usb/gadget/configfs.c:1846
gadget_unbind_driver+0x20c/0x4f0 drivers/usb/gadget/udc/core.c:1724
device_remove+0xcb/0x180 drivers/base/dd.c:616
__device_release_driver drivers/base/dd.c:1349 [inline]
device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1372
driver_detach+0xd8/0x1b0 drivers/base/dd.c:1435
bus_remove_driver+0x13b/0x2e0 drivers/base/bus.c:832
driver_unregister+0x76/0xb0 drivers/base/driver.c:202
usb_gadget_unregister_driver+0x49/0x70 drivers/usb/gadget/udc/core.c:1784
unregister_gadget drivers/usb/gadget/configfs.c:263 [inline]
gadget_dev_desc_UDC_store+0x170/0x2e0 drivers/usb/gadget/configfs.c:290
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6ac/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff888035746400
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 274 bytes inside of
freed 512-byte region [ffff888035746400, ffff888035746600)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x35744
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 ffff88813fe23c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813fe23c80 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 0xd2800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5024, tgid 5024 (v4l_id), ts 31500407628, free_ts 30811462344
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
prep_new_page mm/page_alloc.c:1867 [inline]
get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946
__alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304
alloc_slab_page mm/slub.c:3266 [inline]
allocate_slab mm/slub.c:3380 [inline]
new_slab+0xa2/0x640 mm/slub.c:3426
refill_objects+0xe3/0x410 mm/slub.c:7310
refill_sheaf mm/slub.c:2804 [inline]
__pcs_replace_empty_main+0x376/0x680 mm/slub.c:4675
alloc_from_pcs mm/slub.c:4773 [inline]
slab_alloc_node mm/slub.c:4905 [inline]
__do_kmalloc_node mm/slub.c:5333 [inline]
__kmalloc_flags_noprof+0x695/0x8b0 mm/slub.c:5528
_kmalloc_flags_noprof mm/slab.h:39 [inline]
__alloc_empty_sheaf mm/slub.c:2751 [inline]
alloc_empty_sheaf mm/slub.c:2771 [inline]
__kfree_rcu_sheaf+0x3dc/0x730 mm/slub.c:6074
kfree_rcu_sheaf mm/slab_common.c:1625 [inline]
kvfree_call_rcu+0x1be/0x4f0 mm/slab_common.c:1974
ma_free_rcu lib/maple_tree.c:173 [inline]
ma_free_rcu+0x40/0x60 lib/maple_tree.c:170
mas_free lib/maple_tree.c:1153 [inline]
mas_replace_node lib/maple_tree.c:1595 [inline]
mas_wr_node_store+0xd1f/0x11b0 lib/maple_tree.c:3201
mas_wr_store_entry+0xcf4/0x1e80 lib/maple_tree.c:3531
mas_store_prealloc+0x6df/0x1090 lib/maple_tree.c:4936
vma_iter_store_new mm/vma.h:623 [inline]
vma_complete+0x9f4/0xf70 mm/vma.c:359
__split_vma+0xa59/0xda0 mm/vma.c:569
vms_gather_munmap_vmas+0x3a5/0x1720 mm/vma.c:1448
page last free pid 4983 tgid 4983 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
__free_frozen_pages+0x79f/0x1090 mm/page_alloc.c:2950
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 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+0x26b/0x6a0 mm/slub.c:4931
alloc_filename fs/namei.c:147 [inline]
do_getname+0x35/0x390 fs/namei.c:187
class_filename_flags_constructor include/linux/fs.h:2566 [inline]
do_sys_openat2+0xc7/0x1e0 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+0x12d/0x210 fs/open.c:1385
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff888035746400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888035746480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888035746500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888035746580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888035746600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
0: 00 e8 add %ch,%al
2: 91 xchg %eax,%ecx
3: 24 2a and $0x2a,%al
5: 00 9c 5d 81 e5 00 02 add %bl,0x200e581(%rbp,%rbx,2)
c: 00 00 add %al,(%rax)
e: 31 ff xor %edi,%edi
10: 48 89 ee mov %rbp,%rsi
13: e8 df d0 21 00 call 0x21d0f7
18: 48 85 ed test %rbp,%rbp
1b: 0f 85 d7 01 00 00 jne 0x1f8
21: e8 31 d6 21 00 call 0x21d657
26: fb sti
27: 4c 89 e8 mov %r13,%rax
* 2a: 48 c1 e8 03 shr $0x3,%rax <-- trapping instruction
2e: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1)
33: 0f 85 64 03 00 00 jne 0x39d
39: 48 8b 0c 24 mov (%rsp),%rcx
3d: 48 rex.W
3e: 8b .byte 0x8b
3f: 6b .byte 0x6b