==================================================================
BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:404 [inline]
BUG: KASAN: slab-use-after-free in driver_deferred_probe_del+0x78/0x240 drivers/base/dd.c:149
Read of size 8 at addr ffff888103b630a8 by task syz.0.28/571
CPU: 0 UID: 0 PID: 571 Comm: syz.0.28 Not tainted syzkaller #0 PREEMPT f05419519fe32d4123e2de2c46f5f78942ab245d
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:94
dump_stack_lvl+0x9c/0xf0 lib/dump_stack.c:120
print_address_description+0x77/0x210 mm/kasan/report.c:378
print_report+0x5b/0x80 mm/kasan/report.c:482
kasan_report+0x165/0x1a0 mm/kasan/report.c:595
__asan_report_load8_noabort+0x18/0x20 mm/kasan/report_generic.c:381
list_empty include/linux/list.h:404 [inline]
driver_deferred_probe_del+0x78/0x240 drivers/base/dd.c:149
device_del+0x589/0xce0 drivers/base/core.c:3963
usb_del_gadget+0x18f/0x250 drivers/usb/gadget/udc/core.c:1591
usb_del_gadget_udc+0x19/0x30 drivers/usb/gadget/udc/core.c:1614
dummy_udc_remove+0x5c/0x70 drivers/usb/gadget/udc/dummy_hcd.c:1142
platform_remove+0x81/0xa0 drivers/base/platform.c:1456
device_remove drivers/base/dd.c:616 [inline]
__device_release_driver drivers/base/dd.c:1349 [inline]
device_release_driver_internal+0x495/0x8c0 drivers/base/dd.c:1372
device_driver_detach+0x3f/0x50 drivers/base/dd.c:1408
unbind_store+0x1a8/0x1f0 drivers/base/bus.c:244
drv_attr_store+0x91/0xb0 drivers/base/bus.c:125
sysfs_kf_write+0x1c0/0x200 fs/sysfs/file.c:145
kernfs_fop_write_iter+0x31a/0x520 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x72c/0xf50 fs/read_write.c:687
ksys_write+0x14d/0x260 fs/read_write.c:739
__do_sys_write fs/read_write.c:750 [inline]
__se_sys_write fs/read_write.c:747 [inline]
__x64_sys_write+0x7f/0x90 fs/read_write.c:747
x64_sys_call+0x2762/0x3040 arch/x86/include/generated/asm/syscalls_64.h:2
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe0/0x300 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fc50499e019
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:00007fc50594c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fc504c25fa0 RCX: 00007fc50499e019
RDX: 000000000000000b RSI: 0000200000000400 RDI: 0000000000000003
RBP: 00007fc504a3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc504c26038 R14: 00007fc504c25fa0 R15: 00007ffc9f60bf18
Allocated by task 569:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_alloc_info+0x3a/0x50 mm/kasan/generic.c:570
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x9a/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x1cd/0x350 mm/slub.c:5489
_kmalloc_noprof include/linux/slab.h:988 [inline]
_kzalloc_noprof include/linux/slab.h:1309 [inline]
device_private_init drivers/base/core.c:3602 [inline]
device_add+0xc4/0xb20 drivers/base/core.c:3653
usb_add_gadget+0x430/0x770 drivers/usb/gadget/udc/core.c:1461
usb_add_gadget_udc_release drivers/usb/gadget/udc/core.c:1517 [inline]
usb_add_gadget_udc+0x159/0x1c0 drivers/usb/gadget/udc/core.c:1564
dummy_udc_probe+0x70b/0x810 drivers/usb/gadget/udc/dummy_hcd.c:1121
platform_probe+0x125/0x1d0 drivers/base/platform.c:1439
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x2d3/0x950 drivers/base/dd.c:706
__driver_probe_device+0x1e1/0x2b0 drivers/base/dd.c:868
device_driver_attach+0xd8/0x1f0 drivers/base/dd.c:1203
bind_store+0x1dc/0x230 drivers/base/bus.c:267
drv_attr_store+0x91/0xb0 drivers/base/bus.c:125
sysfs_kf_write+0x1c0/0x200 fs/sysfs/file.c:145
kernfs_fop_write_iter+0x31a/0x520 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x72c/0xf50 fs/read_write.c:687
ksys_write+0x14d/0x260 fs/read_write.c:739
__do_sys_write fs/read_write.c:750 [inline]
__se_sys_write fs/read_write.c:747 [inline]
__x64_sys_write+0x7f/0x90 fs/read_write.c:747
x64_sys_call+0x2762/0x3040 arch/x86/include/generated/asm/syscalls_64.h:2
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe0/0x300 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Freed by task 571:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x44/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x63/0x90 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+0x16e/0x430 mm/slub.c:6692
device_release+0xde/0x210 drivers/base/core.c:2640
kobject_cleanup lib/kobject.c:689 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x1ab/0x2a0 lib/kobject.c:737
put_device+0x23/0x50 drivers/base/core.c:3880
klist_devices_put+0x3c/0x60 drivers/base/bus.c:905
klist_put lib/klist.c:221 [inline]
klist_del+0xf8/0x120 lib/klist.c:230
bus_remove_device+0x43d/0x490 drivers/base/bus.c:660
device_del+0x579/0xce0 drivers/base/core.c:3961
usb_del_gadget+0x18f/0x250 drivers/usb/gadget/udc/core.c:1591
usb_del_gadget_udc+0x19/0x30 drivers/usb/gadget/udc/core.c:1614
dummy_udc_remove+0x5c/0x70 drivers/usb/gadget/udc/dummy_hcd.c:1142
platform_remove+0x81/0xa0 drivers/base/platform.c:1456
device_remove drivers/base/dd.c:616 [inline]
__device_release_driver drivers/base/dd.c:1349 [inline]
device_release_driver_internal+0x495/0x8c0 drivers/base/dd.c:1372
device_driver_detach+0x3f/0x50 drivers/base/dd.c:1408
unbind_store+0x1a8/0x1f0 drivers/base/bus.c:244
drv_attr_store+0x91/0xb0 drivers/base/bus.c:125
sysfs_kf_write+0x1c0/0x200 fs/sysfs/file.c:145
kernfs_fop_write_iter+0x31a/0x520 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x72c/0xf50 fs/read_write.c:687
ksys_write+0x14d/0x260 fs/read_write.c:739
__do_sys_write fs/read_write.c:750 [inline]
__se_sys_write fs/read_write.c:747 [inline]
__x64_sys_write+0x7f/0x90 fs/read_write.c:747
x64_sys_call+0x2762/0x3040 arch/x86/include/generated/asm/syscalls_64.h:2
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe0/0x300 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The buggy address belongs to the object at ffff888103b63000
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 168 bytes inside of
freed 256-byte region [ffff888103b63000, ffff888103b63100)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888103b62e00 pfn:0x103b62
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4000000000000240(workingset|head|zone=1)
page_type: f5(slab)
raw: 4000000000000240 ffff888100041b40 ffffea000452fa10 ffff888100040490
raw: ffff888103b62e00 0000001000100002 00000000f5000000 0000000000000000
head: 4000000000000240 ffff888100041b40 ffffea000452fa10 ffff888100040490
head: ffff888103b62e00 0000001000100002 00000000f5000000 0000000000000000
head: 4000000000000001 ffffea00040ed881 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 569, tgid 568 (syz.1.27), ts 42250175202, free_ts 40545156732
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x20f/0x240 mm/page_alloc.c:1859
prep_new_page mm/page_alloc.c:1867 [inline]
get_page_from_freelist+0x1f54/0x1fc0 mm/page_alloc.c:3946
__alloc_frozen_pages_noprof+0x2ce/0x540 mm/page_alloc.c:5304
alloc_slab_page+0x2d/0x110 mm/slub.c:-1
allocate_slab+0x72/0x450 mm/slub.c:3380
new_slab mm/slub.c:3426 [inline]
refill_objects+0x590/0x690 mm/slub.c:7310
refill_sheaf mm/slub.c:2804 [inline]
__pcs_replace_empty_main+0x1a1/0x3f0 mm/slub.c:4675
alloc_from_pcs mm/slub.c:4773 [inline]
slab_alloc_node mm/slub.c:4905 [inline]
__kmalloc_cache_noprof+0x25d/0x350 mm/slub.c:5485
_kmalloc_noprof include/linux/slab.h:988 [inline]
_kzalloc_noprof include/linux/slab.h:1309 [inline]
device_private_init drivers/base/core.c:3602 [inline]
device_add+0xc4/0xb20 drivers/base/core.c:3653
usb_add_gadget+0x384/0x770 drivers/usb/gadget/udc/core.c:1448
usb_add_gadget_udc_release drivers/usb/gadget/udc/core.c:1517 [inline]
usb_add_gadget_udc+0x159/0x1c0 drivers/usb/gadget/udc/core.c:1564
dummy_udc_probe+0x70b/0x810 drivers/usb/gadget/udc/dummy_hcd.c:1121
platform_probe+0x125/0x1d0 drivers/base/platform.c:1439
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x2d3/0x950 drivers/base/dd.c:706
__driver_probe_device+0x1e1/0x2b0 drivers/base/dd.c:868
device_driver_attach+0xd8/0x1f0 drivers/base/dd.c:1203
page last free pid 458 tgid 458 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
__free_frozen_pages+0xaa2/0xba0 mm/page_alloc.c:2950
free_frozen_pages+0xf/0x30 mm/page_alloc.c:2988
__free_slab+0x129/0x1d0 mm/slub.c:3441
free_slab+0x1b/0x120 mm/slub.c:3475
discard_slab+0x23/0x40 mm/slub.c:3481
__slab_free+0x22f/0x270 mm/slub.c:5741
___cache_free+0x7d/0xa0 mm/slub.c:6449
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0xbe/0x130 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x14f/0x180 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x28/0x90 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]
__do_kmalloc_node mm/slub.c:5333 [inline]
__kmalloc_node_noprof+0x1d0/0x470 mm/slub.c:5346
_kmalloc_node_noprof include/linux/slab.h:1197 [inline]
qdisc_alloc+0x90/0x860 net/sched/sch_generic.c:998
qdisc_create_dflt+0x94/0x410 net/sched/sch_generic.c:1053
attach_one_default_qdisc net/sched/sch_generic.c:1219 [inline]
netdev_for_each_tx_queue include/linux/netdevice.h:2735 [inline]
attach_default_qdiscs net/sched/sch_generic.c:1237 [inline]
dev_activate+0x309/0x1170 net/sched/sch_generic.c:1296
__dev_open+0x5a3/0x750 net/core/dev.c:1711
__dev_change_flags+0x23c/0x710 net/core/dev.c:9760
Memory state around the buggy address:
ffff888103b62f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888103b63000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888103b63080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888103b63100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888103b63180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: lib/refcount.c:28 at refcount_warn_saturate+0xb6/0x110 lib/refcount.c:28, CPU#0: syz.0.28/571
Modules linked in:
CPU: 0 UID: 0 PID: 571 Comm: syz.0.28 Tainted: G B syzkaller #0 PREEMPT f05419519fe32d4123e2de2c46f5f78942ab245d
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:refcount_warn_saturate+0xb6/0x110 lib/refcount.c:28
Code: 50 da 4f 05 67 48 0f b9 3a eb 4a e8 a4 af c8 fe 48 8d 3d 4d da 4f 05 67 48 0f b9 3a eb 37 e8 91 af c8 fe 48 8d 3d 4a da 4f 05 <67> 48 0f b9 3a eb 24 e8 7e af c8 fe 48 8d 3d 47 da 4f 05 67 48 0f
RSP: 0018:ffffc900012e79f8 EFLAGS: 00010293
RAX: ffffffff82e13cff RBX: 0000000000000003 RCX: ffff888115955a00
RDX: 0000000000000000 RSI: ffffffff87c73e00 RDI: ffffffff88311750
RBP: ffffc900012e7a08 R08: ffff888115955a00 R09: 0000000000000005
R10: 0000000000000004 R11: 0000000000000000 R12: 0000000000000000
R13: ffff888103ab0c74 R14: ffff888103ab0c70 R15: ffff888103ab0c70
FS: 00007fc50594c6c0(0000) GS:ffff88826dc70000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc7f6c7cd4 CR3: 000000010b3f0000 CR4: 00000000003526b0
Call Trace:
__refcount_sub_and_test include/linux/refcount.h:400 [inline]
__refcount_dec_and_test include/linux/refcount.h:432 [inline]
refcount_dec_and_test include/linux/refcount.h:450 [inline]
kref_put include/linux/kref.h:64 [inline]
kobject_put+0x25b/0x2a0 lib/kobject.c:737
put_device+0x23/0x50 drivers/base/core.c:3880
usb_put_gadget include/linux/usb/gadget.h:507 [inline]
usb_del_gadget_udc+0x25/0x30 drivers/usb/gadget/udc/core.c:1615
dummy_udc_remove+0x5c/0x70 drivers/usb/gadget/udc/dummy_hcd.c:1142
platform_remove+0x81/0xa0 drivers/base/platform.c:1456
device_remove drivers/base/dd.c:616 [inline]
__device_release_driver drivers/base/dd.c:1349 [inline]
device_release_driver_internal+0x495/0x8c0 drivers/base/dd.c:1372
device_driver_detach+0x3f/0x50 drivers/base/dd.c:1408
unbind_store+0x1a8/0x1f0 drivers/base/bus.c:244
drv_attr_store+0x91/0xb0 drivers/base/bus.c:125
sysfs_kf_write+0x1c0/0x200 fs/sysfs/file.c:145
kernfs_fop_write_iter+0x31a/0x520 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x72c/0xf50 fs/read_write.c:687
ksys_write+0x14d/0x260 fs/read_write.c:739
__do_sys_write fs/read_write.c:750 [inline]
__se_sys_write fs/read_write.c:747 [inline]
__x64_sys_write+0x7f/0x90 fs/read_write.c:747
x64_sys_call+0x2762/0x3040 arch/x86/include/generated/asm/syscalls_64.h:2
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe0/0x300 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fc50499e019
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:00007fc50594c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fc504c25fa0 RCX: 00007fc50499e019
RDX: 000000000000000b RSI: 0000200000000400 RDI: 0000000000000003
RBP: 00007fc504a3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc504c26038 R14: 00007fc504c25fa0 R15: 00007ffc9f60bf18
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
0: 50 push %rax
1: da 4f 05 fimull 0x5(%rdi)
4: 67 48 0f b9 3a ud1 (%edx),%rdi
9: eb 4a jmp 0x55
b: e8 a4 af c8 fe call 0xfec8afb4
10: 48 8d 3d 4d da 4f 05 lea 0x54fda4d(%rip),%rdi # 0x54fda64
17: 67 48 0f b9 3a ud1 (%edx),%rdi
1c: eb 37 jmp 0x55
1e: e8 91 af c8 fe call 0xfec8afb4
23: 48 8d 3d 4a da 4f 05 lea 0x54fda4a(%rip),%rdi # 0x54fda74
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: eb 24 jmp 0x55
31: e8 7e af c8 fe call 0xfec8afb4
36: 48 8d 3d 47 da 4f 05 lea 0x54fda47(%rip),%rdi # 0x54fda84
3d: 67 addr32
3e: 48 rex.W
3f: 0f .byte 0xf