Hello,
syzbot found the following issue on:
HEAD commit: 3f5b4c104b7d Linux 6.6.95
git tree: linux-6.6.y
console output:
https://syzkaller.appspot.com/x/log.txt?x=17af93d4580000
kernel config:
https://syzkaller.appspot.com/x/.config?x=b80883c3ded77c16
dashboard link:
https://syzkaller.appspot.com/bug?extid=8c9af143864c35b66658
compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image:
https://storage.googleapis.com/syzbot-assets/0efd4e01816e/disk-3f5b4c10.raw.xz
vmlinux:
https://storage.googleapis.com/syzbot-assets/f7c9d20858cc/vmlinux-3f5b4c10.xz
kernel image:
https://storage.googleapis.com/syzbot-assets/18f8dc74ef68/bzImage-3f5b4c10.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by:
syzbot+8c9af1...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: slab-use-after-free in __lock_acquire+0xff/0x7c80 kernel/locking/lockdep.c:5005
Read of size 8 at addr ffff888058b16098 by task kworker/1:4/5820
CPU: 1 PID: 5820 Comm: kworker/1:4 Not tainted 6.6.95-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events do_submit_urb
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xac/0x230 mm/kasan/report.c:475
kasan_report+0x117/0x150 mm/kasan/report.c:588
__lock_acquire+0xff/0x7c80 kernel/locking/lockdep.c:5005
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
get_entry drivers/media/common/siano/smscoreapi.c:1633 [inline]
smscore_getbuffer+0xa9/0x440 drivers/media/common/siano/smscoreapi.c:1646
smsusb_submit_urb drivers/media/usb/siano/smsusb.c:155 [inline]
do_submit_urb+0x98/0x360 drivers/media/usb/siano/smsusb.c:75
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Allocated by task 2128:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
____kasan_kmalloc mm/kasan/common.c:374 [inline]
__kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383
kmalloc include/linux/slab.h:600 [inline]
kzalloc include/linux/slab.h:721 [inline]
smscore_register_device+0x63/0x10f0 drivers/media/common/siano/smscoreapi.c:650
smsusb_init_device drivers/media/usb/siano/smsusb.c:455 [inline]
smsusb_probe+0x1362/0x1da0 drivers/media/usb/siano/smsusb.c:569
usb_probe_interface+0x5a4/0xb00 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x25b/0xb40 drivers/base/dd.c:658
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:800
driver_probe_device+0x4f/0x420 drivers/base/dd.c:830
__device_attach_driver+0x2ca/0x520 drivers/base/dd.c:958
bus_for_each_drv+0x24b/0x2d0 drivers/base/bus.c:459
__device_attach+0x2b5/0x400 drivers/base/dd.c:1030
bus_probe_device+0x180/0x260 drivers/base/bus.c:534
device_add+0x85b/0xc20 drivers/base/core.c:3683
usb_set_configuration+0x1a79/0x20c0 drivers/usb/core/message.c:2207
usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:238
usb_probe_device+0x13d/0x280 drivers/usb/core/driver.c:293
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x25b/0xb40 drivers/base/dd.c:658
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:800
driver_probe_device+0x4f/0x420 drivers/base/dd.c:830
__device_attach_driver+0x2ca/0x520 drivers/base/dd.c:958
bus_for_each_drv+0x24b/0x2d0 drivers/base/bus.c:459
__device_attach+0x2b5/0x400 drivers/base/dd.c:1030
bus_probe_device+0x180/0x260 drivers/base/bus.c:534
device_add+0x85b/0xc20 drivers/base/core.c:3683
usb_new_device+0xa31/0x1630 drivers/usb/core/hub.c:2632
hub_port_connect drivers/usb/core/hub.c:5501 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5641 [inline]
port_event drivers/usb/core/hub.c:5801 [inline]
hub_event+0x2957/0x49c0 drivers/usb/core/hub.c:5883
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Freed by task 2128:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1806 [inline]
slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1832
slab_free mm/slub.c:3816 [inline]
__kmem_cache_free+0xba/0x1f0 mm/slub.c:3829
smscore_unregister_device+0x603/0x6e0 drivers/media/common/siano/smscoreapi.c:1242
smsusb_term_device+0x18f/0x220 drivers/media/usb/siano/smsusb.c:349
smsusb_init_device drivers/media/usb/siano/smsusb.c:491 [inline]
smsusb_probe+0x1708/0x1da0 drivers/media/usb/siano/smsusb.c:569
usb_probe_interface+0x5a4/0xb00 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x25b/0xb40 drivers/base/dd.c:658
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:800
driver_probe_device+0x4f/0x420 drivers/base/dd.c:830
__device_attach_driver+0x2ca/0x520 drivers/base/dd.c:958
bus_for_each_drv+0x24b/0x2d0 drivers/base/bus.c:459
__device_attach+0x2b5/0x400 drivers/base/dd.c:1030
bus_probe_device+0x180/0x260 drivers/base/bus.c:534
device_add+0x85b/0xc20 drivers/base/core.c:3683
usb_set_configuration+0x1a79/0x20c0 drivers/usb/core/message.c:2207
usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:238
usb_probe_device+0x13d/0x280 drivers/usb/core/driver.c:293
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x25b/0xb40 drivers/base/dd.c:658
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:800
driver_probe_device+0x4f/0x420 drivers/base/dd.c:830
__device_attach_driver+0x2ca/0x520 drivers/base/dd.c:958
bus_for_each_drv+0x24b/0x2d0 drivers/base/bus.c:459
__device_attach+0x2b5/0x400 drivers/base/dd.c:1030
bus_probe_device+0x180/0x260 drivers/base/bus.c:534
device_add+0x85b/0xc20 drivers/base/core.c:3683
usb_new_device+0xa31/0x1630 drivers/usb/core/hub.c:2632
hub_port_connect drivers/usb/core/hub.c:5501 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5641 [inline]
port_event drivers/usb/core/hub.c:5801 [inline]
hub_event+0x2957/0x49c0 drivers/usb/core/hub.c:5883
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
__call_rcu_common kernel/rcu/tree.c:2717 [inline]
call_rcu+0x14f/0x920 kernel/rcu/tree.c:2833
netdev_for_each_tx_queue include/linux/netdevice.h:2520 [inline]
dev_shutdown+0x96/0x440 net/sched/sch_generic.c:1489
unregister_netdevice_many_notify+0x8d2/0x1810 net/core/dev.c:11064
unregister_netdevice_many net/core/dev.c:11130 [inline]
unregister_netdevice_queue+0x324/0x360 net/core/dev.c:11010
unregister_netdevice include/linux/netdevice.h:3137 [inline]
__tun_detach+0xd45/0x1500 drivers/net/tun.c:685
tun_detach drivers/net/tun.c:701 [inline]
tun_chr_close+0x10d/0x1c0 drivers/net/tun.c:3511
__fput+0x234/0x970 fs/file_table.c:384
task_work_run+0x1ce/0x250 kernel/task_work.c:239
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
The buggy address belongs to the object at ffff888058b16000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 152 bytes inside of
freed 2048-byte region [ffff888058b16000, ffff888058b16800)
The buggy address belongs to the physical page:
page:ffffea000162c400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x58b10
head:ffffea000162c400 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017842000 ffffea0001785a00 0000000000000002
raw: 0000000000000000 0000000080080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 11195, tgid 11194 (syz.0.2142), ts 259793481441, free_ts 258078355735
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
prep_new_page mm/page_alloc.c:1561 [inline]
get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
__alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
alloc_slab_page+0x5d/0x170 mm/slub.c:1876
allocate_slab mm/slub.c:2023 [inline]
new_slab+0x87/0x2e0 mm/slub.c:2076
___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
__slab_alloc mm/slub.c:3329 [inline]
__slab_alloc_node mm/slub.c:3382 [inline]
slab_alloc_node mm/slub.c:3475 [inline]
__kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524
__do_kmalloc_node mm/slab_common.c:1006 [inline]
__kmalloc_node+0xa4/0x230 mm/slab_common.c:1014
kmalloc_node include/linux/slab.h:620 [inline]
kzalloc_node include/linux/slab.h:732 [inline]
qdisc_alloc+0x94/0xa50 net/sched/sch_generic.c:948
qdisc_create_dflt+0x63/0x430 net/sched/sch_generic.c:1009
mq_init+0x2e3/0x660 net/sched/sch_mq.c:90
qdisc_create_dflt+0x11e/0x430 net/sched/sch_generic.c:1016
attach_default_qdiscs net/sched/sch_generic.c:1196 [inline]
dev_activate+0x1d0/0x11a0 net/sched/sch_generic.c:1250
__dev_open+0x338/0x430 net/core/dev.c:1515
__dev_change_flags+0x20e/0x6a0 net/core/dev.c:8673
dev_change_flags+0x88/0x1a0 net/core/dev.c:8745
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1154 [inline]
free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
discard_slab mm/slub.c:2122 [inline]
__unfreeze_partials+0x1cf/0x210 mm/slub.c:2662
put_cpu_partial+0x17c/0x250 mm/slub.c:2738
__slab_free+0x31d/0x410 mm/slub.c:3686
qlink_free mm/kasan/quarantine.c:166 [inline]
qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
slab_alloc_node mm/slub.c:3485 [inline]
slab_alloc mm/slub.c:3493 [inline]
__kmem_cache_alloc_lru mm/slub.c:3500 [inline]
kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509
getname_flags+0xbb/0x500 fs/namei.c:140
do_sys_openat2+0xcb/0x1c0 fs/open.c:1413
do_sys_open fs/open.c:1434 [inline]
__do_sys_openat fs/open.c:1450 [inline]
__se_sys_openat fs/open.c:1445 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1445
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Memory state around the buggy address:
ffff888058b15f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888058b16000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888058b16080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888058b16100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888058b16180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
---
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