==================================================================
BUG: KASAN: slab-use-after-free in find_endpoint drivers/usb/gadget/udc/dummy_hcd.c:1601 [inline]
BUG: KASAN: slab-use-after-free in dummy_timer+0xc59/0x3420 drivers/usb/gadget/udc/dummy_hcd.c:1872
Read of size 1 at addr ffff88801e7760e8 by task syz.0.2619/16920
CPU: 0 PID: 16920 Comm: syz.0.2619 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xa8/0x210 mm/kasan/report.c:468
kasan_report+0x117/0x150 mm/kasan/report.c:581
find_endpoint drivers/usb/gadget/udc/dummy_hcd.c:1601 [inline]
dummy_timer+0xc59/0x3420 drivers/usb/gadget/udc/dummy_hcd.c:1872
__run_hrtimer kernel/time/hrtimer.c:1754 [inline]
__hrtimer_run_queues+0x525/0xc10 kernel/time/hrtimer.c:1818
hrtimer_run_softirq+0x177/0x290 kernel/time/hrtimer.c:1835
handle_softirqs+0x27d/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xc0/0x120 kernel/locking/spinlock.c:194
Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 2b 5f c6 f6 65 8b 05 9c 2d 6d 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90003ea75c0 EFLAGS: 00000206
RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: 460a24dc80ea3f00
RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: 0000000000000001
RBP: ffffc90003ea7658 R08: ffffffff911eb60f R09: 1ffffffff223d6c1
R10: dffffc0000000000 R11: fffffbfff223d6c2 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff8880229fc000 R15: 1ffff920007d4eb8
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
dummy_urb_enqueue+0x587/0x780 drivers/usb/gadget/udc/dummy_hcd.c:1318
usb_hcd_submit_urb+0x318/0x1aa0 drivers/usb/core/hcd.c:1533
usblp_submit_read+0x26c/0x4a0 drivers/usb/class/usblp.c:1034
handle_bidir drivers/usb/class/usblp.c:397 [inline]
usblp_open+0x287/0x430 drivers/usb/class/usblp.c:447
usb_open+0x205/0x300 drivers/usb/core/file.c:47
chrdev_open+0x58c/0x600 fs/char_dev.c:414
do_dentry_open+0x880/0x14b0 fs/open.c:929
do_open fs/namei.c:3640 [inline]
path_openat+0x284f/0x3270 fs/namei.c:3801
do_filp_open+0x1f2/0x430 fs/namei.c:3828
do_sys_openat2+0x134/0x1d0 fs/open.c:1422
do_sys_open fs/open.c:1437 [inline]
__do_sys_openat fs/open.c:1453 [inline]
__se_sys_openat fs/open.c:1448 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1448
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9c7cd5e6ce
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007f9c7dd0fb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f9c7dd106c0 RCX: 00007f9c7cd5e6ce
RDX: 0000000000000002 RSI: 00007f9c7dd0fc00 RDI: ffffffffffffff9c
RBP: 00007f9c7ce33eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9c7d026038 R14: 00007f9c7d025fa0 R15: 00007fff6df2a748
Allocated by task 16738:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
____kasan_kmalloc mm/kasan/common.c:375 [inline]
__kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
kmalloc include/linux/slab.h:600 [inline]
kzalloc include/linux/slab.h:721 [inline]
device_private_init drivers/base/core.c:3530 [inline]
device_add+0xb6/0xc40 drivers/base/core.c:3581
netdev_register_kobject+0x188/0x320 net/core/net-sysfs.c:2042
register_netdevice+0x12aa/0x1ba0 net/core/dev.c:10318
tun_set_iff+0x82b/0xea0 drivers/net/tun.c:2865
__tun_chr_ioctl+0x7e0/0x2070 drivers/net/tun.c:3134
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
kvfree_call_rcu+0xee/0x780 kernel/rcu/tree.c:3452
mld_clear_delrec+0x1ee/0x650 net/ipv6/mcast.c:830
ipv6_mc_destroy_dev+0x45/0x590 net/ipv6/mcast.c:2827
addrconf_ifdown+0x13b8/0x18a0 net/ipv6/addrconf.c:3998
addrconf_notify+0x6c6/0x1010 net/ipv6/addrconf.c:-1
notifier_call_chain+0x18f/0x380 kernel/notifier.c:93
call_netdevice_notifiers_extack net/core/dev.c:2077 [inline]
call_netdevice_notifiers net/core/dev.c:2091 [inline]
unregister_netdevice_many_notify+0x1037/0x1910 net/core/dev.c:11124
unregister_netdevice_many net/core/dev.c:11180 [inline]
default_device_exit_batch+0x962/0xa00 net/core/dev.c:11746
ops_exit_list net/core/net_namespace.c:178 [inline]
cleanup_net+0x792/0xbb0 net/core/net_namespace.c:652
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
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
Second to last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
insert_work+0x3d/0x310 kernel/workqueue.c:1670
__queue_work+0xcf4/0xfd0 kernel/workqueue.c:1823
call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1747 [inline]
__run_timers+0x59c/0x810 kernel/time/timer.c:2023
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x27d/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
The buggy address belongs to the object at ffff88801e776000
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 232 bytes inside of
freed 512-byte region [ffff88801e776000, ffff88801e776200)
The buggy address belongs to the physical page:
page:ffffea000079dd00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88801e776000 pfn:0x1e774
head:ffffea000079dd00 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017c41c80 ffffea0000b00d10 ffffea0000b38d10
raw: ffff88801e776000 000000000010000a 00000001ffffffff 0000000000000000
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 529, tgid 529 (kworker/u4:4), ts 11478484771, free_ts 0
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1582
prep_new_page mm/page_alloc.c:1589 [inline]
get_page_from_freelist+0x2181/0x22a0 mm/page_alloc.c:3221
__alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501
alloc_slab_page+0x5d/0x180 mm/slub.c:1881
allocate_slab mm/slub.c:2028 [inline]
new_slab+0x87/0x2d0 mm/slub.c:2081
___slab_alloc+0xc5c/0x12f0 mm/slub.c:3253
__slab_alloc mm/slub.c:3339 [inline]
__slab_alloc_node mm/slub.c:3392 [inline]
slab_alloc_node mm/slub.c:3485 [inline]
__kmem_cache_alloc_node+0x11f/0x250 mm/slub.c:3534
kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098
kmalloc include/linux/slab.h:600 [inline]
kzalloc include/linux/slab.h:721 [inline]
alloc_bprm+0x56/0x9a0 fs/exec.c:1538
kernel_execve+0x98/0x980 fs/exec.c:2023
call_usermodehelper_exec_async+0x20b/0x350 kernel/umh.c:110
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
page_owner free stack trace missing
Memory state around the buggy address:
ffff88801e775f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88801e776000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88801e776080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88801e776100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88801e776180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
0: c7 44 24 20 00 00 00 movl $0x0,0x20(%rsp)
7: 00
8: 9c pushf
9: 8f 44 24 20 pop 0x20(%rsp)
d: f7 44 24 20 00 02 00 testl $0x200,0x20(%rsp)
14: 00
15: 41 c6 04 07 f8 movb $0xf8,(%r15,%rax,1)
1a: 75 4b jne 0x67
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 2b 5f c6 f6 call 0xf6c65f5a <-- trapping instruction
2f: 65 8b 05 9c 2d 6d 75 mov %gs:0x756d2d9c(%rip),%eax # 0x756d2dd2
36: 85 c0 test %eax,%eax
38: 74 3c je 0x76
3a: 48 rex.W
3b: c7 .byte 0xc7
3c: 04 24 add $0x24,%al
3e: 0e (bad)
3f: 36 ss