==================================================================
BUG: KASAN: slab-use-after-free in lock_timer_base+0x234/0x270 kernel/time/timer.c:1000
Read of size 4 at addr ffff888028097cb0 by task syz.3.2340/13349
CPU: 1 PID: 13349 Comm: syz.3.2340 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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
lock_timer_base+0x234/0x270 kernel/time/timer.c:1000
__mod_timer+0xf9/0xdb0 kernel/time/timer.c:1080
call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x542/0x800 kernel/time/timer.c:2023
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x280/0x820 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:deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline]
RIP: 0010:unwind_next_frame+0x1606/0x2970 arch/x86/kernel/unwind_orc.c:585
Code: 0f 84 7f 08 00 00 e8 59 d4 4b 00 48 8b 6c 24 10 4c 8b 7c 24 38 4c 89 f7 e8 57 20 00 00 49 89 c6 48 8b 44 24 40 42 80 3c 28 00 <48> 8b 5c 24 20 74 08 48 89 df e8 5b 0c a4 00 4c 89 33 48 8b 44 24
RSP: 0018:ffffc900195af478 EFLAGS: 00000246
RAX: 1ffff920032b5eb2 RBX: ffffc900195a8000 RCX: 0000000000080000
RDX: ffffc9000d68b000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc900195af598 R08: ffff88801d2e5a00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000002 R12: ffffc900195af548
R13: dffffc0000000000 R14: ffffffff81f363cd R15: ffffffff8f89eef0
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
ref_tracker_alloc+0x1b7/0x4c0 lib/ref_tracker.c:209
__netdev_tracker_alloc include/linux/netdevice.h:4110 [inline]
netdev_hold include/linux/netdevice.h:4139 [inline]
qdisc_alloc+0x75f/0xa50 net/sched/sch_generic.c:989
qdisc_create_dflt+0x63/0x430 net/sched/sch_generic.c:1012
mq_init+0x2e2/0x680 net/sched/sch_mq.c:90
qdisc_create_dflt+0x11e/0x430 net/sched/sch_generic.c:1019
attach_default_qdiscs net/sched/sch_generic.c:1199 [inline]
dev_activate+0x1d0/0x11a0 net/sched/sch_generic.c:1253
__dev_open+0x347/0x430 net/core/dev.c:1528
__dev_change_flags+0x211/0x6a0 net/core/dev.c:8723
dev_change_flags+0x88/0x1a0 net/core/dev.c:8795
dev_ioctl+0x7b4/0x1140 net/core/dev_ioctl.c:770
sock_do_ioctl+0x239/0x310 net/socket.c:1233
sock_ioctl+0x5ba/0x7e0 net/socket.c:1340
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+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd9a359cdd9
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:00007fd9a4390028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd9a3815fa0 RCX: 00007fd9a359cdd9
RDX: 0000200000002280 RSI: 0000000000008914 RDI: 0000000000000006
RBP: 00007fd9a3632d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd9a3816038 R14: 00007fd9a3815fa0 R15: 00007ffc6e3bd1d8
Allocated by task 9913:
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]
rose_add_node+0x23c/0xf00 net/rose/rose_route.c:85
rose_rt_ioctl+0xd2c/0x1290 net/rose/rose_route.c:748
rose_ioctl+0x3fc/0x8f0 net/rose/af_rose.c:1386
sock_do_ioctl+0xfc/0x310 net/socket.c:1219
sock_ioctl+0x5ba/0x7e0 net/socket.c:1340
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+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Freed by task 13352:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1811 [inline]
slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
__kmem_cache_free+0xba/0x1e0 mm/slub.c:3843
rose_neigh_put include/net/rose.h:166 [inline]
rose_timer_expiry+0x4c6/0x5f0 net/rose/rose_timer.c:183
call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x542/0x800 kernel/time/timer.c:2023
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x280/0x820 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
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/0x790 kernel/rcu/tree.c:3452
__ipv6_dev_mc_dec+0x2cc/0x330 net/ipv6/mcast.c:981
ipv6_mc_destroy_dev+0x338/0x590 net/ipv6/mcast.c:2804
addrconf_ifdown+0x13cf/0x18c0 net/ipv6/addrconf.c:3986
addrconf_notify+0x6c6/0x1010 net/ipv6/addrconf.c:-1
notifier_call_chain+0x197/0x380 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+0x100d/0x1900 net/core/dev.c:11124
unregister_netdevice_many net/core/dev.c:11180 [inline]
unregister_netdevice_queue+0x32c/0x370 net/core/dev.c:11060
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
__do_sys_close fs/open.c:1573 [inline]
__se_sys_close+0x15f/0x220 fs/open.c:1558
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
The buggy address belongs to the object at ffff888028097c00
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 176 bytes inside of
freed 512-byte region [ffff888028097c00, ffff888028097e00)
The buggy address belongs to the physical page:
page:ffffea0000a02500 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28094
head:ffffea0000a02500 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017c41c80 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000100010 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 1, tgid 1 (swapper/0), ts 20751295872, free_ts 0
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1581
prep_new_page mm/page_alloc.c:1588 [inline]
get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3220
__alloc_pages+0x1f0/0x460 mm/page_alloc.c:4500
alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2118
alloc_slab_page+0x5d/0x160 mm/slub.c:1881
allocate_slab mm/slub.c:2028 [inline]
new_slab+0x87/0x2d0 mm/slub.c:2081
___slab_alloc+0xc5d/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+0x19e/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]
device_private_init drivers/base/core.c:3528 [inline]
device_add+0xbe/0xc20 drivers/base/core.c:3579
__video_register_device+0x3987/0x4890 drivers/media/v4l2-core/v4l2-dev.c:1043
video_register_device include/media/v4l2-dev.h:383 [inline]
vivid_create_devnodes+0x1453/0x2cd0 drivers/media/test-drivers/vivid/vivid-core.c:1546
vivid_create_instance drivers/media/test-drivers/vivid/vivid-core.c:1951 [inline]
vivid_probe+0x47e8/0x5c80 drivers/media/test-drivers/vivid/vivid-core.c:2004
platform_probe+0x13b/0x1c0 drivers/base/platform.c:1404
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x25b/0xb20 drivers/base/dd.c:658
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:800
page_owner free stack trace missing
Memory state around the buggy address:
ffff888028097b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888028097c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888028097c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888028097d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888028097d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
0: 0f 84 7f 08 00 00 je 0x885
6: e8 59 d4 4b 00 call 0x4bd464
b: 48 8b 6c 24 10 mov 0x10(%rsp),%rbp
10: 4c 8b 7c 24 38 mov 0x38(%rsp),%r15
15: 4c 89 f7 mov %r14,%rdi
18: e8 57 20 00 00 call 0x2074
1d: 49 89 c6 mov %rax,%r14
20: 48 8b 44 24 40 mov 0x40(%rsp),%rax
25: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
* 2a: 48 8b 5c 24 20 mov 0x20(%rsp),%rbx <-- trapping instruction
2f: 74 08 je 0x39
31: 48 89 df mov %rbx,%rdi
34: e8 5b 0c a4 00 call 0xa40c94
39: 4c 89 33 mov %r14,(%rbx)
3c: 48 rex.W
3d: 8b .byte 0x8b
3e: 44 rex.R
3f: 24 .byte 0x24