INFO: task syz.3.1622:5251 blocked for more than 124 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1622 state:D stack:0 pid:5251 tgid:5249 ppid:291 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5945 [inline]
__schedule+0x1322/0x1df0 kernel/sched/core.c:7791
__schedule_loop kernel/sched/core.c:7872 [inline]
schedule+0xc6/0x240 kernel/sched/core.c:7887
schedule_timeout+0xb2/0x3a0 kernel/time/timer.c:2595
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common+0x359/0x630 kernel/sched/completion.c:127
wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
rcu_barrier+0x415/0x530 kernel/rcu/tree.c:4657
netdev_run_todo+0x10e/0xcb0 net/core/dev.c:10880
rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
tun_detach drivers/net/tun.c:704 [inline]
tun_chr_close+0xc5/0x150 drivers/net/tun.c:3517
__fput+0x1fb/0xa00 fs/file_table.c:429
____fput+0x20/0x30 fs/file_table.c:457
task_work_run+0x1e0/0x250 kernel/task_work.c:240
resume_user_mode_work+0x36/0x50 include/linux/resume_user_mode.h:50
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x64/0xb0 kernel/entry/common.c:218
do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f9003d8efc9
RSP: 002b:00007f9004bf1038 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f9003fe6090 RCX: 00007f9003d8efc9
RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000003
RBP: 00007f9003e11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9003fe6128 R14: 00007f9003fe6090 R15: 00007ffccd866e38
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 0b5ffdee5fcd2f7749818d1ff954e9c21353764e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:94
dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120
dump_stack+0x19/0x20 lib/dump_stack.c:129
nmi_cpu_backtrace+0x2bf/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
watchdog+0xd8f/0xed0 kernel/hung_task.c:423
kthread+0x2ca/0x370 kernel/kthread.c:389
ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5280 Comm: syz-executor Not tainted syzkaller #0 0b5ffdee5fcd2f7749818d1ff954e9c21353764e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__kernel_text_address+0x13/0x40 kernel/extable.c:79
Code: c3 2a 85 00 eb b2 90 b8 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 55 48 89 e5 53 48 89 fb e8 3f 00 00 00 85 c0 <0f> 95 c0 48 81 fb 00 90 d4 87 0f 93 c1 48 81 fb c5 ba e6 87 0f 92
RSP: 0018:ffffc90000230008 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff81dc350e RCX: 0000000000230001
RDX: ffffc90000230170 RSI: 1ffff9200004600a RDI: ffffffff81dc350e
RBP: ffffc90000230010 R08: ffffc90000230110 R09: ffffc90000230108
R10: 0000000000000000 R11: ffffffff817457d0 R12: ffff888118503900
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000046012
FS: 0000555569a72500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa218ff84c0 CR3: 0000000178416000 CR4: 00000000003526b0
Call Trace:
unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_frame.c:19
arch_stack_walk+0x10b/0x170 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0x9d/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:48 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:69
kasan_save_free_info+0x4a/0x60 mm/kasan/generic.c:579
poison_slab_object mm/kasan/common.c:248 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:265
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2421 [inline]
slab_free mm/slub.c:4690 [inline]
kmem_cache_free+0x1c1/0x510 mm/slub.c:4797
kfree_skbmem net/core/skbuff.c:-1 [inline]
__kfree_skb+0x18f/0x210 net/core/skbuff.c:1203
consume_skb+0x65/0x1a0 net/core/skbuff.c:1434
netlink_broadcast_filtered+0x10e1/0x11f0 net/netlink/af_netlink.c:1530
nlmsg_multicast_filtered include/net/netlink.h:1125 [inline]
nlmsg_multicast include/net/netlink.h:1144 [inline]
nlmsg_notify+0xf1/0x1b0 net/netlink/af_netlink.c:2588
rtnl_notify+0x9e/0xd0 net/core/rtnetlink.c:786
fdb_notify+0xce/0x150 net/bridge/br_fdb.c:206
br_fdb_update+0x4b7/0x680 net/bridge/br_fdb.c:941
br_handle_frame_finish+0x39c/0x1720 net/bridge/br_input.c:141
nf_hook_bridge_pre net/bridge/br_input.c:301 [inline]
br_handle_frame+0x5a6/0xba0 net/bridge/br_input.c:424
__netif_receive_skb_core+0xf4b/0x3940 net/core/dev.c:5663
__netif_receive_skb_one_core net/core/dev.c:5767 [inline]
__netif_receive_skb net/core/dev.c:5882 [inline]
process_backlog+0x3e5/0xae0 net/core/dev.c:6218
__napi_poll+0xd3/0x610 net/core/dev.c:6869
napi_poll net/core/dev.c:6938 [inline]
net_rx_action+0x584/0xce0 net/core/dev.c:7060
handle_softirqs+0x1ab/0x630 kernel/softirq.c:621
__do_softirq kernel/softirq.c:659 [inline]
invoke_softirq kernel/softirq.c:476 [inline]
__irq_exit_rcu+0x48/0xc0 kernel/softirq.c:708
irq_exit_rcu+0xd/0x30 kernel/softirq.c:720
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0x82/0x90 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1f/0x30 arch/x86/include/asm/idtentry.h:702
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2076 [inline]
RIP: 0010:vprintk_emit+0x530/0x640 kernel/printk/printk.c:2461
Code: 81 e6 00 02 00 00 31 ff e8 cd 2e 1e 00 48 81 e3 00 02 00 00 75 07 e8 df 29 1e 00 eb 06 e8 d8 29 1e 00 fb c6 05 20 b6 31 07 00 42 fd ff ff e8 c6 29 1e 00 e9 a5 fe ff ff 41 ff ce bf 58 89 41
RSP: 0018:ffffc9000ee0f8c0 EFLAGS: 00000293
RAX: ffffffff8167d4d8 RBX: 0000000000000200 RCX: ffff888118503900
RDX: 0000000000000000 RSI: 0000000000000200 RDI: 0000000000000000
RBP: ffffc9000ee0f988 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52001dc1f08 R12: 1ffff92001dc1f1c
R13: 0000000000000095 R14: 0000000000000000 R15: dffffc0000000000
vprintk_default+0x2a/0x40 kernel/printk/printk.c:2477
vprintk+0x93/0xa0 kernel/printk/printk_safe.c:73
_printk+0xd0/0x120 kernel/printk/printk.c:2487
warn_alloc+0x1a2/0x2a0 mm/page_alloc.c:3986
__vmalloc_area_node mm/vmalloc.c:3664 [inline]
__vmalloc_node_range_noprof+0x68e/0x1420 mm/vmalloc.c:3864
vmalloc_user_noprof+0x77/0x90 mm/vmalloc.c:4024
kcov_ioctl+0x5d/0x5c0 kernel/kcov.c:716
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0x135/0x1b0 fs/ioctl.c:893
__x64_sys_ioctl+0x7f/0xa0 fs/ioctl.c:893
x64_sys_call+0x1878/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f583bb8ebcb
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007fff6b96c400 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000080000 RCX: 00007f583bb8ebcb
RDX: 0000000000080000 RSI: ffffffff80086301 RDI: 00000000000000dc
RBP: 00007f583bde63f8 R08: 00000000000000da R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000