INFO: task syz.4.1153:4038 blocked for more than 125 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1153 state:D stack:0 pid:4038 tgid:4010 ppid:1625 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:10868
rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
unregister_netdev+0x156/0x1c0 net/core/dev.c:11570
unregister_candev+0x19/0x30 drivers/net/can/dev/dev.c:576
slcan_close+0x82/0x150 drivers/net/can/slcan/slcan-core.c:880
tty_ldisc_close drivers/tty/tty_ldisc.c:455 [inline]
tty_ldisc_kill drivers/tty/tty_ldisc.c:613 [inline]
tty_ldisc_release+0x2aa/0x600 drivers/tty/tty_ldisc.c:781
tty_release_struct+0x2d/0xe0 drivers/tty/tty_io.c:1690
tty_release+0xc0a/0x1230 drivers/tty/tty_io.c:1861
__fput+0x1fe/0xa00 fs/file_table.c:429
____fput+0x20/0x30 fs/file_table.c:457
task_work_run+0x1e3/0x250 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: 0033:0x7f4d99b8eba9
RSP: 002b:00007f4d9aa2c038 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f4d99dd6090 RCX: 00007f4d99b8eba9
RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000003
RBP: 00007f4d99c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4d99dd6128 R14: 00007f4d99dd6090 R15: 00007ffd392c9808
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 064bd8e71db8281f775729d9237f740d6717dea5
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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+0x2c7/0x370 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: 329 Comm: kworker/u8:3 Not tainted syzkaller #0 064bd8e71db8281f775729d9237f740d6717dea5
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: netns cleanup_net
RIP: 0010:io_serial_in+0x7b/0xc0 drivers/tty/serial/8250/8250_port.c:406
Code: e8 5a 63 6d fe 44 89 f9 d3 e3 49 83 c6 08 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 3b 97 c3 fe 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f 5d c3 cc cc cc cc cc 44 89 f9 80 e1
RSP: 0018:ffffc9000b8ef230 EFLAGS: 00000002
RAX: 1ffffffff113e500 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffffc9000b8ef250 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: ffffffff83188970 R12: dffffc0000000000
R13: 00000000000026cb R14: ffffffff889f2e28 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005568dd78bb90 CR3: 000000010a7b0000 CR4: 00000000003526b0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:137 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline]
wait_for_lsr drivers/tty/serial/8250/8250_port.c:2069 [inline]
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3315 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3337 [inline]
serial8250_console_write+0x147d/0x2130 drivers/tty/serial/8250/8250_port.c:3422
univ8250_console_write+0x6f/0xb0 drivers/tty/serial/8250/8250_core.c:396
console_emit_next_record kernel/printk/printk.c:3152 [inline]
console_flush_all+0x5e3/0xaa0 kernel/printk/printk.c:3240
__console_flush_and_unlock kernel/printk/printk.c:3299 [inline]
console_unlock+0xe9/0x270 kernel/printk/printk.c:3339
vprintk_emit+0x27c/0x640 kernel/printk/printk.c:2463
vprintk_default+0x2a/0x40 kernel/printk/printk.c:2478
vprintk+0x93/0xa0 kernel/printk/printk_safe.c:73
_printk+0xd0/0x120 kernel/printk/printk.c:2488
__netdev_printk+0x3b6/0x4e0 net/core/dev.c:11907
netdev_info+0x10b/0x160 net/core/dev.c:11954
__dev_set_promiscuity+0x1ba/0x570 net/core/dev.c:8712
dev_set_promiscuity+0x54/0x100 net/core/dev.c:8750
nbp_delete_promisc net/bridge/br_if.c:254 [inline]
del_nbp+0x143/0xd20 net/bridge/br_if.c:340
br_dev_delete+0x76/0x130 net/bridge/br_if.c:386
br_net_exit_batch_rtnl+0xff/0x1a0 net/bridge/br.c:369
cleanup_net+0x5f1/0xc70 net/core/net_namespace.c:635
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0x7d5/0x1020 kernel/workqueue.c:3319
worker_thread+0xc58/0x1250 kernel/workqueue.c:3400
kthread+0x2c7/0x370 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
net_ratelimit: 88893 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:3e:9f:e7:33:75:bb, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:3e:9f:e7:33:75:bb, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:3e:9f:e7:33:75:bb, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:3e:9f:e7:33:75:bb, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:3e:9f:e7:33:75:bb, vlan:0)
net_ratelimit: 124354 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:3e:9f:e7:33:75:bb, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:3e:9f:e7:33:75:bb, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:3e:9f:e7:33:75:bb, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:3e:9f:e7:33:75:bb, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:3e:9f:e7:33:75:bb, vlan:0)