INFO: task syz.0.17:6112 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17 state:D stack:27176 pid:6112 tgid:6112 ppid:6027 task_flags:0x400640 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7046 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7061
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x3d7/0x710 kernel/sched/completion.c:121
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269
coredump_wait fs/coredump.c:534 [inline]
vfs_coredump+0x8cf/0x2a60 fs/coredump.c:1131
get_signal+0x1109/0x1340 kernel/signal.c:3019
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:40 [inline]
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
irqentry_exit_to_user_mode+0x81/0x120 kernel/entry/common.c:73
exc_page_fault+0xab/0x100 arch/x86/mm/fault.c:1535
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f7b2584f927
RSP: 002b:00007ffc34045420 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000000000000b RCX: 00000000000249f0
RDX: 00007ffc34045440 RSI: 00007ffc34045570 RDI: 000000000000000b
RBP: 00007f7b25bc7da0 R08: 0000000037b7e1f0 R09: 7fffffffffffffff
R10: 3fffffffffffffff R11: 0000000000000000 R12: 0000000000025098
R13: 00007f7b25bc6090 R14: ffffffffffffffff R15: 00007ffc341436c0
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e53cf20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e53cf20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e53cf20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5626:
#0: ffff88814daa80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by syz-executor/6377:
#0: ffffffff8f0c1a60 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8f0c1a60 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8f0c1a60 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8f953748 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f953748 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8f953748 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056
#2: ffffffff8e5429b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#2: ffffffff8e5429b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6377 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__uart_port_using_nbcon include/linux/serial_core.h:-1 [inline]
RIP: 0010:__uart_port_nbcon_acquire include/linux/serial_core.h:674 [inline]
RIP: 0010:uart_port_lock_irqsave include/linux/serial_core.h:718 [inline]
RIP: 0010:serial8250_console_write+0x4ac/0x1ba0 drivers/tty/serial/8250/8250_port.c:3301
Code: ff e8 b8 55 67 fc 81 e3 00 01 00 00 0f 85 4c 11 00 00 e8 07 52 67 fc e9 ea fe ff ff e8 fd 51 67 fc 90 0f 0b 90 e9 56 fe ff ff <48> 8b 44 24 18 4c 8d 78 78 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00
RSP: 0018:ffffc900044de500 EFLAGS: 00000046
RAX: ffffffff8559b295 RBX: 1ffffffff344dc54 RCX: 0000000000000000
RDX: ffff888020b03c80 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900044de6b0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200089bc7c R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff9a26e2a0 R15: 0000000000000000
FS: 000055557f9c4500(0000) GS:ffff8881257ba000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffb4f7fff8 CR3: 00000000317c2000 CR4: 00000000003526f0
Call Trace:
console_emit_next_record kernel/printk/printk.c:3111 [inline]
console_flush_all+0x6f0/0xb10 kernel/printk/printk.c:3199
__console_flush_and_unlock kernel/printk/printk.c:3258 [inline]
console_unlock+0xbb/0x190 kernel/printk/printk.c:3298
vprintk_emit+0x4c5/0x590 kernel/printk/printk.c:2423
_printk+0xcf/0x120 kernel/printk/printk.c:2448
netdev_info+0x10a/0x160 net/core/dev.c:12702
__dev_set_promiscuity+0x307/0x740 net/core/dev.c:9410
netif_set_promiscuity+0x50/0xe0 net/core/dev.c:9445
dev_set_promiscuity+0x126/0x260 net/core/dev_api.c:287
br_port_set_promisc net/bridge/br_if.c:108 [inline]
br_manage_promisc+0x180/0x560 net/bridge/br_if.c:157
br_add_if+0x642/0xec0 net/bridge/br_if.c:640
do_set_master+0x530/0x6d0 net/core/rtnetlink.c:2948
do_setlink+0xcf0/0x41c0 net/core/rtnetlink.c:3150
rtnl_changelink net/core/rtnetlink.c:3761 [inline]
__rtnl_newlink net/core/rtnetlink.c:3920 [inline]
rtnl_newlink+0x160b/0x1c70 net/core/rtnetlink.c:4057
rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6946
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg+0x219/0x270 net/socket.c:729
__sys_sendto+0x3bd/0x520 net/socket.c:2228
__do_sys_sendto net/socket.c:2235 [inline]
__se_sys_sendto net/socket.c:2231 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2231
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5a22790a7c
Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b
RSP: 002b:00007fffb4f80640 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f5a234f4620 RCX: 00007f5a22790a7c
RDX: 0000000000000028 RSI: 00007f5a234f4670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007fffb4f80694 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f5a234f4670 R15: 0000000000000000