INFO: task syz-executor:14761 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:24056 pid:14761 tgid:14761 ppid:1 task_flags:0x400140 flags:0x00080003
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7376
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
rwsem_down_write_slowpath+0x4c2/0x12a0 kernel/locking/rwsem.c:1215
__down_write_common kernel/locking/rwsem.c:1347 [inline]
__down_write kernel/locking/rwsem.c:1356 [inline]
down_write+0x1c0/0x1f0 kernel/locking/rwsem.c:1632
rdma_dev_exit_net+0x174/0x6b0 drivers/infiniband/core/device.c:1156
ops_exit_list net/core/net_namespace.c:200 [inline]
ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:253
setup_net+0x1fa/0x3a0 net/core/net_namespace.c:459
copy_net_ns+0x345/0x7a0 net/core/net_namespace.c:582
create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:132
unshare_nsproxy_namespaces+0xf2/0x220 kernel/nsproxy.c:234
ksys_unshare+0x4a2/0xb30 kernel/fork.c:3297
__do_sys_unshare kernel/fork.c:3365 [inline]
__se_sys_unshare kernel/fork.c:3363 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:3363
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4f6af9f4a7
RSP: 002b:00007ffd2a634668 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f4f6b225f40 RCX: 00007f4f6af9f4a7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f4f6b2267b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffd2a6348a8 R15: 0000000000000000
</TASK>
Showing all locks held in the system:
locks held by kworker/u8:1/13: 4, on CPU#1:
#0: ffff88801e2e0940 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc90000127d08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:677
#3: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_exit_net+0x261/0x6b0 drivers/infiniband/core/device.c:1190
locks held by khungtaskd/32: 1, last CPU#0:
#0: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6871
locks held by kworker/u8:2/43: 2, on CPU#0:
#0: ffff88801d094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc90000b37d08 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
locks held by kworker/u8:3/45: 2, on CPU#0:
#0: ffff
#0: ffff88801d094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc90000b57d08 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
locks held by kworker/u8:4/64: 3, on CPU#0:
#0: ffff88801d7ac940 ((wq_completion)gid-cache-wq){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc9000202fd08 ((work_completion)(&ndev_work->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: ib_enum_all_roce_netdevs+0x89/0x150 drivers/infiniband/core/device.c:2599
locks held by syslogd/4949: 1, last CPU#1:
#0: ffff888025de16f0 (&u->iolock){+.+.}-{4:4}, at: __unix_dgram_recvmsg+0x255/0xc30 net/unix/af_unix.c:2587
locks held by getty/5355: 2, on CPU#1:
#0: ffff8880352ec0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900032432e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
locks held by syz-executor/5594: 2, last CPU#1:
#0: ffff8880257e4080 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
#0: ffff8880257e4080 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x124/0xa00 mm/mmap.c:1299
#1: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x310 mm/pgtable-generic.c:290
locks held by kworker/u8:9/5827: 4, last CPU#1:
#0: ffff88801d094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc90004c0fd08 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffff888062280800 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6905 [inline]
#2: ffff888062280800 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0x92/0x550 net/wireless/core.c:550
#3: ffffffff8fdec5a0 (rcu_read_lock
){....}-{1:3}, at: raw_spin_rq_lock_nested+0x2c/0x140 kernel/sched/core.c:677
locks held by kworker/0:20/13908: 2, last CPU#0:
#0: ffff88801d059d40 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc900043afd08 ((gc_work).work){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
locks held by kworker/u8:11/14602: 3, last CPU#1:
#0: ffff88801d094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc900051cfd08 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffff88803b332258 (&devlink->lock_key#7){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x56/0xd20 drivers/net/netdevsim/dev.c:834
locks held by syz-executor/14761: 2, on CPU#0:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e41c8 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_exit_net+0x174/0x6b0 drivers/infiniband/core/device.c:1156
locks held by kworker/u8:13/14784: 4, last CPU#1:
#0: ffff88803526b140 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc90002e8fd08 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffff88802a75d1c8 (&hard_iface->bat_iv.ogm_buff_mutex){+.+.}-{4:4}, at: batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:1010 [inline]
#2: ffff88802a75d1c8 (&hard_iface->bat_iv.ogm_buff_mutex){+.+.}-{4:4}, at: batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:1005 [inline]
#2: ffff88802a75d1c8 (&hard_iface->bat_iv.ogm_buff_mutex){+.+.}-{4:4}, at: batadv_iv_send_outstanding_bat_ogm_packet+0x50f/0x7d0 net/batman-adv/bat_iv_ogm.c:1924
#3: ffff8880b833bf60 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x140 kernel/sched/core.c:677
locks held by syz.5.3277/14810: 2, on CPU#0:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_exit_net+0x1f2/0x6b0 drivers/infiniband/core/device.c:1164
locks held by syz.3.3281/14829: 1, on CPU#1:
#0: ffffffff8fdf8378 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3904
locks held by syz-executor/14862: 2, on CPU#1:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff8fdf8378 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3904
locks held by syz-executor/14874: 2, on CPU#1:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff8fdf8378 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3904
locks held by syz-executor/14895: 3, on CPU#0:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
#2: ffffffff918e41c8 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x2ff/0x590 drivers/infiniband/core/device.c:1226
locks held by syz-executor/14978: 4, on CPU#0:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
#2: ffffffff918e41c8 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x2ff/0x590 drivers/infiniband/core/device.c:1226
#3: ffff888034395020 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0x112/0x820 drivers/infiniband/core/device.c:976
locks held by syz-executor/14994: 3, on CPU#1:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
#2: ffffffff918e41c8 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x2ff/0x590 drivers/infiniband/core/device.c:1226
locks held by syz-executor/15018: 3, on CPU#1:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
#2: ffffffff918e41c8 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x2ff/0x590 drivers/infiniband/core/device.c:1226
locks held by syz.4.3319/15098: 5, last CPU#1:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
#2: ffffffff918e41c8 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x2ff/0x590 drivers/infiniband/core/device.c:1226
#3: ffff888034395020 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0x112/0x820 drivers/infiniband/core/device.c:976
#4: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#4: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#4: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#4: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495
locks held by syz-executor/15101: 2, on CPU#1:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
locks held by syz-executor/15115: 2, on CPU#1:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
locks held by syz-executor/15135: 2, on CPU#1:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
locks held by syz-executor/15149: 2, on CPU#0:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
locks held by syz.0.3323/15153: 3, on CPU#1:
#0: ffffffff9cce9928 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv_msg+0x168/0x6f0 drivers/infiniband/core/netlink.c:164
#1: ffff888034394730 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x23b/0x480 drivers/infiniband/core/device.c:1567
#2: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: disable_device+0xbf/0x280 drivers/infiniband/core/device.c:1310
locks held by syz-executor/15186: 2, on CPU#0:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
locks held by syz-executor/15196: 2, on CPU#1:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
locks held by syz-executor/15205: 2, on CPU#0:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
locks held by syz-executor/15232: 2, on CPU#1:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
locks held by syz-executor/15241: 2, on CPU#1:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
locks held by syz-executor/15280: 2, on CPU#0:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
locks held by syz-executor/15292: 2, on CPU#0:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
locks held by syz-executor/15305: 2, on CPU#1:
#0: ffffffff91cbd048 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff918e4448 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
locks held by dhcpcd-run-hook/15352: 2, last CPU#1:
#0: ffff88807df36540 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
#0: ffff88807df36540 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x124/0xa00 mm/mmap.c:1299
#1: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x310 mm/pgtable-generic.c:290
locks held by modprobe/15356: 1, last CPU#1:
#0: ffff88802c4ac080 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
#0: ffff88802c4ac080 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1f5/0x470 mm/util.c:579
locks held by modprobe/15357: 1, last CPU#1:
#0: ffff88802c4a8f80 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
#0: ffff88802c4a8f80 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1f5/0x470 mm/util.c:579
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026
RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:410
Code: 84 59 fc 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1a 66 03 5d 40 89 da ec <5b> 0f b6 c0 5d 41 5c c3 cc cc cc cc e8 d8 c5 cd fc eb a2 e8 61 c6
RSP: 0018:ffffc90000157958 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: ffffffff85b2c180 RDI: ffffffff9cc7e660
RBP: ffffffff9cc7e620 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 205d323354202020 R12: 0000000000000000
R13: 0000000000000020 R14: fffffbfff398fd21 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888122946000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3e7ef40fe8 CR3: 00000000b3963000 CR4: 00000000003526f0
Call Trace:
<TASK>
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x13a/0x210 drivers/tty/serial/8250/8250_port.c:2013
serial8250_fifo_wait_for_lsr_thre+0x5f/0xd0 drivers/tty/serial/8250/8250_port.c:3270
__serial8250_console_fifo_write+0xa5/0x290 drivers/tty/serial/8250/8250_port.c:3345
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline]
__serial8250_console_write drivers/tty/serial/8250/8250_port.c:3432 [inline]
serial8250_console_write+0x1108/0x14f0 drivers/tty/serial/8250/8250_port.c:3496
nbcon_emit_next_record+0x8f7/0xa70 kernel/printk/nbcon.c:1070
nbcon_emit_one+0x1a8/0x2b0 kernel/printk/nbcon.c:1157
nbcon_kthread_func+0x613/0x7d0 kernel/printk/nbcon.c:1271
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>