INFO: task syz.0.2381:14543 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2381 state:D stack:27192 pid:14543 tgid:14542 ppid:5606 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x1709/0x5530 kernel/sched/core.c:7231
__schedule_loop kernel/sched/core.c:7308 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7604
rt_mutex_slowlock_block+0x55c/0x680 kernel/locking/rtmutex.c:1670
__rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1787 [inline]
rt_mutex_slowlock+0x2d4/0x780 kernel/locking/rtmutex.c:1827
__rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline]
mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578
sync_bdevs+0x276/0x470 block/bdev.c:1358
ksys_sync fs/sync.c:105 [inline]
__ia32_sys_sync+0xc5/0x120 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fce4190de59
RSP: 002b:00007fce3fb66028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fce41b95fa0 RCX: 00007fce4190de59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fce41b95fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fce41b96038 R14: 00007fce41b95fa0 R15: 00007ffd98640fc8
Showing all locks held in the system:
2 locks held by ktimers/1/30:
#0: ffff8880b873b920 (&rq->__lock){-...}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:667
#1: ffff8880b8724540 (psi_seq){-...}-{0:0}, at: psi_task_switch+0x57/0x7d0 kernel/sched/psi.c:933
1 lock held by khungtaskd/40:
#0: ffff[ 1026.389703][ T40] #0: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffff[ 1026.389703][ T40] #0: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffff[ 1026.389703][ T40] #0: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6821
2 locks held by getty/5347:
#0: ffff888036cd40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211
5 locks held by kworker/0:6/5731:
#0: ffff88801b313538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffff88801b313538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffff88801b313538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#1: ffffc9000585fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffc9000585fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#1: ffffc9000585fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#2: ffff888029fc6210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff888029fc6210 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4cf0 drivers/usb/core/hub.c:5899
#3: ffff88802aa57658 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
#3: ffff88802aa57658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
#3: ffff88802aa57658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#3: ffff88802aa57658 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#3: ffff88802aa57658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x20ad/0x4cf0 drivers/usb/core/hub.c:5953
#4: ffff8880293aa658 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
#4: ffff8880293aa658 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#4: ffff8880293aa658 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#4: ffff8880293aa658 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x20e1/0x4cf0 drivers/usb/core/hub.c:5953
5 locks held by kworker/u8:21/7744:
#0: ffff88803350f138 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffff88803350f138 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffff88803350f138 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#1: ffffc9001f25fc60 ((work_completion)(&(&bat_priv->tt.work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffc9001f25fc60 ((work_completion)(&(&bat_priv->tt.work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#1: ffffc9001f25fc60 ((work_completion)(&(&bat_priv->tt.work)->work)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#2: ffffffff8e0592e0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#3: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#4: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#4: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#4: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
#4: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57
11 locks held by kworker/0:14/9006:
#0: ffff888060a90138 ((wq_completion)wg-kex-wg2#6){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffff888060a90138 ((wq_completion)wg-kex-wg2#6){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffff888060a90138 ((wq_completion)wg-kex-wg2#6){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#1: ffffc90009477c60 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ((typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))))((unsigned long)((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))) + (((__per_cpu_offset[(cpu)]))))); })->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffc90009477c60 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ((typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))))((unsigned long)((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))) + (((__per_cpu_offset[(cpu)]))))); })->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#1: ffffc90009477c60 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ((typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))))((unsigned long)((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))) + (((__per_cpu_offset[(cpu)]))))); })->work)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#2: ffffffff8e0592e0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#3: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#4: ffff88803997a240 (&peer->endpoint_lock){++..}-{3:3}, at: read_lock_bh include/linux/rwlock_rt.h:45 [inline]
#4: ffff88803997a240 (&peer->endpoint_lock){++..}-{3:3}, at: wg_socket_send_skb_to_peer+0x6e/0x200 drivers/net/wireguard/socket.c:172
#5: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#5: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#5: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rt_read_lock+0x277/0x4b0 kernel/locking/spinlock_rt.c:251
#6: ffffffff8e0592e0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#7: ffffffff8e1c3820 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#7: ffffffff8e1c3820 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:893 [inline]
#7: ffffffff8e1c3820 (rcu_read_lock_bh){....}-{1:3}, at: send6+0x255/0x920 drivers/net/wireguard/socket.c:118
#8: ffffe8ffffc7a570 ((&({ do { const void *__vpp_verify = (typeof((dst_cache->cache) + 0))((void *)0); (void)__vpp_verify; } while (0); ((typeof((__typeof_unqual__(*((dst_cache->cache))) *)(( unsigned long)((dst_cache->cache)))))((unsigned long)((__typeof_unqual__(*((dst_cache->cache))) *)(( unsigned long)((dst_cache->cache)))) + (((__per_cpu_offset[(i)]))))); })->bh_lock)){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#8: ffffe8ffffc7a570 ((&({ do { const void *__vpp_verify = (typeof((dst_cache->cache) + 0))((void *)0); (void)__vpp_verify; } while (0); ((typeof((__typeof_unqual__(*((dst_cache->cache))) *)(( unsigned long)((dst_cache->cache)))))((unsigned long)((__typeof_unqual__(*((dst_cache->cache))) *)(( unsigned long)((dst_cache->cache)))) + (((__per_cpu_offset[(i)]))))); })->bh_lock)){+...}-{3:3}, at: dst_cache_set_ip6+0xb9/0x580 net/core/dst_cache.c:128
#9: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#9: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#9: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
#9: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57
#10: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#10: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#10: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
#10: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
1 lock held by udevd/12195:
#0: ffff888027c0f4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd00 block/bdev.c:991
1 lock held by syz.0.2381/14543:
#0: ffff888027c0f4c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x276/0x470 block/bdev.c:1358
8 locks held by syz-executor/15785:
#0: ffff8880363cc510 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2731 [inline]
#0: ffff8880363cc510 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#1: ffff88803b1cec78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336
#2: ffff888029accc38 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff888029accc38 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337
#3: ffffffff8ee20a38 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234
#4: ffff8880618ff160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#4: ffff8880618ff160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline]
#4: ffff8880618ff160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369
#5: ffff88803b332310 (&devlink->lock_key#4){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1799
#6: ffffffff8f5ac2f8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x173/0x800 drivers/net/netdevsim/netdev.c:1191
#7: ffff8880618c5070 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2852 [inline]
#7: ffff8880618c5070 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x5bb/0x2120 net/core/dev.c:12425
2 locks held by syz.1.2773/15896:
#0: ffff88803b61acb0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline]
#0: ffff88803b61acb0 (&mm->mmap_lock){++++}-{4:4}, at: do_pages_stat_array mm/migrate.c:2451 [inline]
#0: ffff88803b61acb0 (&mm->mmap_lock){++++}-{4:4}, at: do_pages_stat mm/migrate.c:2530 [inline]
#0: ffff88803b61acb0 (&mm->mmap_lock){++++}-{4:4}, at: kernel_move_pages mm/migrate.c:2616 [inline]
#0: ffff88803b61acb0 (&mm->mmap_lock){++++}-{4:4}, at: __do_sys_move_pages mm/migrate.c:2627 [inline]
#0: ffff88803b61acb0 (&mm->mmap_lock){++++}-{4:4}, at: __se_sys_move_pages+0x15eb/0x1d90 mm/migrate.c:2622
#1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: mtree_load+0x12a/0x780 lib/maple_tree.c:5783
3 locks held by syz.4.2795/15987:
#0: ffff888034bf0510 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x210 fs/namespace.c:538
#1: ffffffff8e2eecc0 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:317 [inline]
#1: ffffffff8e2eecc0 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4559 [inline]
#1: ffffffff8e2eecc0 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:4897 [inline]
#1: ffffffff8e2eecc0 (fs_reclaim){+.+.}-{0:0}, at: kmem_cache_alloc_noprof+0x5c/0x680 mm/slub.c:4933
#2: ffffffff8e3042e0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: fs_reclaim_acquire+0x7c/0x100 mm/page_alloc.c:4346
2 locks held by syz.6.2800/16006:
#0: ffff88801beaa510 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2731 [inline]
#0: ffff88801beaa510 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#1: ffff88803a2c3810 (&sb->s_type->i_mutex_key#14){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#1: ffff88803a2c3810 (&sb->s_type->i_mutex_key#14){++++}-{4:4}, at: shmem_file_write_iter+0x82/0x120 mm/shmem.c:3404
6 locks held by syz-executor/16007:
#0: ffff888025ed8948 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310
#1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: do_fault_around mm/memory.c:5810 [inline]
#1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: do_read_fault mm/memory.c:5844 [inline]
#1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: do_fault mm/memory.c:5987 [inline]
#1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: do_pte_missing+0x12cd/0x28f0 mm/memory.c:4559
#2: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#2: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#2: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: filemap_map_pages+0x1db/0x1d10 mm/filemap.c:3910
#3: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#3: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290
#4: ffff888062c8d1d8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#4: ffff888062c8d1d8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404
#5: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#5: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#5: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
#5: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 40 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
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: 17 Comm: pr/legacy Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401
Code: e8 1e 88 6f fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 2f 6c db fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0000:ffffc90000167a28 EFLAGS: 00000202
RAX: 1ffffffff33c8200 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff85559460 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff99e41480 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125c49000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f92a0adeac0 CR3: 000000002c598000 CR4: 00000000003526f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x190/0x300 drivers/tty/serial/8250/8250_port.c:1982
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3229 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3294 [inline]
serial8250_console_write+0x113a/0x1b40 drivers/tty/serial/8250/8250_port.c:3379
console_emit_next_record kernel/printk/printk.c:3163 [inline]
console_flush_one_record+0x642/0xb50 kernel/printk/printk.c:3269
legacy_kthread_func+0x1b6/0x250 kernel/printk/printk.c:3712
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245