INFO: task udevd:4473 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:23920 pid: 4473 ppid:  3558 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503
 wait_on_page_bit_common+0x8bf/0xeb0 mm/filemap.c:1356
 wait_on_page_bit mm/filemap.c:1417 [inline]
 wait_on_page_locked include/linux/pagemap.h:688 [inline]
 wait_on_page_read mm/filemap.c:3437 [inline]
 do_read_cache_page+0xae6/0x1010 mm/filemap.c:3480
 read_mapping_page include/linux/pagemap.h:515 [inline]
 read_part_sector+0xd7/0x4c0 block/partitions/core.c:726
 adfspart_check_ICS+0xc3/0xe90 block/partitions/acorn.c:360
 check_partition block/partitions/core.c:148 [inline]
 blk_add_partitions block/partitions/core.c:611 [inline]
 bdev_disk_changed+0x936/0x1690 block/partitions/core.c:697
 blkdev_get_whole+0x2f9/0x390 block/bdev.c:678
 blkdev_get_by_dev+0x2da/0xa50 block/bdev.c:823
 blkdev_open+0x128/0x2c0 block/fops.c:466
 do_dentry_open+0x7f7/0xf90 fs/open.c:826
 do_open fs/namei.c:3659 [inline]
 path_openat+0x2718/0x2fb0 fs/namei.c:3793
 do_filp_open+0x1df/0x400 fs/namei.c:3820
 do_sys_openat2+0x14b/0x500 fs/open.c:1255
 do_sys_open fs/open.c:1271 [inline]
 __do_sys_openat fs/open.c:1287 [inline]
 __se_sys_openat fs/open.c:1282 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1282
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f1574d69407
RSP: 002b:00007ffc941b16c0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f1574c7b880 RCX: 00007f1574d69407
RDX: 00000000000a0800 RSI: 0000562965683480 RDI: ffffffffffffff9c
RBP: 0000562965682910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000056296569ff10
R13: 000056296569a410 R14: 0000000000000000 R15: 000056296569ff10
 </TASK>

Showing all locks held in the system:
7 locks held by kworker/u4:0/9:
 #0: ffff888016dcd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc90000ce7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffffffff8d440dd0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:589
 #3: ffffffff8d44cd08 (rtnl_mutex){+.+.}-{3:3}, at: ieee80211_unregister_hw+0x4d/0x220 net/mac80211/main.c:1393
 #4: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #4: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
 #5: ffff8880b913a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x130 kernel/sched/core.c:475
 #6: ffff8880b9127888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x517/0x810 kernel/sched/psi.c:891
1 lock held by khungtaskd/27:
 #0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
3 locks held by kworker/u4:1/144:
 #0: ffff8881465ea938 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc9000169fd00 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffffffff8d44cd08 (rtnl_mutex){+.+.}-{3:3}, at: cfg80211_dfs_channels_update_work+0xc8/0x610 net/wireless/mlme.c:845
1 lock held by dhcpcd/3851:
 #0: ffffffff8d44cd08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d44cd08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x79f/0xf10 net/core/rtnetlink.c:5695
2 locks held by getty/3942:
 #0: ffff88802c5da098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
3 locks held by syz-executor/4186:
2 locks held by kworker/1:7/4231:
 #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc9000457fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
3 locks held by kworker/u4:7/4268:
 #0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc9000466fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffffffff8d44cd08 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251
1 lock held by udevd/4473:
 #0: ffff888020dc1118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x162/0xa50 block/bdev.c:816
6 locks held by syz.3.2756/12187:
1 lock held by syz-executor/12201:
 #0: ffffffff8d44cd08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d44cd08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x79f/0xf10 net/core/rtnetlink.c:5695

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe1b/0xe60 kernel/hung_task.c:369
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 12187 Comm: syz.3.2756 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:mark_held_locks kernel/locking/lockdep.c:4181 [inline]
RIP: 0010:__trace_hardirqs_on_caller kernel/locking/lockdep.c:4211 [inline]
RIP: 0010:lockdep_hardirqs_on_prepare+0x1d1/0x7c0 kernel/locking/lockdep.c:4278
Code: c7 c7 e0 39 2b 8a e8 9e ae 63 08 65 ff 05 87 c2 a5 7e 48 8d b3 e8 0a 00 00 49 89 f6 49 c1 ee 03 48 ba 00 00 00 00 00 fc ff df <41> 0f b6 04 16 84 c0 0f 85 76 04 00 00 83 3e 00 0f 8e 0c 01 00 00
RSP: 0000:ffffc90000007000 EFLAGS: 00000802
RAX: 0000000000000000 RBX: ffff88802bf75940 RCX: c491b3f496b5f400
RDX: dffffc0000000000 RSI: ffff88802bf76428 RDI: ffffffff8a7a43c0
RBP: ffffc900000070b0 R08: 0000000000000027 R09: ffffffff89e000ca
R10: 0000000000000003 R11: 0000000058f53e3e R12: ffff88802be60000
R13: ffff888052fd7000 R14: 1ffff110057eec85 R15: 0000000000000286
FS:  00007f6c2bb466c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000006d2000 CR3: 000000001f983000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 trace_hardirqs_on+0x67/0x80 kernel/trace/trace_preemptirq.c:49
 kasan_quarantine_put+0xd4/0x210 mm/kasan/quarantine.c:231
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kmem_cache_free+0x8f/0x210 mm/slub.c:3520
 rds_tcp_data_recv+0x85a/0xa00 net/rds/tcp_recv.c:250
 tcp_read_sock+0x1dc/0x8c0 net/ipv4/tcp.c:1663
 rds_tcp_read_sock net/rds/tcp_recv.c:276 [inline]
 rds_tcp_data_ready+0x2b6/0x630 net/rds/tcp_recv.c:325
 tcp_rcv_established+0x1324/0x1d00 net/ipv4/tcp_input.c:6037
 tcp_v6_do_rcv+0x55b/0x11e0 net/ipv6/tcp_ipv6.c:1527
 tcp_v6_rcv+0x2268/0x2810 net/ipv6/tcp_ipv6.c:1766
 ip6_protocol_deliver_rcu+0x97b/0x1360 net/ipv6/ip6_input.c:425
 ip6_input_finish+0xa2/0x130 net/ipv6/ip6_input.c:466
 NF_HOOK+0x303/0x390 include/linux/netfilter.h:302
 NF_HOOK+0x303/0x390 include/linux/netfilter.h:302
 __netif_receive_skb_one_core net/core/dev.c:5551 [inline]
 __netif_receive_skb+0xcc/0x290 net/core/dev.c:5665
 process_backlog+0x366/0x770 net/core/dev.c:6542
 __napi_poll+0xbb/0x430 net/core/dev.c:7101
 napi_poll net/core/dev.c:7168 [inline]
 net_rx_action+0x522/0xa80 net/core/dev.c:7258
 handle_softirqs+0x336/0x830 kernel/softirq.c:576
 do_softirq+0x142/0x210 kernel/softirq.c:477
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x180/0x1c0 kernel/softirq.c:401
 rcu_read_unlock_bh include/linux/rcupdate.h:810 [inline]
 ip6_finish_output2+0x1205/0x1640 net/ipv6/ip6_output.c:133
 dst_output include/net/dst.h:452 [inline]
 NF_HOOK include/linux/netfilter.h:302 [inline]
 ip6_xmit+0x1089/0x16e0 net/ipv6/ip6_output.c:340
 inet6_csk_xmit+0x405/0x680 net/ipv6/inet6_connection_sock.c:135
 __tcp_transmit_skb+0x1ca3/0x31e0 net/ipv4/tcp_output.c:1404
 tcp_transmit_skb net/ipv4/tcp_output.c:1422 [inline]
 tcp_write_xmit+0x1a8d/0x65c0 net/ipv4/tcp_output.c:2718
 __tcp_push_pending_frames+0x92/0x250 net/ipv4/tcp_output.c:2903
 tcp_push_pending_frames include/net/tcp.h:1916 [inline]
 tcp_data_snd_check net/ipv4/tcp_input.c:5572 [inline]
 tcp_rcv_established+0xf1e/0x1d00 net/ipv4/tcp_input.c:5983
 tcp_v6_do_rcv+0x55b/0x11e0 net/ipv6/tcp_ipv6.c:1527
 sk_backlog_rcv include/net/sock.h:1080 [inline]
 __release_sock+0x1e6/0x460 net/core/sock.c:2730
 __sk_flush_backlog+0x22/0x30 net/core/sock.c:2753
 sk_flush_backlog include/net/sock.h:1177 [inline]
 tcp_sendmsg_locked+0x2832/0x3330 net/ipv4/tcp.c:1313
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1460
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 sock_write_iter+0x2a6/0x3a0 net/socket.c:1090
 call_write_iter include/linux/fs.h:2179 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x748/0xd70 fs/read_write.c:594
 ksys_write+0x153/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f6c2d8ee159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6c2bb46028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f6c2db75fa0 RCX: 00007f6c2d8ee159
RDX: 00000000fffffd9d RSI: 0000200000000200 RDI: 0000000000000003
RBP: 00007f6c2d985024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6c2db76038 R14: 00007f6c2db75fa0 R15: 00007ffcac910538
 </TASK>