INFO: task udevd:8606 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:25344 pid:8606 ppid:3639 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 io_schedule+0x7c/0xd0 kernel/sched/core.c:8798 folio_wait_bit_common+0x877/0xfa0 mm/filemap.c:1324 folio_put_wait_locked mm/filemap.c:1493 [inline] do_read_cache_folio+0x1a7/0x790 mm/filemap.c:3641 read_mapping_folio include/linux/pagemap.h:799 [inline] read_part_sector+0xce/0x360 block/partitions/core.c:724 adfspart_check_POWERTEC+0xc0/0x890 block/partitions/acorn.c:454 check_partition block/partitions/core.c:146 [inline] blk_add_partitions block/partitions/core.c:609 [inline] bdev_disk_changed+0x7f9/0x1450 block/partitions/core.c:695 blkdev_get_whole+0x2e8/0x370 block/bdev.c:704 blkdev_get_by_dev+0x32e/0xa60 block/bdev.c:841 blkdev_open+0x119/0x2d0 block/fops.c:500 do_dentry_open+0x7dd/0x10b0 fs/open.c:882 do_open fs/namei.c:3634 [inline] path_openat+0x2674/0x2f10 fs/namei.c:3791 do_filp_open+0x1ee/0x420 fs/namei.c:3818 do_sys_openat2+0x14b/0x4f0 fs/open.c:1320 do_sys_open fs/open.c:1336 [inline] __do_sys_openat fs/open.c:1352 [inline] __se_sys_openat fs/open.c:1347 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1347 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fe5734a7407 RSP: 002b:00007ffca4dbbb10 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fe573c19880 RCX: 00007fe5734a7407 RDX: 00000000000a0800 RSI: 00005598c2e2bdf0 RDI: ffffffffffffff9c RBP: 00005598c2e0a910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00005598c2e22e00 R13: 00005598c2e22410 R14: 0000000000000000 R15: 00005598c2e22e00 Showing all locks held in the system: 2 locks held by kworker/u4:0/9: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2e4f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2ed10 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by getty/4029: #0: ffff8880302ed098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198 1 lock held by udevd/8606: #0: ffff888024cf14c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12a/0xa60 block/bdev.c:832 2 locks held by dhcpcd/13726: #0: ffff8880735a4130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline] #0: ffff8880735a4130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3255 #1: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #1: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962 ============================================= 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 05/09/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf0e/0xf50 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3628 Comm: klogd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:list_empty include/linux/list.h:292 [inline] RIP: 0010:prepare_to_wait_exclusive+0x66/0x210 kernel/sched/wait.c:286 Code: e8 af b2 d3 08 48 89 44 24 10 49 8d 6c 24 18 49 89 ed 49 c1 ed 03 43 80 7c 3d 00 00 74 08 48 89 ef e8 4e 0c 72 00 48 8b 45 00 <48> 39 e8 74 77 31 ed f6 c3 cc 0f 85 6a 01 00 00 4c 8d 25 00 00 00 RSP: 0018:ffffc900032979d0 EFLAGS: 00000046 RAX: ffffc90003297a78 RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc900032978c0 RBP: ffffc90003297a78 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000652f18 R12: ffffc90003297a60 R13: 1ffff92000652f4f R14: ffff88807e1bbec0 R15: dffffc0000000000 FS: 00007f96714dfc80(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005612de5a0168 CR3: 000000007e577000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unix_wait_for_peer+0x105/0x2e0 net/unix/af_unix.c:1440 unix_dgram_sendmsg+0xeba/0x16f0 net/unix/af_unix.c:2049 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] __sys_sendto+0x497/0x650 net/socket.c:2153 __do_sys_sendto net/socket.c:2165 [inline] __se_sys_sendto net/socket.c:2161 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2161 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f967162f407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffcb65e5a10 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f96714dfc80 RCX: 00007f967162f407 RDX: 0000000000000051 RSI: 00007ffcb65e5b50 RDI: 0000000000000003 RBP: 00007ffcb65e5f80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffcb65e5f98 R13: 00007ffcb65e5b50 R14: 0000000000000036 R15: 00007ffcb65e5b50