INFO: task udevd:12992 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:22104 pid:12992 tgid:12992 ppid:5170 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x1472/0x4fe0 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x164/0x360 kernel/sched/core.c:6964 io_schedule+0x80/0xe0 kernel/sched/core.c:7791 folio_wait_bit_common+0x6dd/0xbc0 mm/filemap.c:1323 folio_put_wait_locked mm/filemap.c:1487 [inline] do_read_cache_folio+0x1a7/0x560 mm/filemap.c:4078 read_mapping_folio include/linux/pagemap.h:1028 [inline] read_part_sector+0xb8/0x2b0 block/partitions/core.c:722 adfspart_check_POWERTEC+0x92/0xef0 block/partitions/acorn.c:454 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x765/0x14c0 block/partitions/core.c:693 blkdev_get_whole+0x2e5/0x480 block/bdev.c:765 bdev_open+0x31e/0xcc0 block/bdev.c:974 blkdev_open+0x485/0x620 block/fops.c:698 do_dentry_open+0x7d0/0x1270 fs/open.c:962 vfs_open+0x3b/0x350 fs/open.c:1094 do_open fs/namei.c:4637 [inline] path_openat+0x34c9/0x3e70 fs/namei.c:4796 do_filp_open+0x22d/0x490 fs/namei.c:4823 do_sys_openat2+0x12f/0x220 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4ea03bd407 RSP: 002b:00007ffc87318370 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f4ea02cf880 RCX: 00007f4ea03bd407 RDX: 00000000000a0800 RSI: 0000565043b034f0 RDI: ffffffffffffff9c RBP: 0000565043ae2910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000565043af5e20 R13: 0000565043af0190 R14: 0000000000000000 R15: 0000565043af5e20 INFO: task udevd:13063 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:22312 pid:13063 tgid:13063 ppid:5170 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x1472/0x4fe0 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x164/0x360 kernel/sched/core.c:6964 io_schedule+0x80/0xe0 kernel/sched/core.c:7791 folio_wait_bit_common+0x6dd/0xbc0 mm/filemap.c:1323 folio_put_wait_locked mm/filemap.c:1487 [inline] do_read_cache_folio+0x1a7/0x560 mm/filemap.c:4078 read_mapping_folio include/linux/pagemap.h:1028 [inline] read_part_sector+0xb8/0x2b0 block/partitions/core.c:722 adfspart_check_POWERTEC+0x92/0xef0 block/partitions/acorn.c:454 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x765/0x14c0 block/partitions/core.c:693 blkdev_get_whole+0x2e5/0x480 block/bdev.c:765 bdev_open+0x31e/0xcc0 block/bdev.c:974 blkdev_open+0x485/0x620 block/fops.c:698 do_dentry_open+0x7d0/0x1270 fs/open.c:962 vfs_open+0x3b/0x350 fs/open.c:1094 do_open fs/namei.c:4637 [inline] path_openat+0x34c9/0x3e70 fs/namei.c:4796 do_filp_open+0x22d/0x490 fs/namei.c:4823 do_sys_openat2+0x12f/0x220 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4ea03bd407 RSP: 002b:00007ffc87318370 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f4ea02cf880 RCX: 00007f4ea03bd407 RDX: 00000000000a0800 RSI: 0000565043af38a0 RDI: ffffffffffffff9c RBP: 0000565043ae2910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000565043af5e20 R13: 0000565043af0190 R14: 0000000000000000 R15: 0000565043af5e20 INFO: task udevd:13081 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:22280 pid:13081 tgid:13081 ppid:5170 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x1472/0x4fe0 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x164/0x360 kernel/sched/core.c:6964 io_schedule+0x80/0xe0 kernel/sched/core.c:7791 folio_wait_bit_common+0x6dd/0xbc0 mm/filemap.c:1323 folio_put_wait_locked mm/filemap.c:1487 [inline] do_read_cache_folio+0x1a7/0x560 mm/filemap.c:4078 read_mapping_folio include/linux/pagemap.h:1028 [inline] read_part_sector+0xb8/0x2b0 block/partitions/core.c:722 adfspart_check_POWERTEC+0x92/0xef0 block/partitions/acorn.c:454 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x765/0x14c0 block/partitions/core.c:693 blkdev_get_whole+0x2e5/0x480 block/bdev.c:765 bdev_open+0x31e/0xcc0 block/bdev.c:974 blkdev_open+0x485/0x620 block/fops.c:698 do_dentry_open+0x7d0/0x1270 fs/open.c:962 vfs_open+0x3b/0x350 fs/open.c:1094 do_open fs/namei.c:4637 [inline] path_openat+0x34c9/0x3e70 fs/namei.c:4796 do_filp_open+0x22d/0x490 fs/namei.c:4823 do_sys_openat2+0x12f/0x220 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4ea03bd407 RSP: 002b:00007ffc87318370 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f4ea02cf880 RCX: 00007f4ea03bd407 RDX: 00000000000a0800 RSI: 0000565043affe00 RDI: ffffffffffffff9c RBP: 0000565043ae2910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000565043afae00 R13: 0000565043af0190 R14: 0000000000000000 R15: 0000565043afae00 INFO: task udevd:13261 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:21272 pid:13261 tgid:13261 ppid:5170 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x1472/0x4fe0 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x164/0x360 kernel/sched/core.c:6964 io_schedule+0x80/0xe0 kernel/sched/core.c:7791 folio_wait_bit_common+0x6dd/0xbc0 mm/filemap.c:1323 folio_put_wait_locked mm/filemap.c:1487 [inline] do_read_cache_folio+0x1a7/0x560 mm/filemap.c:4078 read_mapping_folio include/linux/pagemap.h:1028 [inline] read_part_sector+0xb8/0x2b0 block/partitions/core.c:722 adfspart_check_POWERTEC+0x92/0xef0 block/partitions/acorn.c:454 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x765/0x14c0 block/partitions/core.c:693 blkdev_get_whole+0x2e5/0x480 block/bdev.c:765 bdev_open+0x31e/0xcc0 block/bdev.c:974 blkdev_open+0x485/0x620 block/fops.c:698 do_dentry_open+0x7d0/0x1270 fs/open.c:962 vfs_open+0x3b/0x350 fs/open.c:1094 do_open fs/namei.c:4637 [inline] path_openat+0x34c9/0x3e70 fs/namei.c:4796 do_filp_open+0x22d/0x490 fs/namei.c:4823 do_sys_openat2+0x12f/0x220 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4ea03bd407 RSP: 002b:00007ffc87318370 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f4ea02cf880 RCX: 00007f4ea03bd407 RDX: 00000000000a0800 RSI: 0000565043aea880 RDI: ffffffffffffff9c RBP: 0000565043ae2910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000565043ae2fb0 R13: 0000565043af0190 R14: 0000000000000000 R15: 0000565043ae2fb0 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8dbc77c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8dbc77c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8dbc77c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:3/44: #0: ffff88801aad6138 ((wq_completion)pm){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88801aad6138 ((wq_completion)pm){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc90000b67bc0 ((work_completion)(&hcd->wakeup_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90000b67bc0 ((work_completion)(&hcd->wakeup_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffff8880299eb188 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff8880299eb188 (&dev->mutex){....}-{4:4}, at: usb_remote_wakeup+0x23/0x120 drivers/usb/core/hub.c:3886 2 locks held by getty/5556: #0: ffff8880312c70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 5 locks held by kworker/u8:20/12294: 1 lock held by udevd/12992: #0: ffff8880253124c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:962 1 lock held by udevd/13063: #0: ffff8880250f64c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:962 1 lock held by udevd/13081: #0: ffff8880251664c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:962 1 lock held by udevd/13261: #0: ffff88802518e4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:962 9 locks held by syz-executor/19932: 2 locks held by syz.8.3896/21361: #0: ffff88802572a2f8 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff88802572a2f8 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff88802572a2f8 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455 #1: ffff88802958c358 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1700 [inline] #1: ffff88802958c358 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: pptp_release+0x52/0x360 drivers/net/ppp/pptp.c:513 3 locks held by syz.8.3896/21372: 3 locks held by syz.6.3898/21367: #0: ffff88803f6870f8 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff88803f6870f8 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff88803f6870f8 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455 #1: ffffffff8efa7ac0 ((netlink_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x54/0x90 kernel/notifier.c:379 #2: ffff8880819b08c8 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nft_rcv_nl_event+0x13d/0xdb0 net/netfilter/nf_tables_api.c:12136 1 lock held by syz.6.3898/21374: 1 lock held by syz.1.3899/21376: #0: ffffffff8ef3ea78 (bpf_dispatcher_xdp.mutex){+.+.}-{4:4}, at: bpf_dispatcher_change_prog+0xc6/0xd70 kernel/bpf/dispatcher.c:146 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline] watchdog+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 08 50 02 e9 03 c2 03 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d e3 11 1c 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc900001d7e20 EFLAGS: 00000242 RAX: 00000000033a7d19 RBX: ffffffff81981bfd RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d33ad09 RDI: ffffffff8b85e800 RBP: ffffc900001d7f10 R08: ffff8880b8933c5b R09: 1ffff1101712678b R10: dffffc0000000000 R11: ffffed101712678c R12: ffffffff8f47de70 R13: 1ffff110038dfb58 R14: 0000000000000001 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881266c9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f98b35b0218 CR3: 000000007212c000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1bd/0x500 kernel/sched/idle.c:332 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:430 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147