INFO: task udevd:15137 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:24112 pid:15137 ppid:3640 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 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+0x70a/0xfa0 mm/filemap.c:1324 folio_put_wait_locked mm/filemap.c:1493 [inline] do_read_cache_folio+0x1a9/0x760 mm/filemap.c:3641 read_mapping_folio include/linux/pagemap.h:799 [inline] read_part_sector+0xce/0x350 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+0x7d9/0x14a0 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+0x11e/0x2e0 block/fops.c:500 do_dentry_open+0x7e9/0x10d0 fs/open.c:882 do_open fs/namei.c:3634 [inline] path_openat+0x2635/0x2ee0 fs/namei.c:3791 do_filp_open+0x1f1/0x430 fs/namei.c:3818 do_sys_openat2+0x150/0x4b0 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: 0033:0x7fbaaf6a7407 RSP: 002b:00007ffe692fbc60 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fbaafd46880 RCX: 00007fbaaf6a7407 RDX: 00000000000a0800 RSI: 0000557dd6c7b0f0 RDI: ffffffffffffff9c RBP: 0000557dd6c63910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000557dd6c864d0 R13: 0000557dd6c7b410 R14: 0000000000000000 R15: 0000557dd6c864d0 INFO: task udevd:15348 blocked for more than 146 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:25136 pid:15348 ppid:3640 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 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+0x70a/0xfa0 mm/filemap.c:1324 folio_put_wait_locked mm/filemap.c:1493 [inline] do_read_cache_folio+0x1a9/0x760 mm/filemap.c:3641 read_mapping_folio include/linux/pagemap.h:799 [inline] read_part_sector+0xce/0x350 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+0x7d9/0x14a0 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+0x11e/0x2e0 block/fops.c:500 do_dentry_open+0x7e9/0x10d0 fs/open.c:882 do_open fs/namei.c:3634 [inline] path_openat+0x2635/0x2ee0 fs/namei.c:3791 do_filp_open+0x1f1/0x430 fs/namei.c:3818 do_sys_openat2+0x150/0x4b0 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: 0033:0x7fbaaf6a7407 RSP: 002b:00007ffe692fbc60 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fbaafd46880 RCX: 00007fbaaf6a7407 RDX: 00000000000a0800 RSI: 0000557dd6c7b0f0 RDI: ffffffffffffff9c RBP: 0000557dd6c63910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000557dd6c86a50 R13: 0000557dd6c7b410 R14: 0000000000000000 R15: 0000557dd6c86a50 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2e770 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2ef90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8cb2dde0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2dde0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2dde0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by udevd/3640: 2 locks held by getty/4029: #0: ffff88814d2c2098 (&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+0x429/0x1390 drivers/tty/n_tty.c:2198 2 locks held by kworker/u4:10/5049: 1 lock held by udevd/15137: #0: ffff88802471d4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x13d/0xa60 block/bdev.c:832 1 lock held by udevd/15348: #0: ffff888024f3b4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x13d/0xa60 block/bdev.c:832 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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+0xeee/0xf30 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5049 Comm: kworker/u4:10 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: bat_events batadv_nc_worker RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3719 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3738 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3793 [inline] RIP: 0010:__lock_acquire+0x170f/0x7d10 kernel/locking/lockdep.c:5049 Code: 18 e8 75 28 6f 00 48 8b 7c 24 28 48 8b 74 24 20 48 ba 00 00 00 00 00 fc ff df e9 65 ff ff ff 4c 8d 73 18 4c 89 f0 48 c1 e8 03 <42> 80 3c 00 00 74 12 4c 89 f7 e8 52 28 6f 00 49 b8 00 00 00 00 00 RSP: 0018:ffffc90003a67780 EFLAGS: 00000802 RAX: 1ffffffff217066b RBX: ffffffff90b83340 RCX: ffffffff81646700 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90afd318 RBP: ffffc90003a679d0 R08: dffffc0000000000 R09: 1ffffffff215fa63 R10: dffffc0000000000 R11: fffffbfff215fa64 R12: ffffffff90730098 R13: 00000000773c62d9 R14: ffffffff90b83358 R15: ffff888075e6a890 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4eb41ea2f8 CR3: 000000001fb88000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x32/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] batadv_nc_purge_paths+0xe7/0x3b0 net/batman-adv/network-coding.c:442 batadv_nc_worker+0x365/0x600 net/batman-adv/network-coding.c:722 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295