INFO: task udevd:19780 blocked for more than 143 seconds. Not tainted 6.6.101-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:25352 pid:19780 ppid:5160 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 io_schedule+0x80/0xd0 kernel/sched/core.c:9023 folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329 folio_put_wait_locked mm/filemap.c:1493 [inline] do_read_cache_folio+0x1c0/0x7e0 mm/filemap.c:3771 read_mapping_folio include/linux/pagemap.h:898 [inline] read_part_sector+0xd2/0x350 block/partitions/core.c:718 adfspart_check_POWERTEC+0x8d/0xf00 block/partitions/acorn.c:454 check_partition block/partitions/core.c:138 [inline] blk_add_partitions block/partitions/core.c:600 [inline] bdev_disk_changed+0x73a/0x1410 block/partitions/core.c:689 blkdev_get_whole+0x30d/0x390 block/bdev.c:655 blkdev_get_by_dev+0x279/0x600 block/bdev.c:797 blkdev_open+0x152/0x360 block/fops.c:589 do_dentry_open+0x8c6/0x1500 fs/open.c:929 do_open fs/namei.c:3632 [inline] path_openat+0x274b/0x3190 fs/namei.c:3789 do_filp_open+0x1c5/0x3d0 fs/namei.c:3816 do_sys_openat2+0x12c/0x1c0 fs/open.c:1419 do_sys_open fs/open.c:1434 [inline] __do_sys_openat fs/open.c:1450 [inline] __se_sys_openat fs/open.c:1445 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1445 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f81230a7407 RSP: 002b:00007fffc7879f70 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f8123863880 RCX: 00007f81230a7407 RDX: 00000000000a0800 RSI: 0000562ae79697f0 RDI: ffffffffffffff9c RBP: 0000562ae793e910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000562ae795da10 R13: 0000562ae7956420 R14: 0000000000000000 R15: 0000562ae795da10 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2fba0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2fba0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2fba0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 3 locks held by kworker/u4:11/3513: #0: ffff8880b8e3c458 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:566 #1: ffffc9000c717d00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000c717d00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff8880b8e297d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:999 2 locks held by getty/5550: #0: ffff88802dbfa0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 1 lock held by syz-executor/5777: #0: ffff8880b8e3c458 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:566 2 locks held by kworker/u4:13/6294: #0: ffff8880b8e3c458 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:566 #1: ffff8880b8e288c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39c/0x6d0 kernel/sched/psi.c:998 2 locks held by kworker/0:12/6556: #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90019477d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90019477d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 1 lock held by udevd/19780: #0: ffff888021dd34c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788 4 locks held by kvm-nx-lpage-re/22555: #0: ffffffff8cd59ac8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:369 [inline] #0: ffffffff8cd59ac8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_attach_task_all+0x26/0xe0 kernel/cgroup/cgroup-v1.c:61 #1: ffffffff8cbcafd0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock+0x11/0x30 kernel/cgroup/cgroup.c:2391 #2: ffffffff8cd59cb0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_task_all+0x30/0xe0 kernel/cgroup/cgroup-v1.c:62 #3: ffffffff8cd35b78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #3: ffffffff8cd35b78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004 1 lock held by syz.1.3963/22560: 2 locks held by dhcpcd/22569: #0: ffff88806a512130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1731 [inline] #0: ffff88806a512130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcc0 net/packet/af_packet.c:3258 #1: ffffffff8cd35b78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #1: ffffffff8cd35b78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004 1 lock held by dhcpcd/22570: #0: ffff888031a22130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1731 [inline] #0: ffff888031a22130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcc0 net/packet/af_packet.c:3258 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.6.101-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5149 Comm: klogd Not tainted 6.6.101-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:206 [inline] RIP: 0010:unwind_next_frame+0x1f2/0x2970 arch/x86/kernel/unwind_orc.c:494 Code: ff 00 00 00 81 40 0f 92 c5 4c 89 ff 48 c7 c6 00 00 a0 8a e8 00 f3 4a 00 49 81 ff 00 00 a0 8a 0f 93 c0 40 08 e8 4c 89 7c 24 48 <0f> 85 d7 00 00 00 49 29 df 49 c1 ef 08 8b 05 d3 6b 42 0b 48 89 44 RSP: 0018:ffffc90003287378 EFLAGS: 00000246 RAX: ffffffff813aa400 RBX: ffffffff81000000 RCX: ffff88807df20000 RDX: 0000000000000000 RSI: ffffffff8aa00000 RDI: ffffffff885fcad9 RBP: ffffc90003287400 R08: ffffc90003287510 R09: 0000000000000008 R10: 0000000000000004 R11: 0000000000000000 R12: ffffc90003287448 R13: dffffc0000000000 R14: ffffc9000328747d R15: ffffffff885fcad9 FS: 00007f5c706c2c80(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055fffc52ba40 CR3: 000000002f2d3000 CR4: 00000000003526e0 Call Trace: arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc_node_track_caller+0xb2/0x230 mm/slab_common.c:1027 kmalloc_reserve+0x117/0x260 net/core/skbuff.c:581 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1284 [inline] alloc_skb_with_frags+0xca/0x7c0 net/core/skbuff.c:6328 sock_alloc_send_pskb+0x857/0x990 net/core/sock.c:2799 unix_dgram_sendmsg+0x5a1/0x1720 net/unix/af_unix.c:2001 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x46a/0x620 net/socket.c:2201 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0xde/0xf0 net/socket.c:2209 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f5c70812407 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:00007ffe2f555550 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f5c706c2c80 RCX: 00007f5c70812407 RDX: 000000000000004b RSI: 00007ffe2f555690 RDI: 0000000000000003 RBP: 00007ffe2f555ac0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffe2f555ad8 R13: 00007ffe2f555690 R14: 0000000000000030 R15: 00007ffe2f555690