INFO: task udevd:7892 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:21832 pid:7892 tgid:7892 ppid:5200 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 io_schedule+0x80/0xd0 kernel/sched/core.c:7789 folio_wait_bit_common+0x6b0/0xb80 mm/filemap.c:1323 folio_put_wait_locked mm/filemap.c:1487 [inline] do_read_cache_folio+0x1ad/0x590 mm/filemap.c:4078 read_mapping_folio include/linux/pagemap.h:1017 [inline] read_part_sector+0xb6/0x2b0 block/partitions/core.c:722 adfspart_check_POWERTEC+0x8c/0xf30 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+0x75f/0x14b0 block/partitions/core.c:693 blkdev_get_whole+0x380/0x510 block/bdev.c:765 bdev_open+0x31e/0xd30 block/bdev.c:974 blkdev_open+0x457/0x600 block/fops.c:698 do_dentry_open+0x7ce/0x1420 fs/open.c:962 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:4628 [inline] path_openat+0x340e/0x3dd0 fs/namei.c:4787 do_filp_open+0x1fa/0x410 fs/namei.c:4814 do_sys_openat2+0x121/0x200 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+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2f90ea7407 RSP: 002b:00007ffc1ca29800 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f2f915d2880 RCX: 00007f2f90ea7407 RDX: 00000000000a0800 RSI: 000056292b79c720 RDI: ffffffffffffff9c RBP: 000056292b781910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000056292b79ef10 R13: 000056292b78f190 R14: 0000000000000000 R15: 000056292b79ef10 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df41a20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df41a20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df41a20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 1 lock held by udevd/5200: 2 locks held by getty/5589: #0: ffff88802f57b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211 5 locks held by kworker/u8:17/6202: #0: ffff88801aa9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88801aa9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000b8e7b80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000b8e7b80 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7a0 net/core/net_namespace.c:670 #3: ffffffff8f311c88 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff8f311c88 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990 net/core/net_namespace.c:248 #4: ffffffff8df47578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #4: ffffffff8df47578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:956 1 lock held by udevd/7892: #0: ffff88814139b358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962 3 locks held by kworker/u8:19/8059: #0: ffff88813ff29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000c0cfb80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000c0cfb80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffffffff8f311c88 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 4 locks held by udevd/9243: 2 locks held by syz.1.2853/17226: #0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577 #1: ffff888032decf98 (&device->compat_devs_mutex){+.+.}-{4:4}, at: remove_one_compat_dev drivers/infiniband/core/device.c:1034 [inline] #1: ffff888032decf98 (&device->compat_devs_mutex){+.+.}-{4:4}, at: rdma_dev_exit_net+0x1ac/0x340 drivers/infiniband/core/device.c:1176 5 locks held by syz.1.2853/17227: #0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577 #1: ffffffff8f078c50 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x1f5/0x2f0 drivers/infiniband/core/device.c:1215 #2: ffffffff8f078e10 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x22d/0x2f0 drivers/infiniband/core/device.c:1220 #3: ffff88804a048f98 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0xf0/0x650 drivers/infiniband/core/device.c:979 #4: ffffffff8f311c88 (rtnl_mutex){+.+.}-{4:4}, at: ib_get_eth_speed+0x151/0x7b0 drivers/infiniband/core/verbs.c:1998 4 locks held by syz-executor/17228: #0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577 #1: ffffffff8f078c50 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x1f5/0x2f0 drivers/infiniband/core/device.c:1215 #2: ffffffff8f078e10 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x22d/0x2f0 drivers/infiniband/core/device.c:1220 #3: ffff88804a048f98 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0xf0/0x650 drivers/infiniband/core/device.c:979 6 locks held by syz.2.2860/17258: #0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577 #1: ffffffff8f078c50 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x1f5/0x2f0 drivers/infiniband/core/device.c:1215 #2: ffffffff8f078e10 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x22d/0x2f0 drivers/infiniband/core/device.c:1220 #3: ffff888032decf98 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0xf0/0x650 drivers/infiniband/core/device.c:979 #4: ffff888032ded290 (&rxe->usdev_lock){+.+.}-{4:4}, at: rxe_query_port+0x7e/0x3d0 drivers/infiniband/sw/rxe/rxe_verbs.c:61 #5: ffffffff8f311c88 (rtnl_mutex){+.+.}-{4:4}, at: ib_get_eth_speed+0x151/0x7b0 drivers/infiniband/core/verbs.c:1998 2 locks held by syz.4.2862/17262: #0: ffffffff8f3798f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8f311c88 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:17932 2 locks held by syz.4.2862/17265: #0: ffff8880446e7508 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #0: ffff8880446e7508 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff8880446e7508 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455 #1: ffffffff8f311c88 (rtnl_mutex){+.+.}-{4:4}, at: raw_release+0x1bc/0xa10 net/can/raw.c:418 1 lock held by syz.0.2863/17263: #0: ffffffff8f311c88 (rtnl_mutex){+.+.}-{4:4}, at: ppp_release+0x87/0x1f0 drivers/net/ppp/ppp_generic.c:413 1 lock held by syz.0.2863/17264: #0: ffffffff8f311c88 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f311c88 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [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+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 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: 9243 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:unwind_next_frame+0xd2f/0x23d0 arch/x86/include/asm/stacktrace.h:-1 Code: 49 8d 5e 10 49 89 dd 49 c1 ed 03 48 b8 00 00 00 00 00 fc ff df 41 80 7c 05 00 00 74 08 48 89 df e8 86 c2 b3 00 48 89 5c 24 60 <4c> 89 64 24 18 49 8d 5c 24 f8 4d 8b 66 10 48 b8 00 00 00 00 00 fc RSP: 0018:ffffc90000a08918 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffc90000a089f8 RCX: ffffffff8f98ffa0 RDX: ffffffff9013ed50 RSI: 0000000000000002 RDI: ffffffff8bc08300 RBP: 1ffff9200014113e R08: 0000000000000003 R09: ffffffff8df41a20 R10: ffffc90000a08a38 R11: ffffffff81ada120 R12: ffffc90000a08ff8 R13: 1ffff9200014113f R14: ffffc90000a089e8 R15: ffffc90000a01000 FS: 00007f2f915d2880(0000) GS:ffff888125f35000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055afcf90a000 CR3: 0000000077c6e000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:339 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270 sigqueue_alloc kernel/signal.c:455 [inline] __send_signal_locked+0x22a/0xeb0 kernel/signal.c:1087 do_send_sig_info kernel/signal.c:1269 [inline] group_send_sig_info+0x1fd/0x260 kernel/signal.c:1419 do_bpf_send_signal+0xa9/0x1c0 kernel/trace/bpf_trace.c:813 irq_work_single+0xe1/0x240 kernel/irq_work.c:221 irq_work_run_list kernel/irq_work.c:252 [inline] irq_work_run+0x155/0x2f0 kernel/irq_work.c:261 __sysvec_irq_work+0x98/0x3a0 arch/x86/kernel/irq_work.c:22 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x9e/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:733 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:37 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:139 [inline] RIP: 0010:wrmsrq arch/x86/include/asm/msr.h:199 [inline] RIP: 0010:native_apic_msr_write+0x39/0x50 arch/x86/include/asm/apic.h:212 Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 cc cc cc cc cc f3 0f 1e fa 89 f6 31 d2 e9 72 01 56 03 66 RSP: 0018:ffffc90002f37468 EFLAGS: 00000246 RAX: 00000000000000f6 RBX: 0000000000000200 RCX: 000000000000083f RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f RBP: ffffc90002f37540 R08: ffffc90002f374c7 R09: 1ffff920005e6e98 R10: dffffc0000000000 R11: fffff520005e6e99 R12: ffff8880b8731c01 R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880b8731c70 __apic_send_IPI_self arch/x86/include/asm/apic.h:459 [inline] arch_irq_work_raise+0x6d/0x80 arch/x86/kernel/irq_work.c:31 irq_work_raise kernel/irq_work.c:84 [inline] __irq_work_queue_local+0x1d7/0x530 kernel/irq_work.c:112 irq_work_queue+0x99/0x140 kernel/irq_work.c:124 bpf_send_signal_common+0x3b4/0x540 kernel/trace/bpf_trace.c:871 ____bpf_send_signal kernel/trace/bpf_trace.c:880 [inline] bpf_send_signal+0x1d/0x30 kernel/trace/bpf_trace.c:878 bpf_prog_8ecd41c4ac539703+0x25/0x4c bpf_dispatcher_nop_func include/linux/bpf.h:1378 [inline] __bpf_prog_run include/linux/filter.h:723 [inline] bpf_prog_run include/linux/filter.h:730 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline] bpf_trace_run2+0x284/0x4c0 kernel/trace/bpf_trace.c:2116 __bpf_trace_contention_end+0xdc/0x130 include/trace/events/lock.h:122 __traceiter_contention_end+0x7a/0xb0 include/trace/events/lock.h:122 __do_trace_contention_end include/trace/events/lock.h:122 [inline] trace_contention_end+0xde/0x100 include/trace/events/lock.h:122 __mutex_lock_common kernel/locking/mutex.c:623 [inline] __mutex_lock+0x32b/0x1350 kernel/locking/mutex.c:776 ep_send_events fs/eventpoll.c:1781 [inline] ep_try_send_events+0x197/0xf40 fs/eventpoll.c:1905 ep_poll fs/eventpoll.c:1970 [inline] do_epoll_wait+0x53f/0xf30 fs/eventpoll.c:2461 __do_sys_epoll_wait fs/eventpoll.c:2469 [inline] __se_sys_epoll_wait fs/eventpoll.c:2464 [inline] __x64_sys_epoll_wait+0x1be/0x210 fs/eventpoll.c:2464 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2f90ea7407 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:00007ffc1ca29850 EFLAGS: 00000202 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 00007f2f915d2880 RCX: 00007f2f90ea7407 RDX: 0000000000000004 RSI: 00007ffc1ca298e0 RDI: 0000000000000004 RBP: 000056292b781910 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000202 R12: 00007ffc1ca298ec R13: 00007ffc1ca298e0 R14: 0000000000000000 R15: 0000000000000001