INFO: task syz-executor:21747 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21320 pid:21747 tgid:21747 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5310 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 bit_wait+0x11/0xd0 kernel/sched/wait_bit.c:240 __wait_on_bit+0xb9/0x310 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit include/linux/wait_bit.h:77 [inline] gfs2_glock_wait+0xbd/0x2a0 fs/gfs2/glock.c:1269 gfs2_glock_nq_init fs/gfs2/glock.h:253 [inline] __gfs2_lookup+0x134/0x2a0 fs/gfs2/inode.c:999 __lookup_slow+0x2b7/0x410 fs/namei.c:1916 lookup_slow+0x53/0x70 fs/namei.c:1933 walk_component fs/namei.c:2279 [inline] lookup_last fs/namei.c:2780 [inline] path_lookupat+0x3f5/0x8c0 fs/namei.c:2804 filename_lookup+0x256/0x5d0 fs/namei.c:2833 user_path_at+0x40/0x160 fs/namei.c:3612 ksys_umount fs/namespace.c:2052 [inline] __do_sys_umount fs/namespace.c:2060 [inline] __se_sys_umount fs/namespace.c:2058 [inline] __x64_sys_umount+0xf6/0x170 fs/namespace.c:2058 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4c40d9c117 RSP: 002b:00007fffd34c7288 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007f4c40e0471f RCX: 00007f4c40d9c117 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffd34c7340 RBP: 00007fffd34c7340 R08: 0000000000000000 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffd34c8430 R13: 00007f4c40e0471f R14: 0000000000178719 R15: 00007fffd34ca5f0 Showing all locks held in the system: 2 locks held by ksoftirqd/0/15: 1 lock held by khungtaskd/31: #0: ffffffff8e760320 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e760320 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e760320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:2/36: #0: ffff888031d5f948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254 #1: ffffc90000ac7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255 #2: ffffffff8fbc7d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8fbc7d08 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0 net/ipv6/addrconf.c:4199 2 locks held by getty/5578: #0: ffff888036eda0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 3 locks held by kworker/u8:5/18116: #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254 #1: ffffc9000d36fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255 #2: ffffffff8fbc7d08 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 6 locks held by kworker/0:10/21686: #0: ffff888021ed2948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254 #1: ffffc9000c197c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255 #2: ffff88802a26f198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88802a26f198 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899 #3: ffff88802b50f198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff88802b50f198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1008 #4: ffff8880312a4160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff8880312a4160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1008 #5: ffffffff8fb2f468 (register_mutex#6){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #5: ffffffff8fb2f468 (register_mutex#6){+.+.}-{4:4}, at: usb_audio_probe+0x82e/0x2330 sound/usb/card.c:950 1 lock held by syz-executor/21747: #0: ffff88805bef4a28 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline] #0: ffff88805bef4a28 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1932 4 locks held by udevd/22752: #0: ffff88805b852540 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:183 #1: ffff88807e7c0488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffff88805a5c4b48 (kn->active#32){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88805a5c4b48 (kn->active#32){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173 #3: ffff88802b50f198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline] #3: ffff88802b50f198 (&dev->mutex){....}-{4:4}, at: serial_show+0x26/0xa0 drivers/usb/core/sysfs.c:143 1 lock held by syz-executor/24748: #0: ffffffff8fbc7d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8fbc7d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x722/0xbe0 net/core/rtnetlink.c:6964 4 locks held by syz.2.3994/25185: 2 locks held by syz.1.3995/25212: #0: ffffffff8fbc7d08 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8fbc7d08 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 #1: ffffffff8e7665b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8e7665b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 4 locks held by syz.7.3996/25208: #0: ffff88804de81908 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #0: ffff88804de81908 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: __sock_release+0x89/0x250 net/socket.c:665 #1: ffffffff8fc341f0 ((netlink_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x54/0x90 kernel/notifier.c:379 #2: ffff88802a46c4d8 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nft_rcv_nl_event+0x13d/0xdb0 net/netfilter/nf_tables_api.c:12145 #3: ffffffff8e7665b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #3: ffffffff8e7665b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 1 lock held by dhcpcd-run-hook/25224: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 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:347 [inline] watchdog+0x103d/0x1090 kernel/hung_task.c:516 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 25208 Comm: syz.7.3996 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:97 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:115 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:140 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline] RIP: 0010:kasan_check_range+0x8a/0x2c0 mm/kasan/generic.c:200 Code: 4d 89 c1 49 c1 e9 03 48 bb 01 00 00 00 00 fc ff df 4d 8d 34 19 4d 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 3d 01 00 00 <4c> 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00 0f 85 9e 01 00 00 49 ff c3 RSP: 0018:ffffc9000c346f48 EFLAGS: 00000202 RAX: ffffffff82051301 RBX: dffffc0000000001 RCX: ffffffff820513de RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffea0005b61874 RBP: ffffc9000c347090 R08: ffffea0005b61877 R09: 1ffffd4000b6c30e R10: dffffc0000000000 R11: fffff94000b6c30e R12: 0000000000000001 R13: ffffea0005b61840 R14: fffff94000b6c30f R15: 1ffffd4000b6c30e FS: 0000000000000000(0000) GS:ffff88812556a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005633d8b30950 CR3: 000000001efac000 CR4: 00000000003526f0 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:112 [inline] atomic_sub_and_test include/linux/atomic/atomic-instrumented.h:1365 [inline] page_ref_sub_and_test include/linux/page_ref.h:177 [inline] folio_ref_sub_and_test include/linux/page_ref.h:186 [inline] folios_put_refs+0x26e/0x8d0 mm/swap.c:974 free_pages_and_swap_cache+0x2e7/0x5b0 mm/swap_state.c:423 __tlb_batch_free_encoded_pages mm/mmu_gather.c:137 [inline] tlb_batch_pages_flush mm/mmu_gather.c:150 [inline] tlb_flush_mmu_free mm/mmu_gather.c:397 [inline] tlb_flush_mmu+0x6d3/0xa30 mm/mmu_gather.c:404 zap_pte_range mm/memory.c:1970 [inline] zap_pmd_range mm/memory.c:2023 [inline] zap_pud_range mm/memory.c:2051 [inline] zap_p4d_range mm/memory.c:2072 [inline] unmap_page_range+0x3c1d/0x48f0 mm/memory.c:2093 unmap_single_vma mm/memory.c:2135 [inline] unmap_vmas+0x48f/0x6a0 mm/memory.c:2173 exit_mmap+0x283/0xa00 mm/mmap.c:1302 __mmput+0x118/0x430 kernel/fork.c:1174 exit_mm+0x168/0x220 kernel/exit.c:581 do_exit+0x62e/0x2310 kernel/exit.c:959 do_group_exit+0x21b/0x2d0 kernel/exit.c:1112 get_signal+0x1284/0x1330 kernel/signal.c:3034 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f353899aeb9 Code: Unable to access opcode bytes at 0x7f353899ae8f. RSP: 002b:00007f3536bf6028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 0000000000000070 RBX: 00007f3538c16090 RCX: 00007f353899aeb9 RDX: 0000000000000040 RSI: 0000200000009b40 RDI: 0000000000000003 RBP: 00007f3538a08c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3538c16128 R14: 00007f3538c16090 R15: 00007fffe1d9e458 ---------------- Code disassembly (best guess): 0: 4d 89 c1 mov %r8,%r9 3: 49 c1 e9 03 shr $0x3,%r9 7: 48 bb 01 00 00 00 00 movabs $0xdffffc0000000001,%rbx e: fc ff df 11: 4d 8d 34 19 lea (%r9,%rbx,1),%r14 15: 4d 89 f4 mov %r14,%r12 18: 4d 29 dc sub %r11,%r12 1b: 49 83 fc 10 cmp $0x10,%r12 1f: 7f 29 jg 0x4a 21: 4d 85 e4 test %r12,%r12 24: 0f 84 3d 01 00 00 je 0x167 * 2a: 4c 89 cb mov %r9,%rbx <-- trapping instruction 2d: 48 f7 d3 not %rbx 30: 4c 01 fb add %r15,%rbx 33: 41 80 3b 00 cmpb $0x0,(%r11) 37: 0f 85 9e 01 00 00 jne 0x1db 3d: 49 ff c3 inc %r11