INFO: task syz.2.17:6491 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.17 state:D stack:26696 pid:6491 tgid:6460 ppid:6306 task_flags:0x440140 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 xfs_ail_push_all_sync+0x1cd/0x2a0 fs/xfs/xfs_trans_ail.c:721 xfs_log_quiesce+0xdf/0x5d0 fs/xfs/xfs_log.c:1019 xfs_fs_freeze+0x7f/0x160 fs/xfs/xfs_super.c:1015 freeze_super+0x905/0x1130 fs/super.c:2133 fs_bdev_freeze+0x1a3/0x310 fs/super.c:1539 bdev_freeze+0xd8/0x220 block/bdev.c:298 xfs_fs_goingdown+0xc5/0x150 fs/xfs/xfs_fsops.c:465 xfs_file_ioctl+0x11b8/0x1830 fs/xfs/xfs_ioctl.c:1371 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f19c9f80809 RSP: 002b:00007f19cad8c058 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f19ca146080 RCX: 00007f19c9f80809 RDX: 0000000020000080 RSI: 000000008004587d RDI: 0000000000000004 RBP: 00007f19c9ff393e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f19ca146080 R15: 00007fffa5cd9758 INFO: task syz.4.19:6508 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.19 state:D stack:26952 pid:6508 tgid:6483 ppid:6311 task_flags:0x440140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 xfs_ail_push_all_sync+0x1cd/0x2a0 fs/xfs/xfs_trans_ail.c:721 xfs_log_quiesce+0xdf/0x5d0 fs/xfs/xfs_log.c:1019 xfs_fs_freeze+0x7f/0x160 fs/xfs/xfs_super.c:1015 freeze_super+0x905/0x1130 fs/super.c:2133 fs_bdev_freeze+0x1a3/0x310 fs/super.c:1539 bdev_freeze+0xd8/0x220 block/bdev.c:298 xfs_fs_goingdown+0xc5/0x150 fs/xfs/xfs_fsops.c:465 xfs_file_ioctl+0x11b8/0x1830 fs/xfs/xfs_ioctl.c:1371 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9c24f80809 RSP: 002b:00007f9c25cbb058 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f9c25146080 RCX: 00007f9c24f80809 RDX: 0000000020000080 RSI: 000000008004587d RDI: 0000000000000004 RBP: 00007f9c24ff393e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f9c25146080 R15: 00007ffe0f3f9f88 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e33d360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33d360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e33d360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5627: #0: ffff88814db830a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222 5 locks held by syz.2.17/6491: #0: ffff888148c701b0 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289 #1: ffff888055302420 (sb_writers#12){++++}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #1: ffff888055302420 (sb_writers#12){++++}-{0:0}, at: freeze_super+0x4db/0x1130 fs/super.c:2111 #2: ffff8880553020e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #2: ffff8880553020e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #2: ffff8880553020e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: freeze_super+0x4e3/0x1130 fs/super.c:2112 #3: ffff888055302518 (sb_pagefaults#2){+.+.}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #3: ffff888055302518 (sb_pagefaults#2){+.+.}-{0:0}, at: freeze_super+0x50a/0x1130 fs/super.c:2116 #4: ffff888055302610 (sb_internal#2){++++}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #4: ffff888055302610 (sb_internal#2){++++}-{0:0}, at: freeze_super+0x8b7/0x1130 fs/super.c:2130 5 locks held by syz.4.19/6508: #0: ffff888148c718b0 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289 #1: ffff88803232e420 (sb_writers#12){++++}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #1: ffff88803232e420 (sb_writers#12){++++}-{0:0}, at: freeze_super+0x4db/0x1130 fs/super.c:2111 #2: ffff88803232e0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #2: ffff88803232e0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #2: ffff88803232e0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: freeze_super+0x4e3/0x1130 fs/super.c:2112 #3: ffff88803232e518 (sb_pagefaults#2){+.+.}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #3: ffff88803232e518 (sb_pagefaults#2){+.+.}-{0:0}, at: freeze_super+0x50a/0x1130 fs/super.c:2116 #4: ffff88803232e610 (sb_internal#2){++++}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #4: ffff88803232e610 (sb_internal#2){++++}-{0:0}, at: freeze_super+0x8b7/0x1130 fs/super.c:2130 5 locks held by syz.7.28/6877: #0: ffff888148c73b30 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289 #1: ffff88802a018420 (sb_writers#12){++++}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #1: ffff88802a018420 (sb_writers#12){++++}-{0:0}, at: freeze_super+0x4db/0x1130 fs/super.c:2111 #2: ffff88802a0180e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #2: ffff88802a0180e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #2: ffff88802a0180e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: freeze_super+0x4e3/0x1130 fs/super.c:2112 #3: ffff88802a018518 (sb_pagefaults#2){+.+.}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #3: ffff88802a018518 (sb_pagefaults#2){+.+.}-{0:0}, at: freeze_super+0x50a/0x1130 fs/super.c:2116 #4: ffff88802a018610 (sb_internal#2){++++}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #4: ffff88802a018610 (sb_internal#2){++++}-{0:0}, at: freeze_super+0x8b7/0x1130 fs/super.c:2130 5 locks held by syz.5.48/7507: #0: ffff888148c72430 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289 #1: ffff888074d40420 (sb_writers#12){++++}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #1: ffff888074d40420 (sb_writers#12){++++}-{0:0}, at: freeze_super+0x4db/0x1130 fs/super.c:2111 #2: ffff888074d400e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #2: ffff888074d400e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #2: ffff888074d400e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: freeze_super+0x4e3/0x1130 fs/super.c:2112 #3: ffff888074d40518 (sb_pagefaults#2){+.+.}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #3: ffff888074d40518 (sb_pagefaults#2){+.+.}-{0:0}, at: freeze_super+0x50a/0x1130 fs/super.c:2116 #4: ffff888074d40610 (sb_internal#2){++++}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #4: ffff888074d40610 (sb_internal#2){++++}-{0:0}, at: freeze_super+0x8b7/0x1130 fs/super.c:2130 5 locks held by syz.9.92/7997: #0: ffff888148c75230 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289 #1: ffff88805d34e420 (sb_writers#12){++++}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #1: ffff88805d34e420 (sb_writers#12){++++}-{0:0}, at: freeze_super+0x4db/0x1130 fs/super.c:2111 #2: ffff88805d34e0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #2: ffff88805d34e0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #2: ffff88805d34e0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: freeze_super+0x4e3/0x1130 fs/super.c:2112 #3: ffff88805d34e518 (sb_pagefaults#2){+.+.}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #3: ffff88805d34e518 (sb_pagefaults#2){+.+.}-{0:0}, at: freeze_super+0x50a/0x1130 fs/super.c:2116 #4: ffff88805d34e610 (sb_internal#2){++++}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #4: ffff88805d34e610 (sb_internal#2){++++}-{0:0}, at: freeze_super+0x8b7/0x1130 fs/super.c:2130 5 locks held by syz.8.183/8617: #0: ffff888148c746b0 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289 #1: ffff888049d32420 (sb_writers#12){++++}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #1: ffff888049d32420 (sb_writers#12){++++}-{0:0}, at: freeze_super+0x4db/0x1130 fs/super.c:2111 #2: ffff888049d320e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #2: ffff888049d320e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #2: ffff888049d320e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: freeze_super+0x4e3/0x1130 fs/super.c:2112 #3: ffff888049d32518 (sb_pagefaults#2){+.+.}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #3: ffff888049d32518 (sb_pagefaults#2){+.+.}-{0:0}, at: freeze_super+0x50a/0x1130 fs/super.c:2116 #4: ffff888049d32610 (sb_internal#2){++++}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #4: ffff888049d32610 (sb_internal#2){++++}-{0:0}, at: freeze_super+0x8b7/0x1130 fs/super.c:2130 1 lock held by syz-executor/8841: #0: ffffffff8e342df8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e342df8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 5 locks held by syz.1.264/9040: #0: ffff888148c474b0 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289 #1: ffff888029332420 (sb_writers#12){++++}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #1: ffff888029332420 (sb_writers#12){++++}-{0:0}, at: freeze_super+0x4db/0x1130 fs/super.c:2111 #2: ffff8880293320e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #2: ffff8880293320e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #2: ffff8880293320e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: freeze_super+0x4e3/0x1130 fs/super.c:2112 #3: ffff888029332518 (sb_pagefaults#2){+.+.}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #3: ffff888029332518 (sb_pagefaults#2){+.+.}-{0:0}, at: freeze_super+0x50a/0x1130 fs/super.c:2116 #4: ffff888029332610 (sb_internal#2){++++}-{0:0}, at: sb_wait_write fs/super.c:1847 [inline] #4: ffff888029332610 (sb_internal#2){++++}-{0:0}, at: freeze_super+0x8b7/0x1130 fs/super.c:2130 1 lock held by syz.4.321/9135: 3 locks held by syz.7.319/9137: #0: ffff888142775440 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_set_status+0xa2/0xd60 drivers/block/loop.c:1232 #1: ffff888142769448 (&q->q_usage_counter(io)#24){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:938 [inline] #1: ffff888142769448 (&q->q_usage_counter(io)#24){++++}-{0:0}, at: loop_set_status+0x2e4/0xd60 drivers/block/loop.c:1248 #2: ffff888142769480 (&q->q_usage_counter(queue)#8){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:938 [inline] #2: ffff888142769480 (&q->q_usage_counter(queue)#8){+.+.}-{0:0}, at: loop_set_status+0x2e4/0xd60 drivers/block/loop.c:1248 3 locks held by syz.2.320/9140: #0: ffff888025376440 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_set_status+0xa2/0xd60 drivers/block/loop.c:1232 #1: ffff888141fc62c8 (&q->q_usage_counter(io)#19){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:938 [inline] #1: ffff888141fc62c8 (&q->q_usage_counter(io)#19){++++}-{0:0}, at: loop_set_status+0x2e4/0xd60 drivers/block/loop.c:1248 #2: ffff888141fc6300 (&q->q_usage_counter(queue)#3){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:938 [inline] #2: ffff888141fc6300 (&q->q_usage_counter(queue)#3){+.+.}-{0:0}, at: loop_set_status+0x2e4/0xd60 drivers/block/loop.c:1248 4 locks held by dhcpcd-run-hook/9154: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 60 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x3a/0xb0 kernel/rcu/tree.c:751 Code: e8 8b 73 d7 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd d0 4d dc 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 8c 9f 7e 00 48 c7 c3 d8 ff c2 92 49 03 1e 48 89 RSP: 0018:ffffc90000007278 EFLAGS: 00000246 RAX: 1ffffffff1bb89ba RBX: 0000000000000000 RCX: 7d61e902db56a500 RDX: 0000000000000000 RSI: ffffffff8c03d4c0 RDI: ffffffff8c03d480 RBP: ffffffff81742d25 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90000007458 R11: ffffffff81acd5c0 R12: 0000000000000002 R13: ffffffff8e33d360 R14: ffffffff8ddc4dd0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125a03000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd193a8d068 CR3: 000000007cf92000 CR4: 00000000003526f0 Call Trace: trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x5f/0x360 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 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 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2507 [inline] slab_free mm/slub.c:6557 [inline] kmem_cache_free+0x19b/0x690 mm/slub.c:6668 kfree_skb_reason include/linux/skbuff.h:1322 [inline] __netif_receive_skb_core+0x3a01/0x4020 net/core/dev.c:6052 __netif_receive_skb_one_core net/core/dev.c:6076 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6191 process_backlog+0x60e/0x14f0 net/core/dev.c:6543 __napi_poll+0xc7/0x360 net/core/dev.c:7593 napi_poll net/core/dev.c:7656 [inline] net_rx_action+0x707/0xe30 net/core/dev.c:7783 handle_softirqs+0x286/0x870 kernel/softirq.c:622 do_softirq+0xec/0x180 kernel/softirq.c:523 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:936 [inline] __dev_queue_xmit+0x1d79/0x3b50 net/core/dev.c:4790 dev_queue_xmit include/linux/netdevice.h:3368 [inline] batadv_send_skb_packet+0x418/0x690 net/batman-adv/send.c:100 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:391 [inline] batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:419 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x62f/0x7e0 net/batman-adv/bat_iv_ogm.c:1697 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245