INFO: task syz.0.15:6895 blocked for more than 143 seconds. Not tainted 6.16.0-rc6-next-20250717-syzkaller-g024e09e444bd #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.15 state:D stack:26168 pid:6895 tgid:6884 ppid:6615 task_flags:0x440140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5314 [inline] __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6697 __schedule_loop kernel/sched/core.c:6775 [inline] schedule+0x165/0x360 kernel/sched/core.c:6790 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:1019 freeze_super+0x905/0x1130 fs/super.c:2197 fs_bdev_freeze+0x1a3/0x310 fs/super.c:1540 bdev_freeze+0xd5/0x220 block/bdev.c:298 xfs_fs_goingdown+0xc5/0x150 fs/xfs/xfs_fsops.c:465 xfs_file_ioctl+0x113e/0x1870 fs/xfs/xfs_ioctl.c:1378 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc6caf80809 RSP: 002b:00007fc6cbdac058 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fc6cb146080 RCX: 00007fc6caf80809 RDX: 0000000020000080 RSI: 000000008004587d RDI: 0000000000000004 RBP: 00007fc6caff393e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fc6cb146080 R15: 00007ffe2be431c8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13e2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13e2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13e2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 5 locks held by kworker/u8:7/1156: #0: ffff88801b2fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #0: ffff88801b2fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322 #1: ffffc90003d6fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline] #1: ffffc90003d6fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322 #2: ffffffff8f51d810 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:658 #3: ffffffff8f52a608 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:172 [inline] #3: ffffffff8f52a608 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990 net/core/net_namespace.c:247 #4: ffffffff8e143e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #4: ffffffff8e143e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:967 2 locks held by getty/5605: #0: ffff88814cd410a0 (&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.0.15/6895: #0: ffff888148d03b30 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289 #1: ffff888021f20428 (sb_writers#12){++++}-{0:0}, at: sb_wait_write fs/super.c:1911 [inline] #1: ffff888021f20428 (sb_writers#12){++++}-{0:0}, at: freeze_super+0x4db/0x1130 fs/super.c:2175 #2: ffff888021f200e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #2: ffff888021f200e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #2: ffff888021f200e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: freeze_super+0x4e3/0x1130 fs/super.c:2176 #3: ffff888021f20520 (sb_pagefaults#2){+.+.}-{0:0}, at: sb_wait_write fs/super.c:1911 [inline] #3: ffff888021f20520 (sb_pagefaults#2){+.+.}-{0:0}, at: freeze_super+0x50a/0x1130 fs/super.c:2180 #4: ffff888021f20618 (sb_internal#2){++++}-{0:0}, at: sb_wait_write fs/super.c:1911 [inline] #4: ffff888021f20618 (sb_internal#2){++++}-{0:0}, at: freeze_super+0x8b7/0x1130 fs/super.c:2194 3 locks held by kworker/0:7/7030: #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322 #1: ffffc90004677bc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline] #1: ffffc90004677bc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322 #2: ffffffff8f52a608 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 3 locks held by kworker/u8:9/7456: #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322 #1: ffffc9000afe7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline] #1: ffffc9000afe7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322 #2: ffffffff8f52a608 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 5 locks held by syz.1.44/7615: #0: ffff888148d046b0 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289 #1: ffff8880335ea428 (sb_writers#12){++++}-{0:0}, at: sb_wait_write fs/super.c:1911 [inline] #1: ffff8880335ea428 (sb_writers#12){++++}-{0:0}, at: freeze_super+0x4db/0x1130 fs/super.c:2175 #2: ffff8880335ea0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #2: ffff8880335ea0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #2: ffff8880335ea0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: freeze_super+0x4e3/0x1130 fs/super.c:2176 #3: ffff8880335ea520 (sb_pagefaults#2){+.+.}-{0:0}, at: sb_wait_write fs/super.c:1911 [inline] #3: ffff8880335ea520 (sb_pagefaults#2){+.+.}-{0:0}, at: freeze_super+0x50a/0x1130 fs/super.c:2180 #4: ffff8880335ea618 (sb_internal#2){++++}-{0:0}, at: sb_wait_write fs/super.c:1911 [inline] #4: ffff8880335ea618 (sb_internal#2){++++}-{0:0}, at: freeze_super+0x8b7/0x1130 fs/super.c:2194 5 locks held by syz.3.39/7660: #0: ffff888148d05db0 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289 #1: ffff888058f8c428 (sb_writers#12){++++}-{0:0}, at: sb_wait_write fs/super.c:1911 [inline] #1: ffff888058f8c428 (sb_writers#12){++++}-{0:0}, at: freeze_super+0x4db/0x1130 fs/super.c:2175 #2: ffff888058f8c0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #2: ffff888058f8c0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #2: ffff888058f8c0e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: freeze_super+0x4e3/0x1130 fs/super.c:2176 #3: ffff888058f8c520 (sb_pagefaults#2){+.+.}-{0:0}, at: sb_wait_write fs/super.c:1911 [inline] #3: ffff888058f8c520 (sb_pagefaults#2){+.+.}-{0:0}, at: freeze_super+0x50a/0x1130 fs/super.c:2180 #4: ffff888058f8c618 (sb_internal#2){++++}-{0:0}, at: sb_wait_write fs/super.c:1911 [inline] #4: ffff888058f8c618 (sb_internal#2){++++}-{0:0}, at: freeze_super+0x8b7/0x1130 fs/super.c:2194 5 locks held by syz.5.50/7863: #0: ffff888148d074b0 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289 #1: ffff88802f356428 (sb_writers#12){++++}-{0:0}, at: sb_wait_write fs/super.c:1911 [inline] #1: ffff88802f356428 (sb_writers#12){++++}-{0:0}, at: freeze_super+0x4db/0x1130 fs/super.c:2175 #2: ffff88802f3560e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #2: ffff88802f3560e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #2: ffff88802f3560e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: freeze_super+0x4e3/0x1130 fs/super.c:2176 #3: ffff88802f356520 (sb_pagefaults#2){+.+.}-{0:0}, at: sb_wait_write fs/super.c:1911 [inline] #3: ffff88802f356520 (sb_pagefaults#2){+.+.}-{0:0}, at: freeze_super+0x50a/0x1130 fs/super.c:2180 #4: ffff88802f356618 (sb_internal#2){++++}-{0:0}, at: sb_wait_write fs/super.c:1911 [inline] #4: ffff88802f356618 (sb_internal#2){++++}-{0:0}, at: freeze_super+0x8b7/0x1130 fs/super.c:2194 1 lock held by syz-executor/9125: #0: ffffffff8f52a608 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f52a608 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f52a608 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 3 locks held by syz.1.220/9133: #0: ffff8880252a0400 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_set_status+0x2c/0xb40 drivers/block/loop.c:1222 #1: ffff888142f4a7e8 (&q->q_usage_counter(io)#18){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline] #1: ffff888142f4a7e8 (&q->q_usage_counter(io)#18){++++}-{0:0}, at: loop_set_status+0x251/0xb40 drivers/block/loop.c:1238 #2: ffff888142f4a820 (&q->q_usage_counter(queue)#22){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline] #2: ffff888142f4a820 (&q->q_usage_counter(queue)#22){+.+.}-{0:0}, at: loop_set_status+0x251/0xb40 drivers/block/loop.c:1238 3 locks held by syz.3.221/9139: #0: ffff8880252a6400 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_set_status+0x2c/0xb40 drivers/block/loop.c:1222 #1: ffff888142f4bb88 (&q->q_usage_counter(io)#20){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline] #1: ffff888142f4bb88 (&q->q_usage_counter(io)#20){++++}-{0:0}, at: loop_set_status+0x251/0xb40 drivers/block/loop.c:1238 #2: ffff888142f4bbc0 (&q->q_usage_counter(queue)#20){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline] #2: ffff888142f4bbc0 (&q->q_usage_counter(queue)#20){+.+.}-{0:0}, at: loop_set_status+0x251/0xb40 drivers/block/loop.c:1238 3 locks held by syz.5.222/9144: #0: ffff888142f74400 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_set_status+0x2c/0xb40 drivers/block/loop.c:1222 #1: ffff888142f4cf28 (&q->q_usage_counter(io)#22){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline] #1: ffff888142f4cf28 (&q->q_usage_counter(io)#22){++++}-{0:0}, at: loop_set_status+0x251/0xb40 drivers/block/loop.c:1238 #2: ffff888142f4cf60 (&q->q_usage_counter(queue)#24){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline] #2: ffff888142f4cf60 (&q->q_usage_counter(queue)#24){+.+.}-{0:0}, at: loop_set_status+0x251/0xb40 drivers/block/loop.c:1238 3 locks held by syz.0.223/9149: #0: ffff888142f5d400 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_set_status+0x2c/0xb40 drivers/block/loop.c:1222 #1: ffff888142f49e18 (&q->q_usage_counter(io)#17){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline] #1: ffff888142f49e18 (&q->q_usage_counter(io)#17){++++}-{0:0}, at: loop_set_status+0x251/0xb40 drivers/block/loop.c:1238 #2: ffff888142f49e50 (&q->q_usage_counter(queue)#23){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline] #2: ffff888142f49e50 (&q->q_usage_counter(queue)#23){+.+.}-{0:0}, at: loop_set_status+0x251/0xb40 drivers/block/loop.c:1238 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-next-20250717-syzkaller-g024e09e444bd #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:328 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 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: 1148 Comm: kworker/u8:6 Not tainted 6.16.0-rc6-next-20250717-syzkaller-g024e09e444bd #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:__lock_acquire+0x28d/0xd20 kernel/locking/lockdep.c:5173 Code: 0a 00 00 41 83 fd 31 48 89 74 24 20 0f 83 5e 0a 00 00 4c 89 6c 24 28 4a 8d 04 ad 00 00 00 00 4c 01 e8 89 f1 81 e1 ff 1f 00 00 00 e0 ff ff 41 23 54 c7 20 09 ca 41 89 54 c7 20 4d 89 4c c7 08 RSP: 0018:ffffc90003baf8f0 EFLAGS: 00000002 RAX: 000000000000000a RBX: ffffffff8e13e2e0 RCX: 0000000000000007 RDX: 0000000000000002 RSI: 0000000000000007 RDI: ffff88802700bc00 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8b474662 R10: dffffc0000000000 R11: ffffffff8b474590 R12: 0000000000000002 R13: 0000000000000002 R14: 0000000000000000 R15: ffff88802700c6f0 FS: 0000000000000000(0000) GS:ffff888125bd9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffdb5ddfba8 CR3: 000000007e782000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3239 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3322 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3403 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245