INFO: task kworker/u8:6:3547 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:6 state:D stack:25400 pid:3547 tgid:3547 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events_unbound netfs_write_collection_worker Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 netfs_wait_for_in_progress_stream+0x17a/0x440 fs/netfs/misc.c:370 netfs_retry_writes+0x1394/0x19c0 fs/netfs/write_retry.c:214 netfs_collect_write_results fs/netfs/write_collect.c:349 [inline] netfs_write_collection+0x19ee/0x36d0 fs/netfs/write_collect.c:365 netfs_write_collection_worker+0xea/0x1d0 fs/netfs/write_collect.c:448 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 2 locks held by kworker/u8:0/12: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90000117d10 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 2 locks held by kworker/u8:1/13: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90000127d10 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 1 lock held by khungtaskd/31: #0: ffffffff8e5c1220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c1220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c1220 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:2/36: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90000ac7d10 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 2 locks held by kworker/u8:3/37: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90000ad7d10 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 2 locks held by kworker/u8:4/64: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000212fd10 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 2 locks held by kworker/u8:5/1001: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90003b0fd10 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 2 locks held by kworker/u8:6/3547: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000cd37d10 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 2 locks held by kworker/u8:7/3561: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000ccb7d10 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 2 locks held by kworker/u8:8/3588: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000ce07d10 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 2 locks held by getty/5605: #0: ffff8880327ef0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by syz.0.17/6047: #0: ffff88805fb50500 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xba/0x920 fs/netfs/write_issue.c:559 1 lock held by syz.1.18/6068: #0: ffff88805fb50b70 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xba/0x920 fs/netfs/write_issue.c:559 1 lock held by syz.2.20/6097: #0: ffff88805b4e0500 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xba/0x920 fs/netfs/write_issue.c:559 1 lock held by syz.3.22/6123: #0: ffff88805fb51ec0 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xba/0x920 fs/netfs/write_issue.c:559 1 lock held by syz.4.23/6151: #0: ffff88805fb52530 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xba/0x920 fs/netfs/write_issue.c:559 2 locks held by kworker/u8:10/6170: #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90003217d10 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 1 lock held by syz.5.24/6181: #0: ffff88805fb51850 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xba/0x920 fs/netfs/write_issue.c:559 1 lock held by syz.6.25/6214: #0: ffff88805fb52ba0 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xba/0x920 fs/netfs/write_issue.c:559 1 lock held by syz.7.26/6244: #0: ffff88805b4e0b70 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xba/0x920 fs/netfs/write_issue.c:559 1 lock held by syz.8.29/6276: #0: ffff88805b4e11e0 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xba/0x920 fs/netfs/write_issue.c:559 2 locks held by kworker/u8:14/6298: #0: ffff8880b853a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:636 #1: ffffc90002df7d10 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 1 lock held by syz.9.30/6308: #0: ffff88805b4e1850 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xba/0x920 fs/netfs/write_issue.c:559 ============================================= 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 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/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+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 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: 6298 Comm: kworker/u8:14 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:hlock_class+0x4/0x70 kernel/locking/lockdep.c:229 Code: 0f 0b 90 e9 01 ff ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f b7 47 20 <66> 25 ff 1f 0f b7 c0 48 0f a3 05 4d c1 45 14 73 15 48 8d 04 80 48 RSP: 0018:ffffc90002df79d8 EFLAGS: 00000002 RAX: 0000000000000007 RBX: ffff8880793a8af0 RCX: 0000000000020000 RDX: 0000000000000007 RSI: 0000000000000000 RDI: ffff8880793a8b40 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000050 R11: 0000000000000001 R12: ffff8880793a8b40 R13: ffff8880793a8000 R14: 0000000000000000 R15: ffffffff8e5c1220 FS: 0000000000000000(0000) GS:ffff8881247bb000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555865f5dbe0 CR3: 000000000e380000 CR4: 00000000003526f0 Call Trace: check_wait_context kernel/locking/lockdep.c:4854 [inline] __lock_acquire+0x218/0x1ce0 kernel/locking/lockdep.c:5187 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 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+0x16a/0x1030 net/batman-adv/network-coding.c:719 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245