INFO: task kworker/u8:3:44 blocked for more than 143 seconds. Not tainted 6.15.0-syzkaller-13659-g5b032cac6225 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:3 state:D stack:21992 pid:44 tgid:44 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:3) Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747 jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102 jfs_write_inode+0x145/0x220 fs/jfs/inode.c:132 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0x6ee/0xff0 fs/fs-writeback.c:1745 writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047 wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158 wb_check_start_all fs/fs-writeback.c:2284 [inline] wb_do_writeback fs/fs-writeback.c:2310 [inline] wb_workfn+0x90b/0xef0 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.2.57:6426 blocked for more than 144 seconds. Not tainted 6.15.0-syzkaller-13659-g5b032cac6225 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.57 state:D stack:25160 pid:6426 tgid:6425 ppid:5836 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216 sync_inodes_sb+0x1bb/0xa10 fs/fs-writeback.c:2833 __iterate_supers+0x13a/0x250 fs/super.c:924 ksys_sync+0x94/0x150 fs/sync.c:102 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 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: 0033:0x7fdde138e929 RSP: 002b:00007fdde2112038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007fdde15b5fa0 RCX: 00007fdde138e929 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fdde15b5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fdde15b5fa0 R15: 00007ffc452c5518 Showing all locks held in the system: 2 locks held by kworker/u8:0/12: #0: ffff8880b873b798 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606 #1: ffff8880b8723f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987 1 lock held by khungtaskd/31: #0: ffffffff8e13f060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13f060 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 4 locks held by kworker/u8:3/44: #0: ffff8881432d1148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8881432d1148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90000b47bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000b47bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffff888030d8c0e0 (&type->s_umount_key#100){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 #3: ffff888056942fe0 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102 2 locks held by kworker/u8:6/1336: #0: ffff888145294148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888145294148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc9000435fbc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] ffffc9000435fbc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 2 locks held by getty/5587: #0: ffff88814cee50a0 (&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.3.18/6099: 2 locks held by syz.2.57/6426: #0: ffff888030d8c0e0 (&type->s_umount_key#100){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888030d8c0e0 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff8881427c47d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8881427c47d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831 2 locks held by syz.1.151/7163: #0: ffff888030d8c0e0 (&type->s_umount_key#100){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888030d8c0e0 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff8881427c47d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8881427c47d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831 2 locks held by rm/8499: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-syzkaller-13659-g5b032cac6225 #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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x70e/0x8a0 kernel/kthread.c:464 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6099 Comm: syz.3.18 Not tainted 6.15.0-syzkaller-13659-g5b032cac6225 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d 14 d9 f8 0b 48 89 de 5b e9 d3 85 56 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 c0 99 92 65 8b 15 f8 74 d9 10 81 e2 00 01 ff 00 RSP: 0018:ffffc9000eb1f680 EFLAGS: 00000202 RAX: ffffffff833cb2af RBX: 0000000000000004 RCX: 0000000000000002 RDX: ffff8880350f0000 RSI: 0000000000000007 RDI: 00000000000000ff RBP: 0000000000000007 R08: 0000000000000106 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff88805199d000 R14: 0000000000000007 R15: 1ffff1100a333a02 FS: 00007f3482ed26c0(0000) GS:ffff888125d84000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005616ac91fd51 CR3: 00000000248b8000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dtSplitRoot+0x77f/0x16c0 fs/jfs/jfs_dtree.c:1979 dtSplitUp fs/jfs/jfs_dtree.c:993 [inline] dtInsert+0xef8/0x5f40 fs/jfs/jfs_dtree.c:871 jfs_link+0x312/0x550 fs/jfs/namei.c:826 vfs_link+0x4ed/0x6e0 fs/namei.c:4854 do_linkat+0x272/0x560 fs/namei.c:4924 __do_sys_link fs/namei.c:4958 [inline] __se_sys_link fs/namei.c:4956 [inline] __x64_sys_link+0x82/0x90 fs/namei.c:4956 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: 0033:0x7f3481f8e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3482ed2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000056 RAX: ffffffffffffffda RBX: 00007f34821b5fa0 RCX: 00007f3481f8e929 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000200000000940 RBP: 00007f3482010b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f34821b5fa0 R15: 00007ffc7afa8948