INFO: task kworker/u4:12:23918 blocked for more than 143 seconds. Not tainted 6.5.0-rc1-syzkaller-00259-g831fe284d827 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:12 state:D stack:20696 pid:23918 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:2) Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1873/0x48f0 kernel/sched/core.c:6710 schedule+0xc3/0x180 kernel/sched/core.c:6786 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6845 __mutex_lock_common+0xe33/0x2530 kernel/locking/mutex.c:679 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799 jfs_commit_inode+0x246/0x580 fs/jfs/inode.c:102 jfs_write_inode+0x143/0x210 fs/jfs/inode.c:132 write_inode fs/fs-writeback.c:1456 [inline] __writeback_single_inode+0x69b/0xfa0 fs/fs-writeback.c:1668 writeback_sb_inodes+0x8e3/0x11d0 fs/fs-writeback.c:1894 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:1965 wb_writeback+0x461/0xc60 fs/fs-writeback.c:2072 wb_check_old_data_flush fs/fs-writeback.c:2176 [inline] wb_do_writeback fs/fs-writeback.c:2229 [inline] wb_workfn+0xbb5/0xff0 fs/fs-writeback.c:2257 process_one_work+0x92c/0x12c0 kernel/workqueue.c:2597 worker_thread+0xa63/0x1210 kernel/workqueue.c:2748 kthread+0x2b8/0x350 kernel/kthread.c:389 ret_from_fork+0x2e/0x60 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:296 RIP: 0000:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 0000:0000000000000000 EFLAGS: 00000000 ORIG_RAX: 0000000000000000 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8d328af0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:522 1 lock held by rcu_tasks_trace/14: #0: ffffffff8d328eb0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:522 1 lock held by khungtaskd/28: #0: ffffffff8d328920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/4766: #0: ffff88814b11e098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900015a02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b1/0x1dc0 drivers/tty/n_tty.c:2187 3 locks held by syz-executor.1/5046: 1 lock held by syz-executor.5/5053: #0: ffffffff8d32dfb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:293 [inline] #0: ffffffff8d32dfb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a3/0x890 kernel/rcu/tree_exp.h:992 4 locks held by kworker/u4:12/23918: #0: ffff88814525e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7e3/0x12c0 kernel/workqueue.c:2569 #1: ffffc9000420fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x82b/0x12c0 kernel/workqueue.c:2571 #2: ffff88804b33e0e0 (&type->s_umount_key#85){++++}-{3:3}, at: trylock_super+0x1f/0xf0 fs/super.c:413 #3: ffff888081780b08 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x246/0x580 fs/jfs/inode.c:102 4 locks held by kworker/u4:13/23919: #0: ffff88814525e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7e3/0x12c0 kernel/workqueue.c:2569 #1: ffffc9000421fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x82b/0x12c0 kernel/workqueue.c:2571 #2: ffff8880903dc0e0 (&type->s_umount_key#85){++++}-{3:3}, at: trylock_super+0x1f/0xf0 fs/super.c:413 #3: ffff8880441ccbc8 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x246/0x580 fs/jfs/inode.c:102 3 locks held by kworker/u4:16/23922: 2 locks held by kworker/1:10/29228: #0: ffff888012872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7e3/0x12c0 kernel/workqueue.c:2569 #1: ffffc9000bf2fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x82b/0x12c0 kernel/workqueue.c:2571 4 locks held by syz-executor.2/3869: 4 locks held by syz-executor.3/4048: 2 locks held by syz-executor.0/4399: 2 locks held by syz-executor.4/4401: 2 locks held by syz-executor.1/4403: 1 lock held by syz-executor.3/4407: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.5.0-rc1-syzkaller-00259-g831fe284d827 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x498/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x187/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xec2/0xf00 kernel/hung_task.c:379 kthread+0x2b8/0x350 kernel/kthread.c:389 ret_from_fork+0x2e/0x60 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:296 RIP: 0000:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 0000:0000000000000000 EFLAGS: 00000000 ORIG_RAX: 0000000000000000 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4405 Comm: syz-executor.2 Not tainted 6.5.0-rc1-syzkaller-00259-g831fe284d827 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023 RIP: 0033:0x7f52d9c28728 Code: 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 47 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b 47 10 <48> 83 c0 01 49 89 47 10 83 e9 01 73 d3 41 81 fe 00 01 00 00 0f 85 RSP: 002b:00007f52daaba520 EFLAGS: 00000246 RAX: 000000000087b480 RBX: 00007f52daaba5c0 RCX: 000000000000005b RDX: 0000000000000005 RSI: 0000000000000001 RDI: 00007f52daaba660 RBP: 0000000000000102 R08: 00007f52d03ff000 R09: 0000000000000000 R10: 0000000000000000 R11: 00007f52daaba5d0 R12: 0000000000000001 R13: 00007f52d9cea340 R14: 0000000000000000 R15: 00007f52daaba660 FS: 00007f52daabb6c0 GS: 0000000000000000