INFO: task kworker/u4:7:3700 blocked for more than 143 seconds. Not tainted 5.15.164-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:7 state:D stack:22752 pid: 3700 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:1) Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 jfs_commit_inode+0x242/0x580 fs/jfs/inode.c:102 jfs_write_inode+0x13f/0x210 fs/jfs/inode.c:132 write_inode fs/fs-writeback.c:1495 [inline] __writeback_single_inode+0x644/0xe30 fs/fs-writeback.c:1705 writeback_sb_inodes+0xbce/0x1a40 fs/fs-writeback.c:1930 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:2001 wb_writeback+0x465/0xc50 fs/fs-writeback.c:2106 wb_check_background_flush fs/fs-writeback.c:2172 [inline] wb_do_writeback fs/fs-writeback.c:2260 [inline] wb_workfn+0xd07/0x1130 fs/fs-writeback.c:2288 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 INFO: task syz.1.168:4612 blocked for more than 143 seconds. Not tainted 5.15.164-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.168 state:D stack:25624 pid: 4612 ppid: 4337 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 rwsem_down_read_slowpath+0x605/0xb40 kernel/locking/rwsem.c:1055 __down_read_common kernel/locking/rwsem.c:1239 [inline] __down_read kernel/locking/rwsem.c:1252 [inline] down_read+0x9a/0x2e0 kernel/locking/rwsem.c:1500 inode_lock_shared include/linux/fs.h:799 [inline] lookup_slow+0x45/0x70 fs/namei.c:1679 walk_component+0x48c/0x610 fs/namei.c:1976 link_path_walk+0x642/0xd90 path_parentat fs/namei.c:2502 [inline] __filename_parentat+0x24c/0x6c0 fs/namei.c:2526 filename_parentat fs/namei.c:2544 [inline] filename_create+0xf2/0x530 fs/namei.c:3816 do_mkdirat+0xb3/0x520 fs/namei.c:4080 __do_sys_mkdirat fs/namei.c:4105 [inline] __se_sys_mkdirat fs/namei.c:4103 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4103 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f4d49e1d9f9 RSP: 002b:00007f4d4825a048 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f4d49fac130 RCX: 00007f4d49e1d9f9 RDX: 00000000000001ff RSI: 0000000020000000 RDI: ffffffffffffff9c RBP: 00007f4d49e8b8ee R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f4d49fac130 R15: 00007ffed9037b08 INFO: task syz.1.168:4613 blocked for more than 144 seconds. Not tainted 5.15.164-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.168 state:D stack:26712 pid: 4613 ppid: 4337 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 rwsem_down_read_slowpath+0x605/0xb40 kernel/locking/rwsem.c:1055 __down_read_common kernel/locking/rwsem.c:1239 [inline] __down_read kernel/locking/rwsem.c:1252 [inline] down_read+0x9a/0x2e0 kernel/locking/rwsem.c:1500 inode_lock_shared include/linux/fs.h:799 [inline] lookup_slow+0x45/0x70 fs/namei.c:1679 walk_component+0x48c/0x610 fs/namei.c:1976 link_path_walk+0x642/0xd90 path_lookupat+0xa9/0x450 fs/namei.c:2454 do_o_path+0x91/0x230 fs/namei.c:3713 path_openat+0x2944/0x2f20 fs/namei.c:3735 do_filp_open+0x21c/0x460 fs/namei.c:3769 do_sys_openat2+0x13b/0x4f0 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1280 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f4d49e1d9f9 RSP: 002b:00007f4d48037048 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f4d49fac208 RCX: 00007f4d49e1d9f9 RDX: 0000000000200002 RSI: 0000000020000240 RDI: ffffffffffffff9c RBP: 00007f4d49e8b8ee R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f4d49fac208 R15: 00007ffed9037b08 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by kworker/u4:5/2663: 2 locks held by getty/3325: #0: ffff88814b097098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002bab2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 1 lock held by syz-executor/3557: #0: ffff8880b9a3a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa8/0x140 kernel/sched/core.c:483 2 locks held by kworker/0:8/3645: #0: ffff888011c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900030d7d20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 4 locks held by kworker/u4:7/3700: #0: ffff8880165f5138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90002df7d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff88805bf3c0e0 (&type->s_umount_key#65){++++}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418 #3: ffff888074096788 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x242/0x580 fs/jfs/inode.c:102 4 locks held by syz.1.168/4607: 1 lock held by syz.1.168/4612: #0: ffff888074096b40 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:799 [inline] #0: ffff888074096b40 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: lookup_slow+0x45/0x70 fs/namei.c:1679 1 lock held by syz.1.168/4613: #0: ffff888074096b40 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:799 [inline] #0: ffff888074096b40 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: lookup_slow+0x45/0x70 fs/namei.c:1679 3 locks held by kworker/1:11/4744: #0: ffff888011c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90002c47d20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8c9240e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #2: ffffffff8c9240e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x350/0x740 kernel/rcu/tree_exp.h:845 3 locks held by kworker/0:21/5163: #0: ffff888011c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900032b7d20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8c9240e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #2: ffffffff8c9240e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845 1 lock held by syz-executor/5832: #0: ffff88807e2c20e0 (&type->s_umount_key#58){+.+.}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365 1 lock held by syz.2.538/6950: #0: ffffffff8c923ff0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x9c/0x4e0 kernel/rcu/tree.c:4039 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.164-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:295 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:108 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:562