INFO: task kworker/u4:2:148 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:2 state:D stack: 0 pid: 148 ppid: 2 flags:0x00000008 Workqueue: writeback wb_workfn (flush-7:0) Call trace: __switch_to+0x2f4/0x558 arch/arm64/kernel/process.c:521 context_switch kernel/sched/core.c:5049 [inline] __schedule+0xe08/0x1bf8 kernel/sched/core.c:6395 schedule+0x11c/0x1c8 kernel/sched/core.c:6478 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6537 __mutex_lock_common+0xa9c/0x1edc kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0xac/0x11c kernel/locking/mutex.c:743 jfs_commit_inode+0x19c/0x498 fs/jfs/inode.c:102 jfs_write_inode+0x128/0x1f8 fs/jfs/inode.c:132 write_inode fs/fs-writeback.c:1495 [inline] __writeback_single_inode+0x560/0x11f0 fs/fs-writeback.c:1705 writeback_sb_inodes+0x7fc/0x1378 fs/fs-writeback.c:1930 __writeback_inodes_wb+0x110/0x394 fs/fs-writeback.c:2001 wb_writeback+0x3ec/0xe44 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+0xa7c/0xdd8 fs/fs-writeback.c:2288 process_one_work+0x79c/0x1140 kernel/workqueue.c:2310 worker_thread+0x8f4/0x101c kernel/workqueue.c:2457 kthread+0x374/0x454 kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:856 Showing all locks held in the system: 4 locks held by kworker/u4:0/9: #0: ffff0000c21e0138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff80001b2f7c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000ce18a0e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000ee45b008 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x19c/0x498 fs/jfs/inode.c:102 1 lock held by khungtaskd/27: #0: ffff8000143513a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:311 4 locks held by kworker/u4:1/136: #0: ffff0000c21e0138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff80001b9a7c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000e819e0e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000ee5a01c8 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x19c/0x498 fs/jfs/inode.c:102 4 locks held by kworker/u4:2/148: #0: ffff0000c21e0138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff80001be87c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000d94160e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000e26e3008 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x19c/0x498 fs/jfs/inode.c:102 4 locks held by kworker/u4:3/294: #0: ffff0000c21e0138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff80001bef7c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000d74a20e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000e26e70c8 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x19c/0x498 fs/jfs/inode.c:102 4 locks held by kworker/u4:4/377: #0: ffff0000c21e0138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff80001f767c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000d2fe20e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000ee45f0c8 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x19c/0x498 fs/jfs/inode.c:102 4 locks held by kworker/u4:5/1644: #0: ffff0000c21e0138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff800023cb7c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000caca40e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000ee4c81c8 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x19c/0x498 fs/jfs/inode.c:102 2 locks held by getty/3805: #0: ffff0000d4ed3098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340 #1: ffff80001bd4e2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x2f0/0xf6c drivers/tty/n_tty.c:2158 3 locks held by kworker/0:6/4166: #0: ffff0000c0020938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff80001fa57c00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000f3111240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x1c8/0x2704 drivers/net/netdevsim/fib.c:1480 4 locks held by syz.0.16/4974: 4 locks held by syz.1.17/5006: 4 locks held by syz.2.18/5027: 4 locks held by kworker/u4:6/5028: #0: ffff0000c21e0138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff80001ffb7c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000d4ee60e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000ee4d3948 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x19c/0x498 fs/jfs/inode.c:102 4 locks held by syz.3.19/5051: 4 locks held by kworker/u4:8/5087: #0: ffff0000c21e0138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff8000200e7c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000f49220e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000ee53b948 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x19c/0x498 fs/jfs/inode.c:102 4 locks held by syz.4.20/5089: 4 locks held by syz.5.21/5121: 4 locks held by syz.6.22/5153: 4 locks held by kworker/u4:11/5154: #0: ffff0000c21e0138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff800020377c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000f3ff20e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000ee4cc288 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x19c/0x498 fs/jfs/inode.c:102 4 locks held by syz.7.23/5191: 4 locks held by syz.8.24/5223: 4 locks held by syz.9.25/5257: =============================================