INFO: task kworker/u4:4:439 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:4 state:D stack: 0 pid: 439 ppid: 2 flags:0x00000008 Workqueue: writeback wb_workfn (flush-7:0) Call trace: __switch_to+0x2f4/0x540 arch/arm64/kernel/process.c:521 context_switch kernel/sched/core.c:5049 [inline] __schedule+0xdfc/0x1bc4 kernel/sched/core.c:6395 schedule+0x11c/0x1c8 kernel/sched/core.c:6478 rwsem_down_write_slowpath+0xc34/0x145c kernel/locking/rwsem.c:1165 __down_write_common kernel/locking/rwsem.c:1292 [inline] __down_write kernel/locking/rwsem.c:1301 [inline] down_write+0xe8/0x12c kernel/locking/rwsem.c:1552 f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 f2fs_write_inode+0x3f4/0x598 fs/f2fs/inode.c:745 write_inode fs/fs-writeback.c:1505 [inline] __writeback_single_inode+0x560/0x11c8 fs/fs-writeback.c:1715 writeback_sb_inodes+0x830/0x13a8 fs/fs-writeback.c:1940 __writeback_inodes_wb+0x110/0x394 fs/fs-writeback.c:2011 wb_writeback+0x400/0xe64 fs/fs-writeback.c:2116 wb_check_background_flush fs/fs-writeback.c:2182 [inline] wb_do_writeback fs/fs-writeback.c:2270 [inline] wb_workfn+0xae8/0xe44 fs/fs-writeback.c:2298 process_one_work+0x79c/0x1138 kernel/workqueue.c:2310 worker_thread+0x8f4/0x1034 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: 3 locks held by kworker/0:0/7: #0: ffff0000c0020938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff80001b3e7c00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0001114cb240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x1dc/0x27f0 drivers/net/netdevsim/fib.c:1480 4 locks held by kworker/u4:0/9: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff80001b407c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0001063580e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0001044b11b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 1 lock held by khungtaskd/27: #0: ffff800014461360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:312 4 locks held by kworker/u4:1/136: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff80001baa7c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0000d97ca0e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000d95b11b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 4 locks held by kworker/u4:2/148: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff80001bf57c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0000d326a0e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000d26791b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 4 locks held by kworker/u4:3/343: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff80001f617c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0000db2580e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000fbc291b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 4 locks held by kworker/u4:4/439: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff80001f7b7c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0000ddd5c0e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000c2bc11b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 4 locks held by kworker/u4:5/1644: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff800023c87c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0000d2dca0e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000d67cd1b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 2 locks held by getty/3804: #0: ffff0000d4f40098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340 #1: ffff80001b9032e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x2f0/0xf6c drivers/tty/n_tty.c:2158 4 locks held by syz.0.16/4966: 5 locks held by syz.1.17/4995: 2 locks held by kworker/u4:6/5016: 5 locks held by syz.2.18/5022: 6 locks held by syz.3.19/5047: 4 locks held by kworker/u4:8/5052: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff80001fc47c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff000107f060e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0001055151b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 6 locks held by syz.4.20/5090: 5 locks held by syz.5.21/5125: 4 locks held by kworker/u4:10/5144: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff800020077c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0001059700e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000c9b691b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 6 locks held by syz.6.22/5162: 4 locks held by kworker/u4:11/5179: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff8000201f7c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0000f92cc0e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000dc06d1b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 6 locks held by syz.7.23/5197: 6 locks held by syz.8.24/5238: 3 locks held by syz-executor/5243: #0: ffff8000163bbce8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffff8000163bbce8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6d0/0xd70 net/core/rtnetlink.c:5681 #1: ffff0000f76e93e8 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_open+0x208/0x428 drivers/net/wireguard/device.c:49 #2: ffff800014465e28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #2: ffff800014465e28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x344/0x670 kernel/rcu/tree_exp.h:845 =============================================