INFO: task kworker/u4:5:1611 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack: 0 pid: 1611 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 rwsem_down_write_slowpath+0xcb8/0x13f4 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+0x3a4/0x650 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+0x560/0x11f0 fs/fs-writeback.c:1715 writeback_sb_inodes+0x7fc/0x1378 fs/fs-writeback.c:1940 __writeback_inodes_wb+0x110/0x394 fs/fs-writeback.c:2011 wb_writeback+0x3ec/0xe44 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+0xa7c/0xdd8 fs/fs-writeback.c:2298 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: 1 lock held by khungtaskd/27: #0: ffff8000142f1520 (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+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff80001b767c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000cb56a0e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000d6f251b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3a4/0x650 fs/f2fs/segment.c:528 4 locks held by kworker/u4:2/148: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff80001be27c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000f5a2a0e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000de0451b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3a4/0x650 fs/f2fs/segment.c:528 4 locks held by kworker/u4:3/385: #0: ffff0000c1e37938 ((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: ffff0000d60660e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000dda651b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3a4/0x650 fs/f2fs/segment.c:528 2 locks held by kworker/0:2/1540: #0: ffff0000c0021938 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff8000235d7c00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 4 locks held by kworker/u4:4/1605: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff800023b37c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000f1df80e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff000103aa51b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3a4/0x650 fs/f2fs/segment.c:528 4 locks held by kworker/u4:5/1611: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff8000234a7c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000cb4500e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000cd0bd1b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3a4/0x650 fs/f2fs/segment.c:528 2 locks held by getty/3801: #0: ffff0000d0a6b098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340 #1: ffff80001b7f62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x2f0/0xf6c drivers/tty/n_tty.c:2158 5 locks held by syz.0.16/4954: 6 locks held by syz.1.17/4982: 8 locks held by syz.2.18/5009: 4 locks held by kworker/u4:6/5028: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff800020087c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000f902e0e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000f61cd1b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3a4/0x650 fs/f2fs/segment.c:528 5 locks held by syz.3.19/5034: 4 locks held by kworker/u4:8/5039: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff80001ff07c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff000104a640e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff000104a111b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3a4/0x650 fs/f2fs/segment.c:528 7 locks held by syz.4.20/5078: 6 locks held by syz.5.21/5113: 4 locks held by kworker/u4:11/5139: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff800020517c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000f32380e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000d94e51b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3a4/0x650 fs/f2fs/segment.c:528 4 locks held by syz.6.22/5150: 7 locks held by syz.7.23/5186: 6 locks held by syz.8.24/5227: 4 locks held by kworker/u4:13/5230: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283 #1: ffff800020807c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285 #2: ffff0000d9bb60e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000d069d1b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3a4/0x650 fs/f2fs/segment.c:528 2 locks held by syz-executor/5233: #0: ffff800016249568 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffff800016249568 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6ec/0xce4 net/core/rtnetlink.c:5681 #1: ffff8000142f5fe8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffff8000142f5fe8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2f0/0x5e0 kernel/rcu/tree_exp.h:845 =============================================