INFO: task kworker/u4:3:18498 blocked for more than 143 seconds. Not tainted 5.15.109-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:3 state:D stack:24480 pid:18498 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:3) Call Trace: context_switch kernel/sched/core.c:5026 [inline] __schedule+0x12c4/0x4590 kernel/sched/core.c:6372 schedule+0x11b/0x1f0 kernel/sched/core.c:6455 rwsem_down_write_slowpath+0xebb/0x15c0 kernel/locking/rwsem.c:1157 __down_write_common kernel/locking/rwsem.c:1284 [inline] __down_write kernel/locking/rwsem.c:1293 [inline] down_write+0x164/0x170 kernel/locking/rwsem.c:1542 f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:529 f2fs_write_inode+0x4c3/0x540 fs/f2fs/inode.c:727 write_inode fs/fs-writeback.c:1475 [inline] __writeback_single_inode+0x644/0xe30 fs/fs-writeback.c:1680 writeback_sb_inodes+0xbf0/0x1a50 fs/fs-writeback.c:1905 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:1976 wb_writeback+0x465/0xc50 fs/fs-writeback.c:2081 wb_check_old_data_flush fs/fs-writeback.c:2181 [inline] wb_do_writeback fs/fs-writeback.c:2234 [inline] wb_workfn+0xc55/0x1130 fs/fs-writeback.c:2263 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2306 worker_thread+0xaca/0x1280 kernel/workqueue.c:2453 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c91c4e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3257: #0: ffff88814b1da098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002bb32e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1da0 drivers/tty/n_tty.c:2147 4 locks held by kworker/u4:3/18498: #0: ffff8880149f9938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2279 #1: ffffc900056afd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2281 #2: ffff88803daac0e0 (&type->s_umount_key#93){++++}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418 #3: ffff88801ab51108 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:529 3 locks held by syz-executor.3/18630: 1 lock held by syz-executor.5/20755: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.109-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb 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:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 18499 Comm: kworker/1:1 Not tainted 5.15.109-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Workqueue: events nsim_dev_trap_report_work RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:85 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x7b/0x290 mm/kasan/generic.c:189 Code: 00 00 00 00 fc ff df 4f 8d 34 1a 4c 89 f5 4c 29 cd 48 83 fd 10 7f 26 48 85 ed 0f 84 3a 01 00 00 49 f7 d2 49 01 da 41 80 39 00 <0f> 85 c4 01 00 00 49 ff c1 49 ff c2 75 ee e9 1d 01 00 00 45 89 cf RSP: 0018:ffffc900056bf618 EFLAGS: 00000246 RAX: ffff88803d5c1d01 RBX: 1ffff92000ad7ed8 RCX: ffffffff813868c2 RDX: 0000000000000001 RSI: 0000000000000060 RDI: ffffc900056bf6c0 RBP: 000000000000000c R08: dffffc0000000000 R09: fffff52000ad7eda R10: fffffffffffffff6 R11: dffffc0000000001 R12: 0000000000000000 R13: ffffffff816d9e80 R14: fffff52000ad7ee4 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000208f2030 CR3: 0000000073749000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: memset+0x1f/0x40 mm/kasan/shadow.c:44 __unwind_start+0x32/0x720 arch/x86/kernel/unwind_orc.c:632 unwind_start arch/x86/include/asm/unwind.h:60 [inline] arch_stack_walk+0xdb/0x140 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] kmem_cache_alloc_node+0x121/0x2c0 mm/slub.c:3256 __alloc_skb+0xdd/0x590 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1167 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:667 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:724 [inline] nsim_dev_trap_report_work+0x25e/0xab0 drivers/net/netdevsim/dev.c:765 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2306 worker_thread+0xaca/0x1280 kernel/workqueue.c:2453 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298