INFO: task syz.1.5547:26247 blocked for more than 143 seconds. Not tainted 6.16.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.5547 state:D stack:27384 pid:26247 tgid:26245 ppid:21301 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 io_schedule+0x81/0xe0 kernel/sched/core.c:7724 folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317 folio_wait_writeback+0xb0/0x100 mm/page-writeback.c:3126 __filemap_fdatawait_range+0x147/0x230 mm/filemap.c:539 filemap_fdatawait_keep_errors+0x31/0xd0 mm/filemap.c:633 wait_sb_inodes fs/fs-writeback.c:2714 [inline] sync_inodes_sb+0x7a9/0xa10 fs/fs-writeback.c:2836 __iterate_supers+0x13a/0x250 fs/super.c:924 ksys_sync+0x94/0x150 fs/sync.c:102 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff69818e9a9 RSP: 002b:00007ff698f14038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007ff6983b5fa0 RCX: 00007ff69818e9a9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ff6983b5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff6983b5fa0 R15: 00007ffdf05a6808 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by getty/5594: #0: ffff8880310660a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by syz.7.3760/19540: #0: ffff888025fb2428 (sb_writers#23){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3096 [inline] #0: ffff888025fb2428 (sb_writers#23){.+.+}-{0:0}, at: vfs_writev+0x288/0x960 fs/read_write.c:1055 #1: ffff888053d007b8 (&sb->s_type->i_mutex_key#30){++++}-{4:4}, at: netfs_start_io_write+0xd8/0x100 fs/netfs/locking.c:112 #2: ffff888053d00b70 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_begin_writethrough+0x65/0x140 fs/netfs/write_issue.c:626 2 locks held by syz.1.5547/26247: #0: ffff888025fb20e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888025fb20e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff888025fb2950 (&s->s_sync_lock){+.+.}-{4:4}, at: wait_sb_inodes fs/fs-writeback.c:2653 [inline] #1: ffff888025fb2950 (&s->s_sync_lock){+.+.}-{4:4}, at: sync_inodes_sb+0x255/0xa10 fs/fs-writeback.c:2836 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc7-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 25386 Comm: kworker/u8:3 Not tainted 6.16.0-rc7-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:869 [inline] RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1155 [inline] RIP: 0010:unwind_next_frame+0x1957/0x2390 arch/x86/kernel/unwind_orc.c:680 Code: c0 0f 85 9b 03 00 00 c6 03 01 4c 8b 7c 24 48 4c 8b 64 24 20 41 0f b6 04 2c 84 c0 0f 85 2d 03 00 00 41 c7 06 00 00 00 00 31 db 44 bc f3 09 85 c0 74 3a e8 db 66 34 00 84 c0 75 31 e8 32 bc f3 RSP: 0018:ffffc9001c1ff4d8 EFLAGS: 00000216 RAX: ffffc9001c200000 RBX: ffffc9001c1ff501 RCX: ffffc9001c1ff948 RDX: ffffffff903cf801 RSI: 0000000000000000 RDI: ffffc9001c1ff5b0 RBP: dffffc0000000000 R08: ffffc9001c1ff607 R09: 0000000000000000 R10: ffffc9001c1ff5f8 R11: fffff5200383fec1 R12: ffffc9001c1ff940 R13: ffffc9001c1f8000 R14: ffffc9001c1ff5a8 R15: ffffffff8172aae5 FS: 0000000000000000(0000) GS:ffff888125d57000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564db5472168 CR3: 000000000df38000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kmem_cache_free+0x18f/0x400 mm/slub.c:4745 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x7cf/0xb80 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245