INFO: task kworker/u8:8:1100 blocked for more than 143 seconds. Not tainted 6.9.0-syzkaller-10323-g8f6a15f095a6 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:8 state:D stack:11248 pid:1100 tgid:1100 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-bcachefs-1) Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x17e8/0x4a50 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 __closure_sync+0x259/0x2f0 lib/closure.c:135 closure_sync include/linux/closure.h:194 [inline] __bch2_write+0x54a5/0x5c40 fs/bcachefs/io_write.c:1495 bch2_write+0x947/0x1670 fs/bcachefs/io_write.c:1623 closure_queue include/linux/closure.h:269 [inline] closure_call include/linux/closure.h:402 [inline] bch2_writepage_do_io fs/bcachefs/fs-io-buffered.c:460 [inline] __bch2_writepage+0x1416/0x2b50 fs/bcachefs/fs-io-buffered.c:607 write_cache_pages+0xd2/0x230 mm/page-writeback.c:2591 bch2_writepages+0x14f/0x380 fs/bcachefs/fs-io-buffered.c:650 do_writepages+0x35b/0x870 mm/page-writeback.c:2634 __writeback_single_inode+0x165/0x10b0 fs/fs-writeback.c:1651 writeback_sb_inodes+0x99c/0x1380 fs/fs-writeback.c:1947 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2018 wb_writeback+0x495/0xd40 fs/fs-writeback.c:2129 wb_check_background_flush fs/fs-writeback.c:2199 [inline] wb_do_writeback fs/fs-writeback.c:2287 [inline] wb_workfn+0xc58/0x1090 fs/fs-writeback.c:2314 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8e333d20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 3 locks held by kworker/u8:8/1100: #0: ffff888018ee3948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff888018ee3948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc9000420fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc9000420fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffff88802281e0e0 (&type->s_umount_key#43){.+.+}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 2 locks held by getty/4844: #0: ffff88802b1e40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f0e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201 2 locks held by syz-executor368/5417: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 30 Comm: khungtaskd Not tainted 6.9.0-syzkaller-10323-g8f6a15f095a6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xfde/0x1020 kernel/hung_task.c:379 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5092 Comm: udevd Not tainted 6.9.0-syzkaller-10323-g8f6a15f095a6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:kasan_check_range+0x1b8/0x290 mm/kasan/generic.c:189 Code: 4d 01 fb 48 8d 5d 07 48 85 ed 48 0f 49 dd 48 83 e3 f8 48 29 dd 74 12 41 80 3b 00 0f 85 a6 00 00 00 49 ff c3 48 ff cd 75 ee 5b <41> 5c 41 5e 41 5f 5d e9 a7 4c b4 09 40 84 ed 75 5f f7 c5 00 ff 00 RSP: 0018:ffffc900030b7c50 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff84e9483e RDX: 0000000000000001 RSI: 0000000000000fe0 RDI: ffff888025802220 RBP: 0000000000000000 R08: ffff8880258031ff R09: 1ffff11004b0063f R10: dffffc0000000000 R11: ffffed1004b00640 R12: 0000000000000004 R13: 00007ffd45fcc838 R14: dffffc0000000001 R15: 00000000000001f8 FS: 00007fa02b49bc80(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc10f9ff000 CR3: 00000000201b2000 CR4: 0000000000350ef0 Call Trace: strncpy_from_user+0x9e/0x2f0 lib/strncpy_from_user.c:136 getname_flags+0xfa/0x4f0 fs/namei.c:150 vfs_fstatat+0x11c/0x190 fs/stat.c:303 __do_sys_newfstatat fs/stat.c:468 [inline] __se_sys_newfstatat fs/stat.c:462 [inline] __x64_sys_newfstatat+0x125/0x1b0 fs/stat.c:462 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa02b1165f4 Code: 64 c7 00 09 00 00 00 83 c8 ff c3 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 00 00 00 00 41 89 ca b8 06 01 00 00 0f 05 <45> 31 c0 3d 00 f0 ff ff 76 10 48 8b 15 03 a8 0d 00 f7 d8 41 83 c8 RSP: 002b:00007ffd45fcc398 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00005580866562a0 RCX: 00007fa02b1165f4 RDX: 00007ffd45fcc3a8 RSI: 00007ffd45fcc838 RDI: 00000000ffffff9c RBP: 00007ffd45fcc438 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd45fcc838 R13: 00007ffd45fcc3a8 R14: 0000558086642910 R15: 000055804dab4a04 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.323 msecs