INFO: task kworker/u8:2:35 blocked for more than 143 seconds. Not tainted 6.10.0-rc5-syzkaller-00018-g55027e689933 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:2 state:D stack:19640 pid:35 tgid:35 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:2) Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x1796/0x49d0 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6894 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 exfat_write_inode+0x69/0x120 fs/exfat/inode.c:105 write_inode fs/fs-writeback.c:1497 [inline] __writeback_single_inode+0x6b9/0x10b0 fs/fs-writeback.c:1716 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+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 4 locks held by kworker/u8:2/35: #0: ffff88801928c948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff88801928c948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc90000ab7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc90000ab7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffff88802b0f60e0 (&type->s_umount_key#74){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff88802b0f20e0 (&sbi->s_lock#3){+.+.}-{3:3}, at: exfat_write_inode+0x69/0x120 fs/exfat/inode.c:105 2 locks held by kworker/u8:5/1035: 5 locks held by kworker/u8:10/2842: 2 locks held by getty/4842: #0: ffff88802a51d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2211 3 locks held by syz-executor/5186: 3 locks held by syz-executor/5913: 1 lock held by syz-executor/6025: #0: ffffffff8e339378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #0: ffffffff8e339378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:939 2 locks held by syz.2.451/7238: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 30 Comm: khungtaskd Not tainted 6.10.0-rc5-syzkaller-00018-g55027e689933 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 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+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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: 6364 Comm: syz-executor Not tainted 6.10.0-rc5-syzkaller-00018-g55027e689933 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline] RIP: 0010:deref_stack_reg+0x32/0x260 arch/x86/kernel/unwind_orc.c:403 Code: 54 53 48 83 ec 28 49 89 d6 48 89 34 24 48 89 fb 49 bf 00 00 00 00 00 fc ff df e8 39 07 55 00 48 8d 6b 08 49 89 ec 49 c1 ec 03 <43> 80 3c 3c 00 74 08 48 89 ef e8 9f 6a b7 00 48 89 6c 24 10 4c 89 RSP: 0018:ffffc90002f9f520 EFLAGS: 00000a02 RAX: ffffffff81411d67 RBX: ffffc90002f9f6c0 RCX: ffff888068150000 RDX: 0000000000000000 RSI: ffffc90002f9f6b0 RDI: ffffc90002f9f6c0 RBP: ffffc90002f9f6c8 R08: 0000000000000005 R09: ffffffff8141095f R10: 0000000000000003 R11: ffff888068150000 R12: 1ffff920005f3ed9 R13: dffffc0000000000 R14: ffffc90002f9f700 R15: dffffc0000000000 FS: 0000555572288500(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faa038356dd CR3: 000000004afa0000 CR4: 00000000003506f0 Call Trace: unwind_next_frame+0x1ab8/0x2a00 arch/x86/kernel/unwind_orc.c:648 __unwind_start+0x641/0x7c0 arch/x86/kernel/unwind_orc.c:760 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x103/0x1b0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slub.c:4122 [inline] __kmalloc_noprof+0x1f9/0x400 mm/slub.c:4135 kmalloc_noprof include/linux/slab.h:664 [inline] kzalloc_noprof include/linux/slab.h:778 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x26f/0x540 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x59e/0x5e0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x23a/0x880 security/tomoyo/file.c:723 security_file_ioctl+0x75/0xb0 security/security.c:2765 __do_sys_ioctl fs/ioctl.c:901 [inline] __se_sys_ioctl+0x47/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f891757593b Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007fffadbb0260 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000955 RCX: 00007f891757593b RDX: 00007fffadbb02d8 RSI: 0000000040086602 RDI: 0000000000000005 RBP: 00007fffadbb0370 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffadbb1420 R13: 00007f89175e3672 R14: 00005555722884a8 R15: 0000000000000005