INFO: task syz-executor:21216 blocked for more than 143 seconds. Not tainted 6.14.0-syzkaller-01103-g2df0c02dab82 #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21192 pid:21216 tgid:21216 ppid:1 task_flags:0x40014c flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5367 [inline] __schedule+0x1b18/0x50e0 kernel/sched/core.c:6748 __schedule_loop kernel/sched/core.c:6825 [inline] schedule+0x163/0x360 kernel/sched/core.c:6840 wb_wait_for_completion+0x166/0x270 fs/fs-writeback.c:216 sync_inodes_sb+0x28f/0xb50 fs/fs-writeback.c:2821 sync_filesystem+0x176/0x230 fs/sync.c:64 generic_shutdown_super+0x72/0x2d0 fs/super.c:621 kill_block_super+0x44/0x90 fs/super.c:1710 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7368 deactivate_locked_super+0xc6/0x130 fs/super.c:473 cleanup_mnt+0x422/0x4c0 fs/namespace.c:1435 task_work_run+0x253/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2a/0x2940 kernel/exit.c:954 do_group_exit+0x207/0x2c0 kernel/exit.c:1103 __do_sys_exit_group kernel/exit.c:1114 [inline] __se_sys_exit_group kernel/exit.c:1112 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1112 x64_sys_call+0x26c3/0x26d0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe3a698d169 RSP: 002b:00007fff08246588 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fe3a6a0e0fe RCX: 00007fe3a698d169 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000010 R08: 00007fff08244326 R09: 00007fff08247840 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff08247840 R13: 00007fe3a6a0e08c R14: 00005555819e14a8 R15: 00007fff08248910 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8eb3a760 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8eb3a760 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8eb3a760 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6761 2 locks held by getty/5602: #0: ffff88803545a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000331b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x53d/0x16b0 drivers/tty/n_tty.c:2211 3 locks held by kworker/u8:17/8260: 3 locks held by kworker/0:4/15428: #0: ffff88801ac78d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801ac78d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90003437c60 (key_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003437c60 (key_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8eb3fc78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #2: ffffffff8eb3fc78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x454/0x830 kernel/rcu/tree_exp.h:998 2 locks held by syz-executor/21216: #0: ffff888024c660e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff888024c660e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888024c660e0 (&type->s_umount_key#31){++++}-{4:4}, at: deactivate_super+0xb5/0xf0 fs/super.c:505 #1: ffff88802527a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802527a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x270/0xb50 fs/fs-writeback.c:2819 1 lock held by syz.6.3901/22998: #0: ffff888024c660e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888024c660e0 (&type->s_umount_key#31){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 1 lock held by syz.7.4026/23574: #0: ffff888024c660e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888024c660e0 (&type->s_umount_key#31){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 2 locks held by syz.2.4214/24313: #0: ffff888078b90208 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #0: ffff888078b90208 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline] #0: ffff888078b90208 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: sock_close+0x90/0x240 net/socket.c:1398 #1: ffffffff8eb3fc78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #1: ffffffff8eb3fc78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x384/0x830 kernel/rcu/tree_exp.h:998 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-syzkaller-01103-g2df0c02dab82 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8260 Comm: kworker/u8:17 Not tainted 6.14.0-syzkaller-01103-g2df0c02dab82 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: writeback wb_workfn (flush-7:3) RIP: 0010:page_ref_add_unless include/linux/page_ref.h:237 [inline] RIP: 0010:folio_ref_add_unless include/linux/page_ref.h:248 [inline] RIP: 0010:folio_try_get+0x101/0x350 include/linux/page_ref.h:264 Code: 00 00 e8 42 ad 2e 00 4c 89 fd 48 c1 ed 03 42 0f b6 44 25 00 84 c0 0f 85 50 01 00 00 41 8b 1f 31 ff 89 de e8 f1 8f c6 ff 85 db <0f> 84 8c 00 00 00 4c 89 ff be 04 00 00 00 e8 3c ad 2e 00 42 0f b6 RSP: 0018:ffffc900050be7c8 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000002 RCX: ffffffff81fcd6fe RDX: ffff8880278f1e00 RSI: 0000000000000002 RDI: 0000000000000000 RBP: 1ffffd40002bf3c6 R08: ffffffff81fcd71f R09: 1ffffd40002bf3c6 R10: dffffc0000000000 R11: fffff940002bf3c7 R12: dffffc0000000000 R13: 0007ffffffffffff R14: ffffffff81fcd63e R15: ffffea00015f9e34 FS: 0000000000000000(0000) GS:ffff888125224000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2cb5379178 CR3: 000000005d4a0000 CR4: 0000000000350ef0 Call Trace: find_get_entry mm/filemap.c:2039 [inline] filemap_get_folios_tag+0x31e/0x790 mm/filemap.c:2294 mpage_prepare_extent_to_map+0x5a2/0x1870 fs/ext4/inode.c:2448 ext4_do_writepages+0xc2c/0x3e00 fs/ext4/inode.c:2688 ext4_writepages+0x203/0x3c0 fs/ext4/inode.c:2824 do_writepages+0x36c/0x890 mm/page-writeback.c:2687 __writeback_single_inode+0x14f/0x10d0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x822/0x1360 fs/fs-writeback.c:1976 wb_writeback+0x415/0xb90 fs/fs-writeback.c:2156 wb_do_writeback fs/fs-writeback.c:2303 [inline] wb_workfn+0x412/0x10b0 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac5/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245