INFO: task syz-executor:7270 blocked for more than 143 seconds. Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21816 pid:7270 tgid:7270 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216 __writeback_inodes_sb_nr+0x1f6/0x250 fs/fs-writeback.c:2747 sync_filesystem+0xa3/0x230 fs/sync.c:54 generic_shutdown_super+0x6f/0x2c0 fs/super.c:621 bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2625 deactivate_locked_super+0xb9/0x130 fs/super.c:473 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1435 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work+0x5e/0x80 include/linux/resume_user_mode.h:50 exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x9a/0x120 kernel/entry/common.c:218 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fec6498fc97 RSP: 002b:00007ffdfc423be8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fec64a1089d RCX: 00007fec6498fc97 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdfc423ca0 RBP: 00007ffdfc423ca0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffdfc424d30 R13: 00007fec64a1089d R14: 000000000003db6e R15: 00007ffdfc424d70 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 2 locks held by kworker/u8:4/59: #0: ffff88801ca8e148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] ffff88801ca8e148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc9000125fc60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000125fc60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 4 locks held by kworker/u8:5/194: 3 locks held by kworker/u8:7/1318: 2 locks held by getty/5569: #0: ffff88814e4430a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002ffe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5818: #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 5 locks held by udevd/5986: 1 lock held by syz-executor/7270: #0: ffff8880286720e0 (&type->s_umount_key#88){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880286720e0 (&type->s_umount_key#88){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880286720e0 (&type->s_umount_key#88){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 2 locks held by bch-copygc/loop/8246: 2 locks held by syz.4.471/11079: 1 lock held by syz.2.472/11033: #0: ffff88806eb460e0 (&type->s_umount_key#54/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970 fs/super.c:344 2 locks held by dhcpcd/11045: #0: ffff88805dcda008 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #0: ffff88805dcda008 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline] #0: ffff88805dcda008 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1391 #1: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #1: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 1 lock held by dhcpcd/11068: #0: ffff88805dcdd008 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #0: ffff88805dcdd008 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline] #0: ffff88805dcdd008 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1391 1 lock held by udevadm/11094: 4 locks held by dhcpcd-run-hook/11100: #0: ffff8880b89399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605 #1: ffff8880b8923b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987 #2: ffff8880348e89d8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffff8880348e89d8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: __pte_offset_map_lock+0x106/0x1e0 mm/pgtable-generic.c:402 #3: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #3: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #3: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: page_table_check_set+0x16b/0x710 mm/page_table_check.c:112 1 lock held by udevadm/11102: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 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:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/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: 11033 Comm: syz.2.472 Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x8/0x90 kernel/kcov.c:321 Code: 48 89 44 11 20 c3 cc cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 10 72 92 65 8b 15 d8 4b b2 10 81 e2 00 01 ff 00 RSP: 0018:ffffc9000b787418 EFLAGS: 00000246 RAX: ffffffff8206ad0a RBX: ffffea0001aec0c8 RCX: ffff88802c125a00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000b7876b0 R08: ffffea0001aec0b3 R09: 1ffffd400035d816 R10: dffffc0000000000 R11: fffff9400035d817 R12: ffffea0001aec0c0 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff888070408d30 FS: 0000000000000000(0000) GS:ffff8881260ff000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056315976a950 CR3: 0000000026a22000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: const_folio_flags include/linux/page-flags.h:347 [inline] folio_test_head include/linux/page-flags.h:860 [inline] folio_test_large include/linux/page-flags.h:881 [inline] zap_present_ptes mm/memory.c:1577 [inline] do_zap_pte_range mm/memory.c:1687 [inline] zap_pte_range mm/memory.c:1731 [inline] zap_pmd_range mm/memory.c:1823 [inline] zap_pud_range mm/memory.c:1852 [inline] zap_p4d_range mm/memory.c:1873 [inline] unmap_page_range+0x12da/0x4210 mm/memory.c:1894 unmap_vmas+0x25d/0x3c0 mm/memory.c:1984 exit_mmap+0x245/0xba0 mm/mmap.c:1284 __mmput+0x118/0x410 kernel/fork.c:1379 exit_mm+0x1da/0x2c0 kernel/exit.c:589 do_exit+0x859/0x2550 kernel/exit.c:940 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x125e/0x1310 kernel/signal.c:3034 arch_do_signal_or_restart+0x95/0x780 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x8b/0x120 kernel/entry/common.c:218 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0a2779010a Code: Unable to access opcode bytes at 0x7f0a277900e0. RSP: 002b:00007f0a286d5e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: 0000000000000000 RBX: 00007f0a286d5ef0 RCX: 00007f0a2779010a RDX: 0000200000000000 RSI: 0000200000000040 RDI: 00007f0a286d5eb0 RBP: 0000200000000000 R08: 00007f0a286d5ef0 R09: 0000000000800810 R10: 0000000000800810 R11: 0000000000000246 R12: 0000200000000040 R13: 00007f0a286d5eb0 R14: 00000000000050f9 R15: 0000200000000240