INFO: task syz.7.87:6819 blocked for more than 143 seconds. Not tainted 6.12.0-syzkaller-10689-g7af08b57bcb9 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.87 state:D stack:27360 pid:6819 tgid:6803 ppid:6020 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 d_wait_lookup fs/dcache.c:2477 [inline] d_alloc_parallel+0xc16/0x1600 fs/dcache.c:2559 lookup_open fs/namei.c:3571 [inline] open_last_lookups fs/namei.c:3748 [inline] path_openat+0x9e6/0x3590 fs/namei.c:3984 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_openat fs/open.c:1433 [inline] __se_sys_openat fs/open.c:1428 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1428 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: 0033:0x7fb4c8780809 RSP: 002b:00007fb4c9526058 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fb4c8946240 RCX: 00007fb4c8780809 RDX: 0000000000000000 RSI: 0000000020004280 RDI: ffffffffffffff9c RBP: 00007fb4c87f393e R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000000d4 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fb4c8946240 R15: 00007ffc15486fe8 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e93c560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e93c560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e93c560 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744 6 locks held by kworker/u8:6/1328: 1 lock held by klogd/5203: #0: ffff8880b863e758 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598 2 locks held by getty/5593: #0: ffff88814dd200a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by syz.7.87/6804: 1 lock held by syz.7.87/6807: 1 lock held by syz.7.87/6818: #0: ffff888079acc180 (&type->i_mutex_dir_key#22){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:828 [inline] #0: ffff888079acc180 (&type->i_mutex_dir_key#22){.+.+}-{4:4}, at: lookup_slow+0x45/0x70 fs/namei.c:1807 1 lock held by syz.7.87/6819: #0: ffff888079acc180 (&type->i_mutex_dir_key#22){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:828 [inline] #0: ffff888079acc180 (&type->i_mutex_dir_key#22){.+.+}-{4:4}, at: open_last_lookups fs/namei.c:3747 [inline] #0: ffff888079acc180 (&type->i_mutex_dir_key#22){.+.+}-{4:4}, at: path_openat+0x88b/0x3590 fs/namei.c:3984 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-syzkaller-10689-g7af08b57bcb9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 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:234 [inline] watchdog+0xff6/0x1040 kernel/hung_task.c:397 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6818 Comm: syz.7.87 Not tainted 6.12.0-syzkaller-10689-g7af08b57bcb9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:check_preemption_disabled+0x2e/0x120 Code: 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 8b 1d ec 99 39 74 65 8b 05 e1 99 39 74 a9 ff ff ff 7f 74 26 <65> 48 8b 04 25 28 00 00 00 48 3b 44 24 08 0f 85 ce 00 00 00 89 d8 RSP: 0018:ffffc9000438f048 EFLAGS: 00000046 RAX: 0000000080000000 RBX: 0000000000000001 RCX: ffffffff8171934a RDX: dffffc0000000000 RSI: ffffffff8c0aeb60 RDI: ffffffff8c608460 RBP: ffffc9000438f128 R08: ffffffff942ee9ef R09: 1ffffffff285dd3d R10: dffffc0000000000 R11: fffffbfff285dd3e R12: ffff888028000b28 R13: 0000000000000001 R14: ffff888028000ad8 R15: 1ffff1100500015b FS: 00007fb4c95476c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005641addc7600 CR3: 000000005b190000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline] lockdep_hardirqs_on_prepare+0x43d/0x780 kernel/locking/lockdep.c:4407 trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:47 lookup_bh_lru fs/buffer.c:1382 [inline] __find_get_block+0x573/0x1150 fs/buffer.c:1394 bdev_getblk+0x33/0x550 fs/buffer.c:1425 __bread_gfp+0x86/0x400 fs/buffer.c:1485 sb_bread include/linux/buffer_head.h:346 [inline] get_branch+0x2c3/0x6e0 fs/sysv/itree.c:102 get_block+0x180/0x16d0 fs/sysv/itree.c:222 block_read_full_folio+0x418/0xcd0 fs/buffer.c:2396 filemap_read_folio+0x14b/0x630 mm/filemap.c:2366 do_read_cache_folio+0x3f5/0x850 mm/filemap.c:3826 read_mapping_folio include/linux/pagemap.h:1011 [inline] dir_get_folio fs/sysv/dir.c:64 [inline] sysv_find_entry+0x16a/0x4b0 fs/sysv/dir.c:154 sysv_inode_by_name+0x98/0x2a0 fs/sysv/dir.c:370 sysv_lookup+0x6b/0xe0 fs/sysv/namei.c:38 __lookup_slow+0x28c/0x3f0 fs/namei.c:1791 lookup_slow+0x53/0x70 fs/namei.c:1808 walk_component+0x2e1/0x410 fs/namei.c:2112 lookup_last fs/namei.c:2610 [inline] path_lookupat+0x16f/0x450 fs/namei.c:2634 filename_lookup+0x2a3/0x670 fs/namei.c:2663 user_path_at+0x3a/0x60 fs/namei.c:3070 do_mount fs/namespace.c:3844 [inline] __do_sys_mount fs/namespace.c:4057 [inline] __se_sys_mount+0x297/0x3c0 fs/namespace.c:4034 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: 0033:0x7fb4c8780809 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb4c9547058 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fb4c8946160 RCX: 00007fb4c8780809 RDX: 0000000020000340 RSI: 0000000020000300 RDI: 00000000200002c0 RBP: 00007fb4c87f393e R08: 0000000020000380 R09: 0000000000000000 R10: 0000000000010000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fb4c8946160 R15: 00007ffc15486fe8