INFO: task syz-executor.0:5484 blocked for more than 143 seconds. Not tainted 6.7.0-next-20240112-syzkaller-13343-g8d04a7e2ee3f #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:28800 pid:5484 tgid:5477 ppid:5417 flags:0x00000006 Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0xf15/0x5ce0 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0xe7/0x280 kernel/sched/core.c:6817 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6874 rwsem_down_write_slowpath kernel/locking/rwsem.c:1178 [inline] __down_write_common+0x950/0x13f0 kernel/locking/rwsem.c:1306 inode_lock_nested include/linux/fs.h:837 [inline] fuse_reverse_inval_entry+0x59/0x580 fs/fuse/dir.c:1351 fuse_notify_delete fs/fuse/dev.c:1552 [inline] fuse_notify fs/fuse/dev.c:1801 [inline] fuse_dev_do_write+0xe98/0x2c90 fs/fuse/dev.c:1876 fuse_dev_write+0x155/0x1e0 fs/fuse/dev.c:1960 call_write_iter include/linux/fs.h:2085 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6db/0x1100 fs/read_write.c:590 ksys_write+0x12f/0x260 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7fc213e7ad39 RSP: 002b:00007fc214fd20c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc213f9c050 RCX: 00007fc213e7ad39 RDX: 000000000000002c RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007fc213ed7567 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007fc213f9c050 R15: 00007ffec8405158 Showing all locks held in the system: 3 locks held by kworker/u4:1/12: #0: ffff8880b953ccd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559 #1: ffff8880b9528a08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2d9/0x900 kernel/sched/psi.c:988 #2: ffff8880b9529958 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x5d/0x200 kernel/time/timer.c:999 1 lock held by khungtaskd/29: #0: ffffffff8d7aeca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8d7aeca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8d7aeca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614 2 locks held by getty/4817: #0: ffff88802bada0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2201 1 lock held by syz-executor.0/5417: #0: ffff888076918150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:812 [inline] #0: ffff888076918150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow fs/namei.c:1709 [inline] #0: ffff888076918150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: walk_component+0x342/0x5b0 fs/namei.c:2001 2 locks held by syz-executor.0/5478: #0: ffff888076918150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:812 [inline] #0: ffff888076918150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow fs/namei.c:1709 [inline] #0: ffff888076918150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: walk_component+0x342/0x5b0 fs/namei.c:2001 #1: ffff8880769185c8 (&fi->mutex){+.+.}-{3:3}, at: fuse_lock_inode+0xd2/0x110 fs/fuse/inode.c:544 2 locks held by syz-executor.0/5484: #0: ffff88802c2f8338 (&fc->killsb){.+.+}-{3:3}, at: fuse_notify_delete fs/fuse/dev.c:1551 [inline] #0: ffff88802c2f8338 (&fc->killsb){.+.+}-{3:3}, at: fuse_notify fs/fuse/dev.c:1801 [inline] #0: ffff88802c2f8338 (&fc->killsb){.+.+}-{3:3}, at: fuse_dev_do_write+0xe78/0x2c90 fs/fuse/dev.c:1876 #1: ffff888076918150 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:837 [inline] #1: ffff888076918150 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: fuse_reverse_inval_entry+0x59/0x580 fs/fuse/dir.c:1351 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.7.0-next-20240112-syzkaller-13343-g8d04a7e2ee3f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf86/0x1210 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4493 Comm: syslogd Not tainted 6.7.0-next-20240112-syzkaller-13343-g8d04a7e2ee3f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 RIP: 0010:unwind_next_frame+0x11a2/0x2390 arch/x86/kernel/unwind_orc.c:665 Code: e8 a3 00 50 00 41 39 ec 0f 85 b1 00 00 00 e8 75 06 50 00 48 8b 54 24 10 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 <0f> 85 b5 11 00 00 48 8d 7b 08 48 8b 6b 38 48 b8 00 00 00 00 00 fc RSP: 0018:ffffc9000331f548 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffffc9000331f5c8 RCX: ffffffff813c16cd RDX: 1ffff92000663ec0 RSI: ffffffff813c16db RDI: 0000000000000004 RBP: 0000000000000001 R08: 0000000000000004 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000001 R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000001 FS: 00007f8640aed380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555ce742c680 CR3: 000000007bfdc000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x100/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3f/0x60 mm/kasan/generic.c:640 poison_slab_object mm/kasan/common.c:241 [inline] __kasan_slab_free+0x121/0x1c0 mm/kasan/common.c:257 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2121 [inline] slab_free mm/slub.c:4299 [inline] kmem_cache_free+0x12e/0x360 mm/slub.c:4363 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:1051 __kfree_skb net/core/skbuff.c:1109 [inline] consume_skb net/core/skbuff.c:1324 [inline] consume_skb+0xdf/0x170 net/core/skbuff.c:1318 __unix_dgram_recvmsg+0x814/0xef0 net/unix/af_unix.c:2468 unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2485 sock_recvmsg_nosec net/socket.c:1046 [inline] sock_recvmsg+0x1f6/0x250 net/socket.c:1068 sock_read_iter+0x2c7/0x3c0 net/socket.c:1138 call_read_iter include/linux/fs.h:2079 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0x9fd/0xb80 fs/read_write.c:476 ksys_read+0x1f8/0x260 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7f8640c41b6a Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007fff473f6968 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f8640c41b6a RDX: 00000000000000ff RSI: 000055b76967d950 RDI: 0000000000000000 RBP: 000055b76967d910 R08: 0000000000000001 R09: 0000000000000000 R10: 00007f8640de03a3 R11: 0000000000000246 R12: 000055b76967d99c R13: 000055b76967d950 R14: 0000000000000000 R15: 00007f8640e1ea80