INFO: task syz-executor:3641 blocked for more than 143 seconds. Not tainted 6.1.108-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20536 pid:3641 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0xac/0x300 kernel/time/timer.c:1941 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x350/0x610 kernel/sched/completion.c:138 kthread_stop+0x1ab/0x690 kernel/kthread.c:709 ext4_stop_mmpd+0x43/0xb0 fs/ext4/mmp.c:261 ext4_put_super+0xb49/0x10e0 fs/ext4/super.c:1293 generic_shutdown_super+0x130/0x340 fs/super.c:501 kill_block_super+0x7a/0xe0 fs/super.c:1470 deactivate_locked_super+0xa0/0x110 fs/super.c:332 cleanup_mnt+0x490/0x520 fs/namespace.c:1186 task_work_run+0x246/0x300 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f00e217e227 RSP: 002b:00007ffc3c57cc18 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f00e21eeee4 RCX: 00007f00e217e227 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc3c57ccd0 RBP: 00007ffc3c57ccd0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc3c57dd50 R13: 00007f00e21eeee4 R14: 0000000000011106 R15: 00007ffc3c57dd90 INFO: task kmmpd-loop2:3875 blocked for more than 144 seconds. Not tainted 6.1.108-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kmmpd-loop2 state:D stack:27424 pid:3875 ppid:2 flags:0x00024000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 percpu_rwsem_wait+0x3b9/0x450 kernel/locking/percpu-rwsem.c:162 __percpu_down_read+0xe6/0x130 kernel/locking/percpu-rwsem.c:177 percpu_down_read include/linux/percpu-rwsem.h:65 [inline] __sb_start_write include/linux/fs.h:1891 [inline] sb_start_write include/linux/fs.h:1966 [inline] write_mmp_block+0x2ee/0x390 fs/ext4/mmp.c:66 kmmpd+0x263/0xa70 fs/ext4/mmp.c:246 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d32b190 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d32b990 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8d32afc0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d32afc0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d32afc0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494 1 lock held by dhcpcd/3304: #0: ffff8880b8e3a9d8 (&rq->__lock){-.-.}-{2:2}, at: __unix_dgram_recvmsg+0x24d/0x1260 net/unix/af_unix.c:2431 2 locks held by getty/3394: #0: ffff88814b013098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198 1 lock held by syz-executor/3641: #0: ffff88805797c0e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 1 lock held by syz-executor/3643: #0: ffff8880294a80e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 1 lock held by syz-executor/3645: #0: ffff8880563cc0e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 1 lock held by kmmpd-loop2/3875: #0: ffff88805797c460 (sb_writers#4){++++}-{0:0}, at: kmmpd+0x263/0xa70 fs/ext4/mmp.c:246 1 lock held by kmmpd-loop3/3990: #0: ffff8880294a8460 (sb_writers#4){++++}-{0:0}, at: kmmpd+0x263/0xa70 fs/ext4/mmp.c:246 1 lock held by kmmpd-loop4/4023: #0: ffff8880563cc460 (sb_writers#4){++++}-{0:0}, at: kmmpd+0x263/0xa70 fs/ext4/mmp.c:246 2 locks held by syz.0.92/4078: #0: ffff888078a4c460 (sb_writers#3){.+.+}-{0:0}, at: do_sendfile+0x5f4/0xff0 fs/read_write.c:1254 #1: ffff88805797c0e0 (&type->s_umount_key#31){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 6.1.108-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1ae/0x3f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf88/0xfd0 kernel/hung_task.c:377 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3080 Comm: klogd Not tainted 6.1.108-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:check_preemption_disabled+0x6/0x110 lib/smp_processor_id.c:13 Code: de e8 0e f1 bd f9 e9 6d ff ff ff cc cc cc cc cc cc cc cc cc 48 c7 c7 60 69 5d 8b 48 c7 c6 a0 69 5d 8b eb 00 41 57 41 56 41 54 <53> 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 8b 1d RSP: 0018:ffffc9000314f6f0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff816b3c52 RDX: dffffc0000000000 RSI: ffffffff8b0c13e0 RDI: ffffffff8b5d69c0 RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff223b645 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000046 R13: ffff88807ced9dc0 R14: 00000000ffffffff R15: ffff8880b8e43ef0 FS: 00007f38675a0380(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056150a2bfa18 CR3: 000000007e648000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline] lock_is_held_type+0xfd/0x180 kernel/locking/lockdep.c:5706 lock_is_held include/linux/lockdep.h:283 [inline] get_freelist mm/slub.c:3013 [inline] ___slab_alloc+0x2a6/0x1270 mm/slub.c:3108 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] kmem_cache_alloc_node+0x1cf/0x310 mm/slub.c:3443 __alloc_skb+0xde/0x670 net/core/skbuff.c:505 alloc_skb include/linux/skbuff.h:1271 [inline] alloc_skb_with_frags+0xa4/0x740 net/core/skbuff.c:6162 sock_alloc_send_pskb+0x915/0xa50 net/core/sock.c:2747 unix_dgram_sendmsg+0x5b1/0x2050 net/unix/af_unix.c:1925 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] __sys_sendto+0x480/0x600 net/socket.c:2148 __do_sys_sendto net/socket.c:2160 [inline] __se_sys_sendto net/socket.c:2156 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2156 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f38677029b5 Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffd82f87418 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f38677029b5 RDX: 0000000000000047 RSI: 000055ec7ca65c10 RDI: 0000000000000003 RBP: 000055ec7ca5f910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013 R13: 00007f3867890212 R14: 00007ffd82f87518 R15: 0000000000000000