netlink: 'syz-executor.4': attribute type 21 has an invalid length.
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 1
======================================================
WARNING: possible circular locking dependency detected
6.1.67-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.4/3715 is trying to acquire lock:
ffffffff8d11e640 (console_owner){....}-{0:0}, at: console_lock_spinning_enable kernel/printk/printk.c:1805 [inline]
ffffffff8d11e640 (console_owner){....}-{0:0}, at: console_emit_next_record+0x9fa/0xea0 kernel/printk/printk.c:2739

but task is already holding lock:
ffff8880b9939e18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&rq->__lock){-.-.}-{2:2}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
       raw_spin_rq_lock kernel/sched/sched.h:1354 [inline]
       rq_lock kernel/sched/sched.h:1644 [inline]
       task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11863
       sched_cgroup_fork+0x374/0x400 kernel/sched/core.c:4686
       copy_process+0x2442/0x4060 kernel/fork.c:2384
       kernel_clone+0x222/0x920 kernel/fork.c:2682
       user_mode_thread+0x12e/0x190 kernel/fork.c:2758
       rest_init+0x23/0x300 init/main.c:696
       start_kernel+0x0/0x53f init/main.c:891
       start_kernel+0x496/0x53f init/main.c:1138
       secondary_startup_64_no_verify+0xcf/0xdb

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
       try_to_wake_up+0xad/0x12e0 kernel/sched/core.c:4112
       __wake_up_common+0x2a0/0x4e0 kernel/sched/wait.c:107
       __wake_up_common_lock kernel/sched/wait.c:138 [inline]
       __wake_up+0x11a/0x1c0 kernel/sched/wait.c:160
       tty_port_default_wakeup+0xa2/0xf0 drivers/tty/tty_port.c:71
       serial8250_tx_chars+0x60d/0x800 drivers/tty/serial/8250/8250_port.c:1860
       serial8250_handle_irq+0x4ff/0x6a0 drivers/tty/serial/8250/8250_port.c:1967
       serial8250_default_handle_irq+0xc8/0x1e0 drivers/tty/serial/8250/8250_port.c:1987
       serial8250_interrupt+0xa1/0x1e0 drivers/tty/serial/8250/8250_core.c:126
       __handle_irq_event_percpu+0x2a8/0xb20 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x85/0x1e0 kernel/irq/handle.c:210
       handle_edge_irq+0x245/0xbf0 kernel/irq/chip.c:819
       generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
       handle_irq arch/x86/kernel/irq.c:231 [inline]
       __common_interrupt+0xd7/0x1f0 arch/x86/kernel/irq.c:250
       common_interrupt+0x9f/0xc0 arch/x86/kernel/irq.c:240
       asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:640
       native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
       arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
       acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline]
       acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:572
       acpi_idle_enter+0x352/0x4f0 drivers/acpi/processor_idle.c:709
       cpuidle_enter_state+0x516/0xf80 drivers/cpuidle/cpuidle.c:239
       cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:356
       call_cpuidle kernel/sched/idle.c:155 [inline]
       cpuidle_idle_call kernel/sched/idle.c:236 [inline]
       do_idle+0x3ce/0x680 kernel/sched/idle.c:303
       cpu_startup_entry+0x3d/0x60 kernel/sched/idle.c:401
       start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:281
       secondary_startup_64_no_verify+0xcf/0xdb

-> #2 (&tty->write_wait){-...}-{2:2}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
       __wake_up_common_lock kernel/sched/wait.c:137 [inline]
       __wake_up+0xfd/0x1c0 kernel/sched/wait.c:160
       tty_port_default_wakeup+0xa2/0xf0 drivers/tty/tty_port.c:71
       serial8250_tx_chars+0x60d/0x800 drivers/tty/serial/8250/8250_port.c:1860
       serial8250_handle_irq+0x4ff/0x6a0 drivers/tty/serial/8250/8250_port.c:1967
       serial8250_default_handle_irq+0xc8/0x1e0 drivers/tty/serial/8250/8250_port.c:1987
       serial8250_interrupt+0xa1/0x1e0 drivers/tty/serial/8250/8250_core.c:126
       __handle_irq_event_percpu+0x2a8/0xb20 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x85/0x1e0 kernel/irq/handle.c:210
       handle_edge_irq+0x245/0xbf0 kernel/irq/chip.c:819
       generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
       handle_irq arch/x86/kernel/irq.c:231 [inline]
       __common_interrupt+0xd7/0x1f0 arch/x86/kernel/irq.c:250
       common_interrupt+0x9f/0xc0 arch/x86/kernel/irq.c:240
       asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:640
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
       _raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:405 [inline]
       uart_write+0x6af/0x930 drivers/tty/serial/serial_core.c:600
       process_output_block drivers/tty/n_tty.c:586 [inline]
       n_tty_write+0xd7f/0x1260 drivers/tty/n_tty.c:2367
       do_tty_write drivers/tty/tty_io.c:1018 [inline]
       file_tty_write+0x504/0x890 drivers/tty/tty_io.c:1089
       call_write_iter include/linux/fs.h:2248 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x7ae/0xba0 fs/read_write.c:584
       ksys_write+0x19c/0x2c0 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #1 (&port_lock_key){-...}-{2:2}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
       serial8250_console_write+0x19d/0x1750 drivers/tty/serial/8250/8250_port.c:3410
       call_console_driver kernel/printk/printk.c:1942 [inline]
       console_emit_next_record+0xb09/0xea0 kernel/printk/printk.c:2742
       console_unlock+0x278/0x7c0 kernel/printk/printk.c:2871
       vprintk_emit+0x523/0x740 kernel/printk/printk.c:2268
       _printk+0xd1/0x111 kernel/printk/printk.c:2293
       register_console+0x69e/0x990 kernel/printk/printk.c:3219
       univ8250_console_init+0x41/0x43 drivers/tty/serial/8250/8250_core.c:687
       console_init+0x1d6/0x7f3 kernel/printk/printk.c:3309
       start_kernel+0x30b/0x53f init/main.c:1074
       secondary_startup_64_no_verify+0xcf/0xdb

-> #0 (console_owner){....}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       console_lock_spinning_enable kernel/printk/printk.c:1805 [inline]
       console_emit_next_record+0xa17/0xea0 kernel/printk/printk.c:2739
       console_unlock+0x278/0x7c0 kernel/printk/printk.c:2871
       vprintk_emit+0x523/0x740 kernel/printk/printk.c:2268
       _printk+0xd1/0x111 kernel/printk/printk.c:2293
       fail_dump lib/fault-inject.c:45 [inline]
       should_fail_ex+0x387/0x4d0 lib/fault-inject.c:147
       strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118
       strncpy_from_user_nofault+0x6c/0x130 mm/maccess.c:186
       bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:204 [inline]
       ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:213 [inline]
       bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:210
       bpf_prog_6fb7ada547f278f2+0x35/0x37
       bpf_dispatcher_nop_func include/linux/bpf.h:970 [inline]
       __bpf_prog_run include/linux/filter.h:600 [inline]
       bpf_prog_run include/linux/filter.h:607 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2275 [inline]
       bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2316
       trace_sched_switch include/trace/events/sched.h:222 [inline]
       __schedule+0x2116/0x4550 kernel/sched/core.c:6555
       preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6727
       preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6751
       preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
       vprintk_emit+0x683/0x740 kernel/printk/printk.c:2269
       _printk+0xd1/0x111 kernel/printk/printk.c:2293
       validate_nla lib/nlattr.c:391 [inline]
       __nla_validate_parse+0xdc3/0x2b70 lib/nlattr.c:603
       __nla_validate+0x3a/0x50 lib/nlattr.c:645
       nlmsg_validate_deprecated include/net/netlink.h:890 [inline]
       rtm_to_fib_config+0xab/0x1280 net/ipv4/fib_frontend.c:736
       inet_rtm_newroute+0xed/0x280 net/ipv4/fib_frontend.c:893
       rtnetlink_rcv_msg+0x818/0xff0 net/core/rtnetlink.c:6122
       netlink_rcv_skb+0x1cd/0x410 net/netlink/af_netlink.c:2508
       netlink_unicast_kernel net/netlink/af_netlink.c:1326 [inline]
       netlink_unicast+0x7d8/0x970 net/netlink/af_netlink.c:1352
       netlink_sendmsg+0xa26/0xd60 net/netlink/af_netlink.c:1874
       sock_sendmsg_nosec net/socket.c:716 [inline]
       __sock_sendmsg net/socket.c:728 [inline]
       ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2499
       ___sys_sendmsg net/socket.c:2553 [inline]
       __sys_sendmsg+0x2a9/0x390 net/socket.c:2582
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Chain exists of:
  console_owner --> &p->pi_lock --> &rq->__lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&rq->__lock);
                               lock(&p->pi_lock);
                               lock(&rq->__lock);
  lock(console_owner);

 *** DEADLOCK ***

4 locks held by syz-executor.4/3715:
 #0: ffffffff8e2946a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e2946a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6119
 #1: ffff8880b9939e18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
 #2: ffffffff8d12a1e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
 #2: ffffffff8d12a1e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
 #2: ffffffff8d12a1e0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2274 [inline]
 #2: ffffffff8d12a1e0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x16a/0x470 kernel/trace/bpf_trace.c:2316
 #3: ffffffff8d0063a0 (console_lock){+.+.}-{0:0}, at: _printk+0xd1/0x111 kernel/printk/printk.c:2293

stack backtrace:
CPU: 1 PID: 3715 Comm: syz-executor.4 Not tainted 6.1.67-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 console_lock_spinning_enable kernel/printk/printk.c:1805 [inline]
 console_emit_next_record+0xa17/0xea0 kernel/printk/printk.c:2739
 console_unlock+0x278/0x7c0 kernel/printk/printk.c:2871
 vprintk_emit+0x523/0x740 kernel/printk/printk.c:2268
 _printk+0xd1/0x111 kernel/printk/printk.c:2293
 fail_dump lib/fault-inject.c:45 [inline]
 should_fail_ex+0x387/0x4d0 lib/fault-inject.c:147
 strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x6c/0x130 mm/maccess.c:186
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:204 [inline]
 ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:213 [inline]
 bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:210
 bpf_prog_6fb7ada547f278f2+0x35/0x37
 bpf_dispatcher_nop_func include/linux/bpf.h:970 [inline]
 __bpf_prog_run include/linux/filter.h:600 [inline]
 bpf_prog_run include/linux/filter.h:607 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2275 [inline]
 bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2316
 trace_sched_switch include/trace/events/sched.h:222 [inline]
 __schedule+0x2116/0x4550 kernel/sched/core.c:6555
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6727
 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6751
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 vprintk_emit+0x683/0x740 kernel/printk/printk.c:2269
 _printk+0xd1/0x111 kernel/printk/printk.c:2293
 validate_nla lib/nlattr.c:391 [inline]
 __nla_validate_parse+0xdc3/0x2b70 lib/nlattr.c:603
 __nla_validate+0x3a/0x50 lib/nlattr.c:645
 nlmsg_validate_deprecated include/net/netlink.h:890 [inline]
 rtm_to_fib_config+0xab/0x1280 net/ipv4/fib_frontend.c:736
 inet_rtm_newroute+0xed/0x280 net/ipv4/fib_frontend.c:893
 rtnetlink_rcv_msg+0x818/0xff0 net/core/rtnetlink.c:6122
 netlink_rcv_skb+0x1cd/0x410 net/netlink/af_netlink.c:2508
 netlink_unicast_kernel net/netlink/af_netlink.c:1326 [inline]
 netlink_unicast+0x7d8/0x970 net/netlink/af_netlink.c:1352
 netlink_sendmsg+0xa26/0xd60 net/netlink/af_netlink.c:1874
 sock_sendmsg_nosec net/socket.c:716 [inline]
 __sock_sendmsg net/socket.c:728 [inline]
 ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2499
 ___sys_sendmsg net/socket.c:2553 [inline]
 __sys_sendmsg+0x2a9/0x390 net/socket.c:2582
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f672a07cba9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f67293fe0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f672a19bf80 RCX: 00007f672a07cba9
RDX: 0000000000000000 RSI: 0000000020000940 RDI: 0000000000000003
RBP: 00007f67293fe120 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 000000000000000b R14: 00007f672a19bf80 R15: 00007ffe0e3490a8
 </TASK>
CPU: 1 PID: 3715 Comm: syz-executor.4 Not tainted 6.1.67-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail_ex+0x3a6/0x4d0 lib/fault-inject.c:147
 strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x6c/0x130 mm/maccess.c:186
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:204 [inline]
 ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:213 [inline]
 bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:210
 bpf_prog_6fb7ada547f278f2+0x35/0x37
 bpf_dispatcher_nop_func include/linux/bpf.h:970 [inline]
 __bpf_prog_run include/linux/filter.h:600 [inline]
 bpf_prog_run include/linux/filter.h:607 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2275 [inline]
 bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2316
 trace_sched_switch include/trace/events/sched.h:222 [inline]
 __schedule+0x2116/0x4550 kernel/sched/core.c:6555
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6727
 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6751
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 vprintk_emit+0x683/0x740 kernel/printk/printk.c:2269
 _printk+0xd1/0x111 kernel/printk/printk.c:2293
 validate_nla lib/nlattr.c:391 [inline]
 __nla_validate_parse+0xdc3/0x2b70 lib/nlattr.c:603
 __nla_validate+0x3a/0x50 lib/nlattr.c:645
 nlmsg_validate_deprecated include/net/netlink.h:890 [inline]
 rtm_to_fib_config+0xab/0x1280 net/ipv4/fib_frontend.c:736
 inet_rtm_newroute+0xed/0x280 net/ipv4/fib_frontend.c:893
 rtnetlink_rcv_msg+0x818/0xff0 net/core/rtnetlink.c:6122
 netlink_rcv_skb+0x1cd/0x410 net/netlink/af_netlink.c:2508
 netlink_unicast_kernel net/netlink/af_netlink.c:1326 [inline]
 netlink_unicast+0x7d8/0x970 net/netlink/af_netlink.c:1352
 netlink_sendmsg+0xa26/0xd60 net/netlink/af_netlink.c:1874
 sock_sendmsg_nosec net/socket.c:716 [inline]
 __sock_sendmsg net/socket.c:728 [inline]
 ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2499
 ___sys_sendmsg net/socket.c:2553 [inline]
 __sys_sendmsg+0x2a9/0x390 net/socket.c:2582
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f672a07cba9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f67293fe0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f672a19bf80 RCX: 00007f672a07cba9
RDX: 0000000000000000 RSI: 0000000020000940 RDI: 0000000000000003
RBP: 00007f67293fe120 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 000000000000000b R14: 00007f672a19bf80 R15: 00007ffe0e3490a8
 </TASK>
netlink: 'syz-executor.4': attribute type 1 has an invalid length.