netlink: 'syz.1.2988': attribute type 29 has an invalid length.
netlink: 'syz.1.2988': attribute type 29 has an invalid length.
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
======================================================
WARNING: possible circular locking dependency detected
5.15.183-syzkaller #0 Not tainted
------------------------------------------------------
syz.1.2988/12063 is trying to acquire lock:
ffffffff8c1108e0 (console_owner){-.-.}-{0:0}, at: console_trylock_spinning+0x150/0x350 kernel/printk/printk.c:1879

but task is already holding lock:
ffff8880b903a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&rq->__lock){-.-.}-{2:2}:
       _raw_spin_lock_nested+0x2e/0x40 kernel/locking/spinlock.c:368
       raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
       raw_spin_rq_lock kernel/sched/sched.h:1326 [inline]
       rq_lock kernel/sched/sched.h:1621 [inline]
       task_fork_fair+0x5c/0x350 kernel/sched/fair.c:11499
       sched_cgroup_fork+0x2c6/0x320 kernel/sched/core.c:4466
       copy_process+0x22bd/0x3e60 kernel/fork.c:2319
       kernel_clone+0x219/0x930 kernel/fork.c:2603
       kernel_thread+0xc8/0x120 kernel/fork.c:2655
       rest_init+0x21/0x330 init/main.c:706
       start_kernel+0x486/0x530 init/main.c:1140
       secondary_startup_64_no_verify+0xb1/0xbb

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
       try_to_wake_up+0x5c/0x1050 kernel/sched/core.c:4030
       __wake_up_common+0x2a4/0x4e0 kernel/sched/wait.c:108
       __wake_up_common_lock kernel/sched/wait.c:138 [inline]
       __wake_up+0x108/0x180 kernel/sched/wait.c:157
       tty_port_default_wakeup+0xa5/0xf0 drivers/tty/tty_port.c:51
       serial8250_tx_chars+0x629/0x830 drivers/tty/serial/8250/8250_port.c:1828
       serial8250_handle_irq+0x519/0x610 drivers/tty/serial/8250/8250_port.c:1924
       serial8250_default_handle_irq+0xb4/0x1a0 drivers/tty/serial/8250/8250_port.c:1941
       serial8250_interrupt+0x9b/0x1c0 drivers/tty/serial/8250/8250_core.c:127
       __handle_irq_event_percpu+0x291/0x9b0 kernel/irq/handle.c:156
       handle_irq_event_percpu kernel/irq/handle.c:196 [inline]
       handle_irq_event+0xa5/0x220 kernel/irq/handle.c:213
       handle_edge_irq+0x243/0xb20 kernel/irq/chip.c:819
       generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
       handle_irq arch/x86/kernel/irq.c:233 [inline]
       __common_interrupt+0xd7/0x1e0 arch/x86/kernel/irq.c:252
       common_interrupt+0xb0/0xd0 arch/x86/kernel/irq.c:242
       asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667
       native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
       arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
       default_idle+0xb/0x10 arch/x86/kernel/process.c:722
       default_idle_call+0x81/0xc0 kernel/sched/idle.c:112
       cpuidle_idle_call kernel/sched/idle.c:194 [inline]
       do_idle+0x21b/0x5b0 kernel/sched/idle.c:306
       cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403
       start_kernel+0x486/0x530 init/main.c:1140
       secondary_startup_64_no_verify+0xb1/0xbb

-> #2 (&tty->write_wait){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
       __wake_up_common_lock kernel/sched/wait.c:137 [inline]
       __wake_up+0xed/0x180 kernel/sched/wait.c:157
       tty_port_default_wakeup+0xa5/0xf0 drivers/tty/tty_port.c:51
       serial8250_tx_chars+0x629/0x830 drivers/tty/serial/8250/8250_port.c:1828
       serial8250_handle_irq+0x519/0x610 drivers/tty/serial/8250/8250_port.c:1924
       serial8250_default_handle_irq+0xb4/0x1a0 drivers/tty/serial/8250/8250_port.c:1941
       serial8250_interrupt+0x9b/0x1c0 drivers/tty/serial/8250/8250_core.c:127
       __handle_irq_event_percpu+0x291/0x9b0 kernel/irq/handle.c:156
       handle_irq_event_percpu kernel/irq/handle.c:196 [inline]
       handle_irq_event+0xa5/0x220 kernel/irq/handle.c:213
       handle_edge_irq+0x243/0xb20 kernel/irq/chip.c:819
       generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
       handle_irq arch/x86/kernel/irq.c:233 [inline]
       __common_interrupt+0xd7/0x1e0 arch/x86/kernel/irq.c:252
       common_interrupt+0xb0/0xd0 arch/x86/kernel/irq.c:242
       asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
       _raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:418 [inline]
       uart_write+0x62f/0x880 drivers/tty/serial/serial_core.c:592
       process_output_block drivers/tty/n_tty.c:592 [inline]
       n_tty_write+0xd21/0x1210 drivers/tty/n_tty.c:2339
       do_tty_write drivers/tty/tty_io.c:1038 [inline]
       file_tty_write+0x557/0x910 drivers/tty/tty_io.c:1110
       call_write_iter include/linux/fs.h:2172 [inline]
       new_sync_write fs/read_write.c:507 [inline]
       vfs_write+0x712/0xd00 fs/read_write.c:594
       ksys_write+0x14d/0x250 fs/read_write.c:647
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #1 (&port_lock_key){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
       serial8250_console_write+0x170/0xf80 drivers/tty/serial/8250/8250_port.c:3363
       call_console_drivers kernel/printk/printk.c:-1 [inline]
       console_unlock+0xc86/0x1200 kernel/printk/printk.c:2744
       vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
       _printk+0xcc/0x110 kernel/printk/printk.c:2299
       register_console+0x682/0x960 kernel/printk/printk.c:3107
       univ8250_console_init+0x41/0x50 drivers/tty/serial/8250/8250_core.c:690
       console_init+0x177/0x5d0 kernel/printk/printk.c:3207
       start_kernel+0x2f9/0x530 init/main.c:1076
       secondary_startup_64_no_verify+0xb1/0xbb

-> #0 (console_owner){-.-.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
       lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
       console_trylock_spinning+0x170/0x350 kernel/printk/printk.c:1896
       vprintk_emit+0xa7/0x150 kernel/printk/printk.c:2273
       _printk+0xcc/0x110 kernel/printk/printk.c:2299
       fail_dump lib/fault-inject.c:45 [inline]
       should_fail+0x36d/0x4c0 lib/fault-inject.c:146
       strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118
       strncpy_from_user_nofault+0x6d/0x140 mm/maccess.c:295
       bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:194 [inline]
       ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:300 [inline]
       bpf_probe_read_compat_str+0xdd/0x170 kernel/trace/bpf_trace.c:296
       bpf_prog_c1796171ffc7efef+0x35/0xd18
       bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline]
       __bpf_prog_run include/linux/filter.h:628 [inline]
       bpf_prog_run include/linux/filter.h:635 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline]
       bpf_trace_run3+0x17e/0x320 kernel/trace/bpf_trace.c:1916
       __traceiter_sched_switch+0x83/0xb0 include/trace/events/sched.h:220
       trace_sched_switch include/trace/events/sched.h:220 [inline]
       __schedule+0x1d8b/0x43b0 kernel/sched/core.c:6373
       schedule+0x11b/0x1e0 kernel/sched/core.c:6459
       schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518
       mutex_optimistic_spin+0x295/0x300 kernel/locking/mutex.c:503
       __mutex_lock_common+0x210/0x2390 kernel/locking/mutex.c:599
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       netlink_dump+0xca/0xcb0 net/netlink/af_netlink.c:2212
       netlink_recvmsg+0x653/0xdb0 net/netlink/af_netlink.c:1988
       ____sys_recvmsg+0x291/0x580 net/socket.c:-1
       ___sys_recvmsg+0x1af/0x4f0 net/socket.c:2697
       __sys_recvmsg net/socket.c:2727 [inline]
       __do_sys_recvmsg net/socket.c:2737 [inline]
       __se_sys_recvmsg net/socket.c:2734 [inline]
       __x64_sys_recvmsg+0x1dd/0x2a0 net/socket.c:2734
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

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 ***

3 locks held by syz.1.2988/12063:
 #0: ffffffff8d22a388 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0xca/0xcb0 net/netlink/af_netlink.c:2212
 #1: ffff8880b903a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
 #2: ffffffff8c11bea0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311

stack backtrace:
CPU: 0 PID: 12063 Comm: syz.1.2988 Not tainted 5.15.183-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 console_trylock_spinning+0x170/0x350 kernel/printk/printk.c:1896
 vprintk_emit+0xa7/0x150 kernel/printk/printk.c:2273
 _printk+0xcc/0x110 kernel/printk/printk.c:2299
 fail_dump lib/fault-inject.c:45 [inline]
 should_fail+0x36d/0x4c0 lib/fault-inject.c:146
 strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x6d/0x140 mm/maccess.c:295
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:194 [inline]
 ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:300 [inline]
 bpf_probe_read_compat_str+0xdd/0x170 kernel/trace/bpf_trace.c:296
 bpf_prog_c1796171ffc7efef+0x35/0xd18
 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline]
 bpf_trace_run3+0x17e/0x320 kernel/trace/bpf_trace.c:1916
 __traceiter_sched_switch+0x83/0xb0 include/trace/events/sched.h:220
 trace_sched_switch include/trace/events/sched.h:220 [inline]
 __schedule+0x1d8b/0x43b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518
 mutex_optimistic_spin+0x295/0x300 kernel/locking/mutex.c:503
 __mutex_lock_common+0x210/0x2390 kernel/locking/mutex.c:599
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 netlink_dump+0xca/0xcb0 net/netlink/af_netlink.c:2212
 netlink_recvmsg+0x653/0xdb0 net/netlink/af_netlink.c:1988
 ____sys_recvmsg+0x291/0x580 net/socket.c:-1
 ___sys_recvmsg+0x1af/0x4f0 net/socket.c:2697
 __sys_recvmsg net/socket.c:2727 [inline]
 __do_sys_recvmsg net/socket.c:2737 [inline]
 __se_sys_recvmsg net/socket.c:2734 [inline]
 __x64_sys_recvmsg+0x1dd/0x2a0 net/socket.c:2734
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f8557a83969
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:00007f85558eb038 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00007f8557caafa0 RCX: 00007f8557a83969
RDX: 0000000000000000 RSI: 0000200000000900 RDI: 0000000000000003
RBP: 00007f85558eb090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 00007f8557caafa0 R15: 00007ffc59d21bc8
 </TASK>
CPU: 0 PID: 12063 Comm: syz.1.2988 Not tainted 5.15.183-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail+0x38c/0x4c0 lib/fault-inject.c:146
 strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x6d/0x140 mm/maccess.c:295
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:194 [inline]
 ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:300 [inline]
 bpf_probe_read_compat_str+0xdd/0x170 kernel/trace/bpf_trace.c:296
 bpf_prog_c1796171ffc7efef+0x35/0xd18
 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline]
 bpf_trace_run3+0x17e/0x320 kernel/trace/bpf_trace.c:1916
 __traceiter_sched_switch+0x83/0xb0 include/trace/events/sched.h:220
 trace_sched_switch include/trace/events/sched.h:220 [inline]
 __schedule+0x1d8b/0x43b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518
 mutex_optimistic_spin+0x295/0x300 kernel/locking/mutex.c:503
 __mutex_lock_common+0x210/0x2390 kernel/locking/mutex.c:599
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 netlink_dump+0xca/0xcb0 net/netlink/af_netlink.c:2212
 netlink_recvmsg+0x653/0xdb0 net/netlink/af_netlink.c:1988
 ____sys_recvmsg+0x291/0x580 net/socket.c:-1
 ___sys_recvmsg+0x1af/0x4f0 net/socket.c:2697
 __sys_recvmsg net/socket.c:2727 [inline]
 __do_sys_recvmsg net/socket.c:2737 [inline]
 __se_sys_recvmsg net/socket.c:2734 [inline]
 __x64_sys_recvmsg+0x1dd/0x2a0 net/socket.c:2734
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f8557a83969
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:00007f85558eb038 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00007f8557caafa0 RCX: 00007f8557a83969
RDX: 0000000000000000 RSI: 0000200000000900 RDI: 0000000000000003
RBP: 00007f85558eb090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 00007f8557caafa0 R15: 00007ffc59d21bc8
 </TASK>
netlink: 'syz.1.2988': attribute type 29 has an invalid length.