FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.7.18245/25817 is trying to acquire lock:
ffffffff8c311180 (console_owner){-.-.}-{0:0}, at: console_lock_spinning_enable+0x2c/0x60 kernel/printk/printk.c:1802

but task is already holding lock:
ffff8880b913a358 (&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:4485
       copy_process+0x22f6/0x3e20 kernel/fork.c:2395
       kernel_clone+0x23f/0x990 kernel/fork.c:2679
       kernel_thread+0xfa/0x160 kernel/fork.c:2731
       rest_init+0x21/0x330 init/main.c:720
       start_kernel+0x489/0x540 init/main.c:1154
       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+0xb0/0x100 kernel/locking/spinlock.c:162
       try_to_wake_up+0x5c/0x1050 kernel/sched/core.c:4049
       __wake_up_common+0x2a4/0x4e0 kernel/sched/wait.c:108
       __wake_up_common_lock kernel/sched/wait.c:138 [inline]
       __wake_up+0x10e/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+0x299/0x9d0 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
       __sanitizer_cov_trace_pc+0x58/0x60 kernel/kcov.c:214
       vma_compute_subtree_gap mm/mmap.c:316 [inline]
       browse_rb mm/mmap.c:357 [inline]
       validate_mm+0x461/0x950 mm/mmap.c:423
       remove_vma_list mm/mmap.c:2631 [inline]
       __do_munmap+0xcf3/0xdf0 mm/mmap.c:2902
       do_munmap mm/mmap.c:2910 [inline]
       munmap_vma_range mm/mmap.c:603 [inline]
       __mmap_region mm/mmap.c:1757 [inline]
       mmap_region+0x8b4/0x1650 mm/mmap.c:2933
       do_mmap+0x819/0xe90 mm/mmap.c:1586
       vm_mmap_pgoff+0x1c1/0x2d0 mm/util.c:551
       ksys_mmap_pgoff+0x54b/0x790 mm/mmap.c:1635
       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

-> #2 (&tty->write_wait){-...}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162
       __wake_up_common_lock kernel/sched/wait.c:137 [inline]
       __wake_up+0xf4/0x180 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+0x299/0x9d0 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+0xbc/0x120 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:419 [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+0xd2e/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:2173 [inline]
       new_sync_write fs/read_write.c:507 [inline]
       vfs_write+0x745/0xd60 fs/read_write.c:594
       ksys_write+0x152/0x260 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+0xb0/0x100 kernel/locking/spinlock.c:162
       serial8250_console_write+0x178/0x1000 drivers/tty/serial/8250/8250_port.c:3362
       call_console_drivers kernel/printk/printk.c:-1 [inline]
       console_unlock+0xb9a/0x1120 kernel/printk/printk.c:2744
       vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
       _printk+0xda/0x130 kernel/printk/printk.c:2299
       register_console+0x699/0x980 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+0x2fc/0x540 init/main.c:1090
       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+0x2c42/0x7d10 kernel/locking/lockdep.c:5012
       lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
       console_lock_spinning_enable+0x51/0x60 kernel/printk/printk.c:1805
       console_unlock+0x8b6/0x1120 kernel/printk/printk.c:2741
       vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
       _printk+0xda/0x130 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_9bca56546c9b26d5+0x3d/0xb24
       bpf_dispatcher_nop_func include/linux/bpf.h:888 [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+0x19e/0x350 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+0x1d9e/0x43c0 kernel/sched/core.c:6392
       preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
       irqentry_exit+0x63/0x70 kernel/entry/common.c:432
       asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
       lock_sock_nested+0x0/0x100
       lock_sock include/net/sock.h:1744 [inline]
       netlink_insert+0xc0/0x11f0 net/netlink/af_netlink.c:557
       netlink_autobind+0x1f3/0x2b0 net/netlink/af_netlink.c:829
       netlink_sendmsg+0x51d/0xbe0 net/netlink/af_netlink.c:1881
       sock_sendmsg_nosec net/socket.c:706 [inline]
       __sock_sendmsg net/socket.c:718 [inline]
       ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445
       ___sys_sendmsg+0x236/0x2e0 net/socket.c:2499
       __sys_sendmsg net/socket.c:2528 [inline]
       __do_sys_sendmsg net/socket.c:2537 [inline]
       __se_sys_sendmsg+0x1af/0x290 net/socket.c:2535
       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.7.18245/25817:
 #0: ffff8880b913a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
 #1: ffffffff8c31c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:312
 #2: ffffffff8c311260 (console_lock){+.+.}-{0:0}, at: vprintk_emit+0xa7/0x150 kernel/printk/printk.c:2273

stack backtrace:
CPU: 1 PID: 25817 Comm: syz.7.18245 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 check_noncircular+0x296/0x330 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+0x2c42/0x7d10 kernel/locking/lockdep.c:5012
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 console_lock_spinning_enable+0x51/0x60 kernel/printk/printk.c:1805
 console_unlock+0x8b6/0x1120 kernel/printk/printk.c:2741
 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
 _printk+0xda/0x130 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_9bca56546c9b26d5+0x3d/0xb24
 bpf_dispatcher_nop_func include/linux/bpf.h:888 [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+0x19e/0x350 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+0x1d9e/0x43c0 kernel/sched/core.c:6392
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_sock_nested+0x0/0x100 net/core/sock.c:3257
Code: f7 48 89 de 5b 41 5c 41 5d 41 5e 41 5f e9 38 eb ff ff 44 89 f9 80 e1 07 80 c1 03 38 c1 7c 8a 4c 89 ff e8 73 c2 e3 f9 eb 80 90 <55> 41 57 41 56 41 55 41 54 53 89 f5 49 89 fe 49 bc 00 00 00 00 00
RSP: 0018:ffffc90002e9f7d8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff888020072000 RCX: ffff88807dee1dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888020072000
RBP: ffffc90002e9f910 R08: ffffffff8d8967af R09: 1ffffffff1b12cf5
R10: dffffc0000000000 R11: fffffbfff1b12cf6 R12: dffffc0000000000
R13: ffff888020072000 R14: ffff888066ac9a80 R15: ffff88814005c000
 lock_sock include/net/sock.h:1744 [inline]
 netlink_insert+0xc0/0x11f0 net/netlink/af_netlink.c:557
 netlink_autobind+0x1f3/0x2b0 net/netlink/af_netlink.c:829
 netlink_sendmsg+0x51d/0xbe0 net/netlink/af_netlink.c:1881
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2499
 __sys_sendmsg net/socket.c:2528 [inline]
 __do_sys_sendmsg net/socket.c:2537 [inline]
 __se_sys_sendmsg+0x1af/0x290 net/socket.c:2535
 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: 0033:0x7ff746316cb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff744572028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff746591fa0 RCX: 00007ff746316cb9
RDX: 0000000000000000 RSI: 0000200000000600 RDI: 0000000000000008
RBP: 00007ff744572090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ff746592038 R14: 00007ff746591fa0 R15: 00007ffe14ad9868
 </TASK>
CPU: 1 PID: 25817 Comm: syz.7.18245 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 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_9bca56546c9b26d5+0x3d/0xb24
 bpf_dispatcher_nop_func include/linux/bpf.h:888 [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+0x19e/0x350 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+0x1d9e/0x43c0 kernel/sched/core.c:6392
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_sock_nested+0x0/0x100 net/core/sock.c:3257
Code: f7 48 89 de 5b 41 5c 41 5d 41 5e 41 5f e9 38 eb ff ff 44 89 f9 80 e1 07 80 c1 03 38 c1 7c 8a 4c 89 ff e8 73 c2 e3 f9 eb 80 90 <55> 41 57 41 56 41 55 41 54 53 89 f5 49 89 fe 49 bc 00 00 00 00 00
RSP: 0018:ffffc90002e9f7d8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff888020072000 RCX: ffff88807dee1dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888020072000
RBP: ffffc90002e9f910 R08: ffffffff8d8967af R09: 1ffffffff1b12cf5
R10: dffffc0000000000 R11: fffffbfff1b12cf6 R12: dffffc0000000000
R13: ffff888020072000 R14: ffff888066ac9a80 R15: ffff88814005c000
 lock_sock include/net/sock.h:1744 [inline]
 netlink_insert+0xc0/0x11f0 net/netlink/af_netlink.c:557
 netlink_autobind+0x1f3/0x2b0 net/netlink/af_netlink.c:829
 netlink_sendmsg+0x51d/0xbe0 net/netlink/af_netlink.c:1881
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2499
 __sys_sendmsg net/socket.c:2528 [inline]
 __do_sys_sendmsg net/socket.c:2537 [inline]
 __se_sys_sendmsg+0x1af/0x290 net/socket.c:2535
 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: 0033:0x7ff746316cb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff744572028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff746591fa0 RCX: 00007ff746316cb9
RDX: 0000000000000000 RSI: 0000200000000600 RDI: 0000000000000008
RBP: 00007ff744572090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ff746592038 R14: 00007ff746591fa0 R15: 00007ffe14ad9868
 </TASK>
netlink: 'syz.7.18245': attribute type 39 has an invalid length.
----------------
Code disassembly (best guess):
   0:	f7 48 89 de 5b 41 5c 	testl  $0x5c415bde,-0x77(%rax)
   7:	41 5d                	pop    %r13
   9:	41 5e                	pop    %r14
   b:	41 5f                	pop    %r15
   d:	e9 38 eb ff ff       	jmp    0xffffeb4a
  12:	44 89 f9             	mov    %r15d,%ecx
  15:	80 e1 07             	and    $0x7,%cl
  18:	80 c1 03             	add    $0x3,%cl
  1b:	38 c1                	cmp    %al,%cl
  1d:	7c 8a                	jl     0xffffffa9
  1f:	4c 89 ff             	mov    %r15,%rdi
  22:	e8 73 c2 e3 f9       	call   0xf9e3c29a
  27:	eb 80                	jmp    0xffffffa9
  29:	90                   	nop
* 2a:	55                   	push   %rbp <-- trapping instruction
  2b:	41 57                	push   %r15
  2d:	41 56                	push   %r14
  2f:	41 55                	push   %r13
  31:	41 54                	push   %r12
  33:	53                   	push   %rbx
  34:	89 f5                	mov    %esi,%ebp
  36:	49 89 fe             	mov    %rdi,%r14
  39:	49                   	rex.WB
  3a:	bc 00 00 00 00       	mov    $0x0,%esp