================================ WARNING: inconsistent lock state syzkaller #0 Not tainted -------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. syz.2.183/6776 [HC0[0]:SC0[0]:HE1:SE1] takes: ffff8880573e7ca8 (&p->tcfa_lock){+.?.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff8880573e7ca8 (&p->tcfa_lock){+.?.}-{3:3}, at: tcf_nat_init+0x50a/0x920 net/sched/act_nat.c:98 {IN-SOFTIRQ-W} state was registered at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] est_fetch_counters net/core/gen_estimator.c:67 [inline] est_timer+0xd4/0x9f0 net/core/gen_estimator.c:83 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 handle_softirqs+0x283/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 blkcg_maybe_throttle_current+0x4ce/0xb40 block/blk-cgroup.c:2043 resume_user_mode_work include/linux/resume_user_mode.h:60 [inline] exit_to_user_mode_loop+0xae/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f irq event stamp: 233 hardirqs last enabled at (233): [] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] hardirqs last enabled at (233): [] _raw_spin_unlock_irqrestore+0x85/0x110 kernel/locking/spinlock.c:194 hardirqs last disabled at (232): [] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] hardirqs last disabled at (232): [] _raw_spin_lock_irqsave+0x82/0xf0 kernel/locking/spinlock.c:162 softirqs last enabled at (206): [] local_bh_disable include/linux/bottom_half.h:20 [inline] softirqs last enabled at (206): [] rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] softirqs last enabled at (206): [] __dev_queue_xmit+0x27b/0x3b50 net/core/dev.c:4650 softirqs last disabled at (200): [] local_bh_disable include/linux/bottom_half.h:20 [inline] softirqs last disabled at (200): [] rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] softirqs last disabled at (200): [] __dev_queue_xmit+0x27b/0x3b50 net/core/dev.c:4650 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&p->tcfa_lock); lock(&p->tcfa_lock); *** DEADLOCK *** 1 lock held by syz.2.183/6776: #0: ffffffff8f538d48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f538d48 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x71c/0xb70 net/core/rtnetlink.c:6952 stack backtrace: CPU: 1 UID: 0 PID: 6776 Comm: syz.2.183 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_usage_bug+0x297/0x2e0 kernel/locking/lockdep.c:4042 valid_state+0xc3/0xf0 kernel/locking/lockdep.c:4056 mark_lock_irq+0x36/0x390 kernel/locking/lockdep.c:4267 mark_lock+0x11b/0x190 kernel/locking/lockdep.c:4753 mark_usage kernel/locking/lockdep.c:-1 [inline] __lock_acquire+0x9e2/0xd20 kernel/locking/lockdep.c:5191 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] tcf_nat_init+0x50a/0x920 net/sched/act_nat.c:98 tcf_action_init_1+0x460/0x6d0 net/sched/act_api.c:1431 tcf_action_init+0x2cf/0xab0 net/sched/act_api.c:1506 tcf_action_add net/sched/act_api.c:2100 [inline] tc_ctl_action+0x430/0xbd0 net/sched/act_api.c:2157 rtnetlink_rcv_msg+0x779/0xb70 net/core/rtnetlink.c:6955 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2614 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668 __sys_sendmsg net/socket.c:2700 [inline] __do_sys_sendmsg net/socket.c:2705 [inline] __se_sys_sendmsg net/socket.c:2703 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe34df8ebe9 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:00007fe34eed4038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fe34e1c5fa0 RCX: 00007fe34df8ebe9 RDX: 0000000000000980 RSI: 00002000000002c0 RDI: 0000000000000004 RBP: 00007fe34e011e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe34e1c6038 R14: 00007fe34e1c5fa0 R15: 00007ffcca72f088