------------[ cut here ]------------ DEBUG_LOCKS_WARN_ON(1) WARNING: kernel/locking/lockdep.c:238 at hlock_class kernel/locking/lockdep.c:238 [inline], CPU#1: syz.6.6816/30871 WARNING: kernel/locking/lockdep.c:238 at hlock_class kernel/locking/lockdep.c:227 [inline], CPU#1: syz.6.6816/30871 WARNING: kernel/locking/lockdep.c:238 at check_wait_context kernel/locking/lockdep.c:4854 [inline], CPU#1: syz.6.6816/30871 WARNING: kernel/locking/lockdep.c:238 at __lock_acquire+0x13df/0x1a40 kernel/locking/lockdep.c:5187, CPU#1: syz.6.6816/30871 Modules linked in: CPU: 1 UID: 0 PID: 30871 Comm: syz.6.6816 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:hlock_class kernel/locking/lockdep.c:238 [inline] RIP: 0010:hlock_class kernel/locking/lockdep.c:227 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4854 [inline] RIP: 0010:__lock_acquire+0x13e6/0x1a40 kernel/locking/lockdep.c:5187 Code: 48 c7 c6 f4 4d 19 8e 67 48 0f b9 3a 44 8b 44 24 48 44 0f b6 4c 24 08 e9 d9 fb ff ff 48 8d 3d b1 34 3f 0f 48 c7 c6 f4 4d 19 8e <67> 48 0f b9 3a 44 8b 44 24 08 e9 e6 fb ff ff e8 66 86 34 03 89 c3 RSP: 0018:ffffc90000a08a78 EFLAGS: 00010046 RAX: 0000000000000001 RBX: ffff88807b585670 RCX: ffffffff81e845c2 RDX: ffff88807b584a80 RSI: ffffffff8e194df4 RDI: ffffffff91253280 RBP: ffff88807b584a80 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000001093 R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fd8700fb6c0(0000) GS:ffff888123eec000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000027459000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158 spin_lock include/linux/spinlock.h:342 [inline] tcp_tsq_handler+0x1d/0x200 net/ipv4/tcp_output.c:1291 tcp_tsq_workfn+0x2b2/0x560 net/ipv4/tcp_output.c:1325 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] bh_worker+0x646/0x890 kernel/workqueue.c:3708 workqueue_softirq_action+0x142/0x1a0 kernel/workqueue.c:3736 tasklet_action+0x14/0x70 kernel/softirq.c:965 handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x162/0x210 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:tcp_wfree+0x3d8/0x5c0 net/ipv4/tcp_output.c:1425 Code: e8 cd a4 e0 f7 4d 85 e4 75 75 e8 23 aa e0 f7 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 b1 a4 e0 f7 48 85 db 0f 85 19 01 00 00 03 aa e0 f7 48 b8 00 00 00 00 00 fc ff df 49 c7 44 05 00 00 00 RSP: 0018:ffffc90006fd6f70 EFLAGS: 00000287 RAX: 0000000000019edb RBX: 0000000000000000 RCX: ffffc90015050000 RDX: 0000000000080000 RSI: ffffffff8a29c9f7 RDI: ffff88807b584a80 RBP: ffff888044bbe800 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000200 R13: 1ffff92000dfadf1 R14: ffff8880b8539a68 R15: ffff888044bbf298 skb_release_head_state+0xbb/0x400 net/core/skbuff.c:1175 skb_release_all net/core/skbuff.c:1195 [inline] __kfree_skb net/core/skbuff.c:1211 [inline] sk_skb_reason_drop+0xc4/0x1b0 net/core/skbuff.c:1250 kfree_skb_reason include/linux/skbuff.h:1323 [inline] kfree_skb include/linux/skbuff.h:1332 [inline] __rtnl_unlock+0x97/0xf0 net/core/rtnetlink.c:148 netdev_run_todo+0x2e1/0x1600 net/core/dev.c:11714 rtnl_unlock net/core/rtnetlink.c:157 [inline] rtnl_nets_unlock net/core/rtnetlink.c:354 [inline] rtnl_setlink+0x671/0xae0 net/core/rtnetlink.c:3549 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:7076 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] sock_write_iter+0x53a/0x5b0 net/socket.c:1241 do_iter_readv_writev+0x6f7/0x930 fs/read_write.c:828 vfs_writev+0x360/0xdd0 fs/read_write.c:1058 do_writev+0x28a/0x340 fs/read_write.c:1104 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd86f19e0d9 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:00007fd8700fb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007fd86f425fa0 RCX: 00007fd86f19e0d9 RDX: 0000000000000001 RSI: 00002000000003c0 RDI: 0000000000000005 RBP: 00007fd86f235024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd86f426038 R14: 00007fd86f425fa0 R15: 00007ffe0c9bbe18 ---------------- Code disassembly (best guess): 0: 48 c7 c6 f4 4d 19 8e mov $0xffffffff8e194df4,%rsi 7: 67 48 0f b9 3a ud1 (%edx),%rdi c: 44 8b 44 24 48 mov 0x48(%rsp),%r8d 11: 44 0f b6 4c 24 08 movzbl 0x8(%rsp),%r9d 17: e9 d9 fb ff ff jmp 0xfffffbf5 1c: 48 8d 3d b1 34 3f 0f lea 0xf3f34b1(%rip),%rdi # 0xf3f34d4 23: 48 c7 c6 f4 4d 19 8e mov $0xffffffff8e194df4,%rsi * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: 44 8b 44 24 08 mov 0x8(%rsp),%r8d 34: e9 e6 fb ff ff jmp 0xfffffc1f 39: e8 66 86 34 03 call 0x33486a4 3e: 89 c3 mov %eax,%ebx