BUG: please report to dccp@vger.kernel.org => prev = 5, last = 5 at net/dccp/ccids/lib/packet_history.c:414/tfrc_rx_hist_sample_rtt() CPU: 1 PID: 969 Comm: kworker/u4:1 Not tainted 6.7.0-rc4-syzkaller-00039-g9ace34a8e446 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x125/0x1b0 lib/dump_stack.c:106 tfrc_rx_hist_sample_rtt+0x3dd/0x4a0 net/dccp/ccids/lib/packet_history.c:414 ccid3_hc_rx_packet_recv+0x443/0xf50 net/dccp/ccids/ccid3.c:760 ccid_hc_rx_packet_recv net/dccp/ccid.h:182 [inline] dccp_deliver_input_to_ccids+0xe3/0x260 net/dccp/input.c:176 dccp_rcv_established net/dccp/input.c:374 [inline] dccp_rcv_established+0x106/0x160 net/dccp/input.c:364 dccp_v4_do_rcv+0x169/0x1b0 net/dccp/ipv4.c:675 sk_backlog_rcv include/net/sock.h:1121 [inline] __sk_receive_skb+0x2af/0x840 net/core/sock.c:571 dccp_v4_rcv+0x128a/0x1980 net/dccp/ipv4.c:898 ip_protocol_deliver_rcu+0x9f/0x480 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2e4/0x510 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:461 [inline] ip_rcv_finish+0x1c4/0x2f0 net/ipv4/ip_input.c:449 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_rcv+0xaf/0xd0 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core+0x115/0x180 net/core/dev.c:5529 __netif_receive_skb+0x1f/0x1b0 net/core/dev.c:5643 process_backlog+0x101/0x6b0 net/core/dev.c:5971 __napi_poll.constprop.0+0xb4/0x540 net/core/dev.c:6533 napi_poll net/core/dev.c:6602 [inline] net_rx_action+0x956/0xe90 net/core/dev.c:6735 __do_softirq+0x21a/0x8de kernel/softirq.c:553 invoke_softirq kernel/softirq.c:427 [inline] __irq_exit_rcu kernel/softirq.c:632 [inline] irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644 sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:lock_acquire+0x1ef/0x520 kernel/locking/lockdep.c:5722 Code: c1 05 dd 6c 9a 7e 83 f8 01 0f 85 b4 02 00 00 9c 58 f6 c4 02 0f 85 9f 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc900069bfa30 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff92000d37f48 RCX: 00000000cd35dc42 RDX: 0000000000000001 RSI: ffffffff8accbc20 RDI: ffffffff8b2f0ea0 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff23e35d1 R10: ffffffff91f1ae8f R11: 0000000000000001 R12: 0000000000000001 R13: 0000000000000001 R14: ffffffff8d9123f8 R15: 0000000000000000 __raw_spin_trylock include/linux/spinlock_api_smp.h:90 [inline] _raw_spin_trylock+0x5f/0x70 kernel/locking/spinlock.c:138 spin_trylock include/linux/spinlock.h:361 [inline] aa_get_buffer+0x262/0x740 security/apparmor/lsm.c:1831 apparmor_bprm_creds_for_exec+0x5c3/0x2340 security/apparmor/domain.c:909 security_bprm_creds_for_exec+0x62/0xa0 security/security.c:1060 bprm_execve fs/exec.c:1850 [inline] bprm_execve+0x558/0x1a90 fs/exec.c:1810 kernel_execve+0x3d8/0x4e0 fs/exec.c:2022 call_usermodehelper_exec_async+0x256/0x4c0 kernel/umh.c:110 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 ---------------- Code disassembly (best guess): 0: c1 05 dd 6c 9a 7e 83 roll $0x83,0x7e9a6cdd(%rip) # 0x7e9a6ce4 7: f8 clc 8: 01 0f add %ecx,(%rdi) a: 85 b4 02 00 00 9c 58 test %esi,0x589c0000(%rdx,%rax,1) 11: f6 c4 02 test $0x2,%ah 14: 0f 85 9f 02 00 00 jne 0x2b9 1a: 48 85 ed test %rbp,%rbp 1d: 74 01 je 0x20 1f: fb sti 20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 27: fc ff df * 2a: 48 01 c3 add %rax,%rbx <-- trapping instruction 2d: 48 c7 03 00 00 00 00 movq $0x0,(%rbx) 34: 48 c7 43 08 00 00 00 movq $0x0,0x8(%rbx) 3b: 00 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 84 .byte 0x84 3f: 24 .byte 0x24