TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 12009 Comm: syz-executor.4 Not tainted 4.19.205-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:em_u32_match+0x156/0x300 net/sched/em_u32.c:33 Code: 9c 01 00 00 41 23 5c 24 0c 48 63 db 4c 01 fb e8 30 ff c2 fa 49 8d 7c 24 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 21 RSP: 0018:ffff8880618c6e48 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff88809636cd10 RCX: ffffc9000e647000 RDX: 0000000000000001 RSI: ffffffff869f9390 RDI: 0000000000000008 RBP: ffff8880a53278c0 R08: 0000000000000000 R09: 0000000000000002 R10: 0000000000000004 R11: 0000000000074071 R12: 0000000000000000 R13: 0000000000000000 R14: ffff88809636cd00 R15: dffffc0000000000 FS: 00007f11f1d81700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4f73fff718 CR3: 00000000664c8000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tcf_em_match net/sched/ematch.c:496 [inline] __tcf_em_tree_match+0x14a/0x530 net/sched/ematch.c:522 tcf_em_tree_match include/net/pkt_cls.h:531 [inline] basic_classify+0x1c0/0x2b0 net/sched/cls_basic.c:49 tcf_classify+0x120/0x3c0 net/sched/cls_api.c:979 hfsc_classify net/sched/sch_hfsc.c:1141 [inline] hfsc_enqueue+0x31a/0x10a0 net/sched/sch_hfsc.c:1545 __dev_xmit_skb net/core/dev.c:3494 [inline] __dev_queue_xmit+0x140a/0x2e00 net/core/dev.c:3807 hfsplus: unable to find HFS+ superblock neigh_resolve_output+0x55a/0x910 net/core/neighbour.c:1374 neigh_output include/net/neighbour.h:501 [inline] ip_finish_output2+0xd76/0x15a0 net/ipv4/ip_output.c:230 ip_do_fragment+0x1e1a/0x2620 net/ipv4/ip_output.c:680 ip_fragment.constprop.0+0x174/0x240 net/ipv4/ip_output.c:551 ip_finish_output+0xa35/0x10b0 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip_mc_output+0x268/0xec0 net/ipv4/ip_output.c:391 dst_output include/net/dst.h:455 [inline] ip_local_out+0xaf/0x170 net/ipv4/ip_output.c:125 ip_send_skb net/ipv4/ip_output.c:1451 [inline] ip_push_pending_frames+0x8b/0x140 net/ipv4/ip_output.c:1471 raw_sendmsg+0x1e9d/0x29e0 net/ipv4/raw.c:677 inet_sendmsg+0x132/0x5a0 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:661 sock_no_sendpage+0xf5/0x140 net/core/sock.c:2668 inet_sendpage+0x465/0x650 net/ipv4/af_inet.c:816 kernel_sendpage net/socket.c:3581 [inline] sock_sendpage+0xdf/0x140 net/socket.c:912 pipe_to_sendpage+0x268/0x330 fs/splice.c:452 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x389/0x800 fs/splice.c:627 splice_from_pipe fs/splice.c:662 [inline] generic_splice_sendpage+0xd4/0x140 fs/splice.c:833 do_splice_from fs/splice.c:852 [inline] do_splice fs/splice.c:1154 [inline] __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice+0xfe7/0x16d0 fs/splice.c:1408 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4665f9 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f11f1d81188 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665f9 RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00000000004bfcc4 R08: 0000000000019403 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038 R13: 00007ffc1369e29f R14: 00007f11f1d81300 R15: 0000000000022000 Modules linked in: ---[ end trace c7533c8ec228fb52 ]--- RIP: 0010:em_u32_match+0x156/0x300 net/sched/em_u32.c:33 Code: 9c 01 00 00 41 23 5c 24 0c 48 63 db 4c 01 fb e8 30 ff c2 fa 49 8d 7c 24 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 21 RSP: 0018:ffff8880618c6e48 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff88809636cd10 RCX: ffffc9000e647000 RDX: 0000000000000001 RSI: ffffffff869f9390 RDI: 0000000000000008 RBP: ffff8880a53278c0 R08: 0000000000000000 R09: 0000000000000002 R10: 0000000000000004 R11: 0000000000074071 R12: 0000000000000000 R13: 0000000000000000 R14: ffff88809636cd00 R15: dffffc0000000000 FS: 00007f11f1d81700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4f73fff718 CR3: 00000000664c8000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 9c pushfq 1: 01 00 add %eax,(%rax) 3: 00 41 23 add %al,0x23(%rcx) 6: 5c pop %rsp 7: 24 0c and $0xc,%al 9: 48 63 db movslq %ebx,%rbx c: 4c 01 fb add %r15,%rbx f: e8 30 ff c2 fa callq 0xfac2ff44 14: 49 8d 7c 24 08 lea 0x8(%r12),%rdi 19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 20: fc ff df 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx <-- trapping instruction 2e: 48 89 f8 mov %rdi,%rax 31: 83 e0 07 and $0x7,%eax 34: 83 c0 03 add $0x3,%eax 37: 38 d0 cmp %dl,%al 39: 7c 08 jl 0x43 3b: 84 d2 test %dl,%dl 3d: 0f .byte 0xf 3e: 85 21 test %esp,(%rcx)