------------[ cut here ]------------ memcpy: detected field-spanning write (size 40) of single field "&top_iph->saddr" at net/ipv6/ah6.c:439 (size 16) WARNING: net/ipv6/ah6.c:439 at ah6_output+0xece/0x1510 net/ipv6/ah6.c:439, CPU#1: syz-executor270/5835 Modules linked in: CPU: 1 UID: 0 PID: 5835 Comm: syz-executor270 Not tainted 6.16.0-rc3-next-20250626-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:ah6_output+0xece/0x1510 net/ipv6/ah6.c:439 Code: ff e8 66 29 82 f7 c6 05 60 e1 6e 05 01 90 b9 10 00 00 00 48 c7 c7 80 a1 a2 8c 4c 89 f6 48 c7 c2 e0 a3 a2 8c e8 e3 db 45 f7 90 <0f> 0b 90 90 e9 ab fe ff ff e8 d4 20 38 01 48 8b 4c 24 28 80 e1 07 RSP: 0018:ffffc90003f370a0 EFLAGS: 00010246 RAX: 26d747fa118b3400 RBX: ffff8880267e5808 RCX: ffff88807a09bc00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002 RBP: ffffc90003f37230 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff1c3a428 R12: dffffc0000000000 R13: 1ffff920007e6e34 R14: 0000000000000028 R15: 0000000000000030 FS: 000055558e4e6380(0000) GS:ffff888125ae6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000045ad50 CR3: 0000000075b5e000 CR4: 00000000003526f0 Call Trace: xfrm_output_one net/xfrm/xfrm_output.c:555 [inline] xfrm_output_resume+0x2c55/0x6170 net/xfrm/xfrm_output.c:590 __xfrm6_output+0x2eb/0x1070 net/ipv6/xfrm6_output.c:103 NF_HOOK_COND include/linux/netfilter.h:306 [inline] xfrm6_output+0x1c6/0x4f0 net/ipv6/xfrm6_output.c:108 ip6_send_skb+0x1d5/0x390 net/ipv6/ip6_output.c:1982 l2tp_ip6_sendmsg+0x12f2/0x17c0 net/l2tp/l2tp_ip6.c:661 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x19c/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: 0033:0x7f96a7340669 Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcb1680d88 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007ffcb1680f58 RCX: 00007f96a7340669 RDX: 0000000000000800 RSI: 0000200000000540 RDI: 0000000000000005 RBP: 00007f96a73b3610 R08: 00007ffcb1680f58 R09: 00007ffcb1680f58 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffcb1680f48 R14: 0000000000000001 R15: 0000000000000001