CVE-2023-53053

In the Linux kernel, the following vulnerability has been resolved:

erspan: do not use skbmacheader() in ndostartxmit()

Drivers should not assume skbmacheader(skb) == skb->data in their ndostartxmit().

Use skbnetworkoffset() and skbtransportoffset() which better describe what is needed in erspanfbxmit() and ip6erspantunnelxmit()

syzbot reported: WARNING: CPU: 0 PID: 5083 at include/linux/skbuff.h:2873 skbmacheader include/linux/skbuff.h:2873 [inline] WARNING: CPU: 0 PID: 5083 at include/linux/skbuff.h:2873 ip6erspantunnelxmit+0x1d9c/0x2d90 net/ipv6/ip6gre.c:962 Modules linked in: CPU: 0 PID: 5083 Comm: syz-executor406 Not tainted 6.3.0-rc2-syzkaller-00866-gd4671cb96fa3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 RIP: 0010:skbmacheader include/linux/skbuff.h:2873 [inline] RIP: 0010:ip6erspantunnelxmit+0x1d9c/0x2d90 net/ipv6/ip6gre.c:962 Code: 04 02 41 01 de 84 c0 74 08 3c 03 0f 8e 1c 0a 00 00 45 89 b4 24 c8 00 00 00 c6 85 77 fe ff ff 01 e9 33 e7 ff ff e8 b4 27 a1 f8 <0f> 0b e9 b6 e7 ff ff e8 a8 27 a1 f8 49 8d bf f0 0c 00 00 48 b8 00 RSP: 0018:ffffc90003b2f830 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 000000000000ffff RCX: 0000000000000000 RDX: ffff888021273a80 RSI: ffffffff88e1bd4c RDI: 0000000000000003 RBP: ffffc90003b2f9d8 R08: 0000000000000003 R09: 000000000000ffff R10: 000000000000ffff R11: 0000000000000000 R12: ffff88802b28da00 R13: 00000000000000d0 R14: ffff88807e25b6d0 R15: ffff888023408000 FS: 0000555556a61300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055e5b11eb6e8 CR3: 0000000027c1b000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> _netdevstartxmit include/linux/netdevice.h:4900 [inline] netdevstartxmit include/linux/netdevice.h:4914 [inline] _devdirectxmit+0x504/0x730 net/core/dev.c:4300 devdirectxmit include/linux/netdevice.h:3088 [inline] packetxmit+0x20a/0x390 net/packet/afpacket.c:285 packetsnd net/packet/afpacket.c:3075 [inline] packetsendmsg+0x31a0/0x5150 net/packet/afpacket.c:3107 socksendmsgnosec net/socket.c:724 [inline] socksendmsg+0xde/0x190 net/socket.c:747 _syssendto+0x23a/0x340 net/socket.c:2142 _dosyssendto net/socket.c:2154 [inline] _sesyssendto net/socket.c:2150 [inline] _x64syssendto+0xe1/0x1b0 net/socket.c:2150 dosyscallx64 arch/x86/entry/common.c:50 [inline] dosyscall64+0x39/0xb0 arch/x86/entry/common.c:80 entrySYSCALL64afterhwframe+0x63/0xcd RIP: 0033:0x7f123aaa1039 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 90 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc15d12058 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f123aaa1039 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000020000040 R09: 0000000000000014 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f123aa648c0 R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000