CVE-2022-49691

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

erspan: do not assume transport header is always set

Rewrite tests in ip6erspantunnelxmit() and erspanfbxmit() to not assume transport header is set.

syzbot reported:

WARNING: CPU: 0 PID: 1350 at include/linux/skbuff.h:2911 skbtransportheader include/linux/skbuff.h:2911 [inline] WARNING: CPU: 0 PID: 1350 at include/linux/skbuff.h:2911 ip6erspantunnelxmit+0x15af/0x2eb0 net/ipv6/ip6gre.c:963 Modules linked in: CPU: 0 PID: 1350 Comm: aoetx0 Not tainted 5.19.0-rc2-syzkaller-00160-g274295c6e53f #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 RIP: 0010:skbtransportheader include/linux/skbuff.h:2911 [inline] RIP: 0010:ip6erspantunnelxmit+0x15af/0x2eb0 net/ipv6/ip6_gre.c:963 Code: 0f 47 f0 40 88 b5 7f fe ff ff e8 8c 16 4b f9 89 de bf ff ff ff ff e8 a0 12 4b f9 66 83 fb ff 0f 85 1d f1 ff ff e8 71 16 4b f9 <0f> 0b e9 43 f0 ff ff e8 65 16 4b f9 48 8d 85 30 ff ff ff ba 60 00 RSP: 0018:ffffc90005daf910 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 000000000000ffff RCX: 0000000000000000 RDX: ffff88801f032100 RSI: ffffffff882e8d3f RDI: 0000000000000003 RBP: ffffc90005dafab8 R08: 0000000000000003 R09: 000000000000ffff R10: 000000000000ffff R11: 0000000000000000 R12: ffff888024f21d40 R13: 000000000000a288 R14: 00000000000000b0 R15: ffff888025a2e000 FS: 0000000000000000(0000) GS:ffff88802c800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e425000 CR3: 000000006d099000 CR4: 0000000000152ef0 Call Trace: <TASK> __netdevstartxmit include/linux/netdevice.h:4805 [inline] netdevstartxmit include/linux/netdevice.h:4819 [inline] xmitone net/core/dev.c:3588 [inline] devhardstartxmit+0x188/0x880 net/core/dev.c:3604 schdirectxmit+0x19f/0xbe0 net/sched/sch_generic.c:342 __devxmitskb net/core/dev.c:3815 [inline] _devqueuexmit+0x14a1/0x3900 net/core/dev.c:4219 devqueuexmit include/linux/netdevice.h:2994 [inline] tx+0x6a/0xc0 drivers/block/aoe/aoenet.c:63 kthread+0x1e7/0x3b0 drivers/block/aoe/aoecmd.c:1229 kthread+0x2e9/0x3a0 kernel/kthread.c:376 retfromfork+0x1f/0x30 arch/x86/entry/entry64.S:302 </TASK>