Affected: Linux

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

geneve: do not assume mac header is set in geneve_xmit_skb()

We should not assume mac header is set in output path.

Use skb_eth_hdr() instead of eth_hdr() to fix the issue.

sysbot reported the following :

WARNING: CPU: 0 PID: 11635 at include/linux/skbuff.h:3052 skb_mac_header include/linux/skbuff.h:3052 [inline] WARNING: CPU: 0 PID: 11635 at include/linux/skbuff.h:3052 eth_hdr include/linux/if_ether.h:24 [inline] WARNING: CPU: 0 PID: 11635 at include/linux/skbuff.h:3052 geneve_xmit_skb drivers/net/geneve.c:898 [inline] WARNING: CPU: 0 PID: 11635 at include/linux/skbuff.h:3052 geneve_xmit+0x4c38/0x5730 drivers/net/geneve.c:1039 Modules linked in: CPU: 0 UID: 0 PID: 11635 Comm: syz.4.1423 Not tainted 6.12.0-syzkaller-10296-gaaf20f870da0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:skb_mac_header include/linux/skbuff.h:3052 [inline] RIP: 0010:eth_hdr include/linux/if_ether.h:24 [inline] RIP: 0010:geneve_xmit_skb drivers/net/geneve.c:898 [inline] RIP: 0010:geneve_xmit+0x4c38/0x5730 drivers/net/geneve.c:1039 Code: 21 c6 02 e9 35 d4 ff ff e8 a5 48 4c fb 90 0f 0b 90 e9 fd f5 ff ff e8 97 48 4c fb 90 0f 0b 90 e9 d8 f5 ff ff e8 89 48 4c fb 90 <0f> 0b 90 e9 41 e4 ff ff e8 7b 48 4c fb 90 0f 0b 90 e9 cd e7 ff ff RSP: 0018:ffffc90003b2f870 EFLAGS: 00010283 RAX: 000000000000037a RBX: 000000000000ffff RCX: ffffc9000dc3d000 RDX: 0000000000080000 RSI: fff…