CVE-2024-56636

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> geneve: do not assume mac header is set in geneve_xmit_skb()<br /> <br /> We should not assume mac header is set in output path.<br /> <br /> Use skb_eth_hdr() instead of eth_hdr() to fix the issue.<br /> <br /> sysbot reported the following :<br /> <br /> WARNING: CPU: 0 PID: 11635 at include/linux/skbuff.h:3052 skb_mac_header include/linux/skbuff.h:3052 [inline]<br /> WARNING: CPU: 0 PID: 11635 at include/linux/skbuff.h:3052 eth_hdr include/linux/if_ether.h:24 [inline]<br /> WARNING: CPU: 0 PID: 11635 at include/linux/skbuff.h:3052 geneve_xmit_skb drivers/net/geneve.c:898 [inline]<br /> WARNING: CPU: 0 PID: 11635 at include/linux/skbuff.h:3052 geneve_xmit+0x4c38/0x5730 drivers/net/geneve.c:1039<br /> Modules linked in:<br /> CPU: 0 UID: 0 PID: 11635 Comm: syz.4.1423 Not tainted 6.12.0-syzkaller-10296-gaaf20f870da0 #0<br /> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024<br /> RIP: 0010:skb_mac_header include/linux/skbuff.h:3052 [inline]<br /> RIP: 0010:eth_hdr include/linux/if_ether.h:24 [inline]<br /> RIP: 0010:geneve_xmit_skb drivers/net/geneve.c:898 [inline]<br /> RIP: 0010:geneve_xmit+0x4c38/0x5730 drivers/net/geneve.c:1039<br /> 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 0b 90 e9 41 e4 ff ff e8 7b 48 4c fb 90 0f 0b 90 e9 cd e7 ff ff<br /> RSP: 0018:ffffc90003b2f870 EFLAGS: 00010283<br /> RAX: 000000000000037a RBX: 000000000000ffff RCX: ffffc9000dc3d000<br /> RDX: 0000000000080000 RSI: ffffffff86428417 RDI: 0000000000000003<br /> RBP: ffffc90003b2f9f0 R08: 0000000000000003 R09: 000000000000ffff<br /> R10: 000000000000ffff R11: 0000000000000002 R12: ffff88806603c000<br /> R13: 0000000000000000 R14: ffff8880685b2780 R15: 0000000000000e23<br /> FS: 00007fdc2deed6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000<br /> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033<br /> CR2: 0000001b30a1dff8 CR3: 0000000056b8c000 CR4: 00000000003526f0<br /> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000<br /> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400<br /> Call Trace:<br /> <br /> __netdev_start_xmit include/linux/netdevice.h:5002 [inline]<br /> netdev_start_xmit include/linux/netdevice.h:5011 [inline]<br /> __dev_direct_xmit+0x58a/0x720 net/core/dev.c:4490<br /> dev_direct_xmit include/linux/netdevice.h:3181 [inline]<br /> packet_xmit+0x1e4/0x360 net/packet/af_packet.c:285<br /> packet_snd net/packet/af_packet.c:3146 [inline]<br /> packet_sendmsg+0x2700/0x5660 net/packet/af_packet.c:3178<br /> sock_sendmsg_nosec net/socket.c:711 [inline]<br /> __sock_sendmsg net/socket.c:726 [inline]<br /> __sys_sendto+0x488/0x4f0 net/socket.c:2197<br /> __do_sys_sendto net/socket.c:2204 [inline]<br /> __se_sys_sendto net/socket.c:2200 [inline]<br /> __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2200<br /> do_syscall_x64 arch/x86/entry/common.c:52 [inline]<br /> do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83<br /> entry_SYSCALL_64_after_hwframe+0x77/0x7f