CVE-2024-35973

CVE Details

Release Date:

2024-05-20

Description

In the Linux kernel, the following vulnerability has been resolved:\ngeneve: fix header validation in geneve[6]_xmit_skb\nsyzbot is able to trigger an uninit-value in geneve_xmit() [1]\nProblem : While most ip tunnel helpers (like ip_tunnel_get_dsfield())\nuses skb_protocol(skb, true), pskb_inet_may_pull() is only using\nskb->protocol.\nIf anything else than ETH_P_IPV6 or ETH_P_IP is found in skb->protocol,\npskb_inet_may_pull() does nothing at all.\nIf a vlan tag was provided by the caller (af_packet in the syzbot case),\nthe network header might not point to the correct location, and skb\nlinear part could be smaller than expected.\nAdd skb_vlan_inet_prepare() to perform a complete mac validation.\nUse this in geneve for the moment, I suspect we need to adopt this\nmore broadly.\nv4 - Jakub reported v3 broke l2_tos_ttl_inherit.sh selftest\n- Only call __vlan_get_protocol() for vlan types.\nv2,v3 - Addressed Sabrina comments on v1 and v2\n[1]\nBUG: KMSAN: uninit-value in geneve_xmit_skb drivers/net/geneve.c:910 [inline]\nBUG: KMSAN: uninit-value in geneve_xmit+0x302d/0x5420 drivers/net/geneve.c:1030\ngeneve_xmit_skb drivers/net/geneve.c:910 [inline]\ngeneve_xmit+0x302d/0x5420 drivers/net/geneve.c:1030\n__netdev_start_xmit include/linux/netdevice.h:4903 [inline]\nnetdev_start_xmit include/linux/netdevice.h:4917 [inline]\nxmit_one net/core/dev.c:3531 [inline]\ndev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3547\n__dev_queue_xmit+0x348d/0x52c0 net/core/dev.c:4335\ndev_queue_xmit include/linux/netdevice.h:3091 [inline]\npacket_xmit+0x9c/0x6c0 net/packet/af_packet.c:276\npacket_snd net/packet/af_packet.c:3081 [inline]\npacket_sendmsg+0x8bb0/0x9ef0 net/packet/af_packet.c:3113\nsock_sendmsg_nosec net/socket.c:730 [inline]\n__sock_sendmsg+0x30f/0x380 net/socket.c:745\n__sys_sendto+0x685/0x830 net/socket.c:2191\n__do_sys_sendto net/socket.c:2203 [inline]\n__se_sys_sendto net/socket.c:2199 [inline]\n__x64_sys_sendto+0x125/0x1d0 net/socket.c:2199\ndo_syscall_64+0xd5/0x1f0\nentry_SYSCALL_64_after_hwframe+0x6d/0x75\nUninit was created at:\nslab_post_alloc_hook mm/slub.c:3804 [inline]\nslab_alloc_node mm/slub.c:3845 [inline]\nkmem_cache_alloc_node+0x613/0xc50 mm/slub.c:3888\nkmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:577\n__alloc_skb+0x35b/0x7a0 net/core/skbuff.c:668\nalloc_skb include/linux/skbuff.h:1318 [inline]\nalloc_skb_with_frags+0xc8/0xbf0 net/core/skbuff.c:6504\nsock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2795\npacket_alloc_skb net/packet/af_packet.c:2930 [inline]\npacket_snd net/packet/af_packet.c:3024 [inline]\npacket_sendmsg+0x722d/0x9ef0 net/packet/af_packet.c:3113\nsock_sendmsg_nosec net/socket.c:730 [inline]\n__sock_sendmsg+0x30f/0x380 net/socket.c:745\n__sys_sendto+0x685/0x830 net/socket.c:2191\n__do_sys_sendto net/socket.c:2203 [inline]\n__se_sys_sendto net/socket.c:2199 [inline]\n__x64_sys_sendto+0x125/0x1d0 net/socket.c:2199\ndo_syscall_64+0xd5/0x1f0\nentry_SYSCALL_64_after_hwframe+0x6d/0x75\nCPU: 0 PID: 5033 Comm: syz-executor346 Not tainted 6.9.0-rc1-syzkaller-00005-g928a87efa423 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024

See more information about CVE-2024-35973 from MITRE CVE dictionary and NIST NVD

CVSS Scoring

NOTE: The following CVSS v3.1 metrics and score provided are preliminary and subject to review.

Base Score:	5.5	CVSS Vector:	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector:	Local network	Attack Complexity:	Low
Privileges Required:	Low	User Interaction:	None
Scope:	Unchanged	Confidentiality Impact:	None
Integrity Impact:	None	Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 9 (kernel)	ELSA-2024-9315	2024-11-14