--- id: CVE-2024-35973 title: |- In the Linux kernel, the following vulnerability has been resolved: geneve: fix header validation in geneve[6]_xmit_skb syzbot is able to trigger an uninit-value in geneve_xmit() [1] Problem : While most ip tunnel helpers (like ip_tun… summary: |- In the Linux kernel, the following vulnerability has been resolved: geneve: fix header validation in geneve[6]_xmit_skb syzbot is able to trigger an uninit-value in geneve_xmit() [1] Problem : While most ip tunnel helpers (like ip_tun… severity: medium cvss: 5.5 cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H' cwe: - CWE-908 vendor: linux product: linux_kernel affected: - 'linux_kernel >= 4.19.191, < 4.19.313' - 'linux_kernel >= 5.4.119, < 5.4.275' - 'linux_kernel >= 5.10.37, < 5.10.216' - 'linux_kernel >= 5.11.21, < 5.12' - 'linux_kernel >= 5.12.4, < 5.15.156' - 'linux_kernel >= 5.16, < 6.1.87' - 'linux_kernel >= 6.2, < 6.6.28' - 'linux_kernel >= 6.7, < 6.8.7' - linux_kernel = 6.9 - debian_linux = 10.0 patched: - linux_kernel 6.8.7 published: '2024-05-20' updated: '2026-10-15' sourceUpdated: '2026-10-15T01:18:15.077' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2024-35973' references: - url: 'https://git.kernel.org/stable/c/10204df9beda4978bd1d0c2db0d8375bfb03b915' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/190d9efa5773f26d6f334b1b8be282c4fa13fd5e' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/357163fff3a6e48fe74745425a32071ec9caf852' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/3c1ae6de74e3d2d6333d29a2d3e13e6094596c79' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/43be590456e1f3566054ce78ae2dbb68cbe1a536' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/4a1b65d1e55d53b397cb27014208be1e04172670' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/d3adf11d7993518a39bd02b383cfe657ccc0023c' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/d8a6213d70accb403b82924a1c229e733433a5ef' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/10204df9beda4978bd1d0c2db0d8375bfb03b915' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/190d9efa5773f26d6f334b1b8be282c4fa13fd5e' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/357163fff3a6e48fe74745425a32071ec9caf852' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/3c1ae6de74e3d2d6333d29a2d3e13e6094596c79' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/43be590456e1f3566054ce78ae2dbb68cbe1a536' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/4a1b65d1e55d53b397cb27014208be1e04172670' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/d3adf11d7993518a39bd02b383cfe657ccc0023c' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://git.kernel.org/stable/c/d8a6213d70accb403b82924a1c229e733433a5ef' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://cert-portal.siemens.com/productcert/html/ssa-265688.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e - url: 'https://cert-portal.siemens.com/productcert/html/ssa-613116.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e tags: - nvd - cve.org epss: 0.00252 epssPercentile: 0.16575 ingestedAt: '2026-10-15T03:30:12.694Z' ssvc: exploitation: none automatable: 'no' technicalImpact: partial timestamp: '2024-05-29T18:16:33.435108Z' --- ## Overview In the Linux kernel, the following vulnerability has been resolved: geneve: fix header validation in geneve[6]_xmit_skb syzbot is able to trigger an uninit-value in geneve_xmit() [1] Problem : While most ip tunnel helpers (like ip_tunnel_get_dsfield()) uses skb_protocol(skb, true), pskb_inet_may_pull() is only using skb->protocol. If anything else than ETH_P_IPV6 or ETH_P_IP is found in skb->protocol, pskb_inet_may_pull() does nothing at all. If a vlan tag was provided by the caller (af_packet in the syzbot case), the network header might not point to the correct location, and skb linear part could be smaller than expected. Add skb_vlan_inet_prepare() to perform a complete mac validation. Use this in geneve for the moment, I suspect we need to adopt this more broadly. v4 - Jakub reported v3 broke l2_tos_ttl_inherit.sh selftest - Only call __vlan_get_protocol() for vlan types. v2,v3 - Addressed Sabrina comments on v1 and v2 [1] BUG: KMSAN: uninit-value in geneve_xmit_skb drivers/net/geneve.c:910 [inline] BUG: KMSAN: uninit-value in geneve_xmit+0x302d/0x5420 drivers/net/geneve.c:1030 geneve_xmit_skb drivers/net/geneve.c:910 [inline] geneve_xmit+0x302d/0x5420 drivers/net/geneve.c:1030 __netdev_start_xmit include/linux/netdevice.h:4903 [inline] netdev_start_xmit include/linux/netdevice.h:4917 [inline] xmit_one net/core/dev.c:3531 [inline] dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3547 __dev_queue_xmit+0x348d/0x52c0 net/core/dev.c:4335 dev_queue_xmit include/linux/netdevice.h:3091 [inline] packet_xmit+0x9c/0x6c0 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3081 [inline] packet_sendmsg+0x8bb0/0x9ef0 net/packet/af_packet.c:3113 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x30f/0x380 net/socket.c:745 __sys_sendto+0x685/0x830 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0x125/0x1d0 net/socket.c:2199 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Uninit was created at: slab_post_alloc_hook mm/slub.c:3804 [inline] slab_alloc_node mm/slub.c:3845 [inline] kmem_cache_alloc_node+0x613/0xc50 mm/slub.c:3888 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:577 __alloc_skb+0x35b/0x7a0 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1318 [inline] alloc_skb_with_frags+0xc8/0xbf0 net/core/skbuff.c:6504 sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2795 packet_alloc_skb net/packet/af_packet.c:2930 [inline] packet_snd net/packet/af_packet.c:3024 [inline] packet_sendmsg+0x722d/0x9ef0 net/packet/af_packet.c:3113 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x30f/0x380 net/socket.c:745 __sys_sendto+0x685/0x830 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0x125/0x1d0 net/socket.c:2199 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 CPU: 0 PID: 5033 Comm: syz-executor346 Not tainted 6.9.0-rc1-syzkaller-00005-g928a87efa423 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 ## Affected - `linux_kernel >= 4.19.191, < 4.19.313` - `linux_kernel >= 5.4.119, < 5.4.275` - `linux_kernel >= 5.10.37, < 5.10.216` - `linux_kernel >= 5.11.21, < 5.12` - `linux_kernel >= 5.12.4, < 5.15.156` - `linux_kernel >= 5.16, < 6.1.87` - `linux_kernel >= 6.2, < 6.6.28` - `linux_kernel >= 6.7, < 6.8.7` - `linux_kernel = 6.9` - `debian_linux = 10.0` ## Remediation Upgrade past the affected range: - `linux_kernel 6.8.7`