{"id":"DEBIAN-CVE-2024-35973","details":"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-\u003eprotocol.  If anything else than ETH_P_IPV6 or ETH_P_IP is found in skb-\u003eprotocol, 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","modified":"2026-09-15T09:03:14.041692003Z","published":"2024-05-20T10:15:12.077Z","upstream":["CVE-2024-35973"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2024-35973"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.90-1"}]}],"versions":["6.1.27-1","6.1.37-1","6.1.38-1","6.1.38-2","6.1.38-2~bpo11+1","6.1.38-3","6.1.38-4","6.1.38-4~bpo11+1","6.1.52-1","6.1.55-1","6.1.55-1~bpo11+1","6.1.64-1","6.1.66-1","6.1.67-1","6.1.69-1","6.1.69-1~bpo11+1","6.1.76-1","6.1.76-1~bpo11+1","6.1.82-1","6.1.85-1","6.1.90-1~bpo11+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2024-35973.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.8.9-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2024-35973.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.8.9-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2024-35973.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}