Linux Kernel up to 6.8.6 Header Validation l2_tos_ttl_inherit.sh geneve_xmit privilege escalation

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5.4$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.8.6. It has been declared as problematic. This issue affects the function geneve_xmit of the file l2_tos_ttl_inherit.sh of the component Header Validation Handler. The manipulation results in an unknown weakness. This vulnerability is identified as CVE-2024-35973. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.8.6. It has been classified as problematic. Affected is the function geneve_xmit of the file l2_tos_ttl_inherit.sh of the component Header Validation Handler. The impact remains unknown. CVE summarizes:

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

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2024-35973 since 05/17/2024. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 209785 (EulerOS Virtualization 2.12.0 : kernel (EulerOS-SA-2024-2781)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.19.313, 5.4.275, 5.10.216, 5.13, 5.15.156, 6.1.87, 6.6.28 or 6.8.7 eliminates this vulnerability. Applying the patch 43be590456e1/d3adf11d7993/10204df9beda/3c1ae6de74e3/4a1b65d1e55d/190d9efa5773/357163fff3a6/d8a6213d70ac is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (209785). Once again VulDB remains the best source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.4

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔍
VulDB Reliability: 🔍

CNA Base Score: 5.5
CNA Vector: 🔍

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 209785
Nessus Name: EulerOS Virtualization 2.12.0 : kernel (EulerOS-SA-2024-2781)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 4.19.313/5.4.275/5.10.216/5.13/5.15.156/6.1.87/6.6.28/6.8.7
Patch: 43be590456e1/d3adf11d7993/10204df9beda/3c1ae6de74e3/4a1b65d1e55d/190d9efa5773/357163fff3a6/d8a6213d70ac

Timelineinfo

05/17/2024 🔍
05/20/2024 +3 days 🔍
05/20/2024 +0 days 🔍
10/30/2024 +163 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2024-35973 (🔍)
GCVE (CVE): GCVE-0-2024-35973
GCVE (VulDB): GCVE-100-265236

Entryinfo

Created: 05/20/2024 12:32
Updated: 10/30/2024 03:50
Changes: 05/20/2024 12:32 (57), 10/29/2024 09:06 (2), 10/30/2024 03:50 (11)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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