Linux Kernel up to 5.10.128/5.15.52/5.18.9 include/linux/skbuff.h skb_tunnel_check_pmtu privilege escalation

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.10.128/5.15.52/5.18.9. It has been rated as problematic. Affected by this issue is the function skb_tunnel_check_pmtu in the library include/linux/skbuff.h. This manipulation causes an unknown weakness. The identification of this vulnerability is CVE-2022-49663. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as problematic was found in Linux Kernel up to 5.10.128/5.15.52/5.18.9. Affected by this vulnerability is the function skb_tunnel_check_pmtu in the library include/linux/skbuff.h. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: tunnels: do not assume mac header is set in skb_tunnel_check_pmtu() Recently added debug in commit f9aefd6b2aa3 ("net: warn if mac header was not set") caught a bug in skb_tunnel_check_pmtu(), as shown in this syzbot report [1]. In ndo_start_xmit() paths, there is really no need to use skb->mac_header, because skb->data is supposed to point at it. [1] WARNING: CPU: 1 PID: 8604 at include/linux/skbuff.h:2784 skb_mac_header_len include/linux/skbuff.h:2784 [inline] WARNING: CPU: 1 PID: 8604 at include/linux/skbuff.h:2784 skb_tunnel_check_pmtu+0x5de/0x2f90 net/ipv4/ip_tunnel_core.c:413 Modules linked in: CPU: 1 PID: 8604 Comm: syz-executor.3 Not tainted 5.19.0-rc2-syzkaller-00443-g8720bd951b8e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:skb_mac_header_len include/linux/skbuff.h:2784 [inline] RIP: 0010:skb_tunnel_check_pmtu+0x5de/0x2f90 net/ipv4/ip_tunnel_core.c:413 Code: 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 80 3c 02 00 0f 84 b9 fe ff ff 4c 89 ff e8 7c 0f d7 f9 e9 ac fe ff ff e8 c2 13 8a f9 0b e9 28 fc ff ff e8 b6 13 8a f9 48 8b 54 24 70 48 b8 00 00 00 RSP: 0018:ffffc90002e4f520 EFLAGS: 00010212 RAX: 0000000000000324 RBX: ffff88804d5fd500 RCX: ffffc90005b52000 RDX: 0000000000040000 RSI: ffffffff87f05e3e RDI: 0000000000000003 RBP: ffffc90002e4f650 R08: 0000000000000003 R09: 000000000000ffff R10: 000000000000ffff R11: 0000000000000000 R12: 000000000000ffff R13: 0000000000000000 R14: 000000000000ffcd R15: 000000000000001f FS: 00007f3babba9700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000080 CR3: 0000000075319000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: geneve_xmit_skb drivers/net/geneve.c:927 [inline] geneve_xmit+0xcf8/0x35d0 drivers/net/geneve.c:1107 __netdev_start_xmit include/linux/netdevice.h:4805 [inline] netdev_start_xmit include/linux/netdevice.h:4819 [inline] __dev_direct_xmit+0x500/0x730 net/core/dev.c:4309 dev_direct_xmit include/linux/netdevice.h:3007 [inline] packet_direct_xmit+0x1b8/0x2c0 net/packet/af_packet.c:282 packet_snd net/packet/af_packet.c:3073 [inline] packet_sendmsg+0x21f4/0x55d0 net/packet/af_packet.c:3104 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 ____sys_sendmsg+0x6eb/0x810 net/socket.c:2489 ___sys_sendmsg+0xf3/0x170 net/socket.c:2543 __sys_sendmsg net/socket.c:2572 [inline] __do_sys_sendmsg net/socket.c:2581 [inline] __se_sys_sendmsg net/socket.c:2579 [inline] __x64_sys_sendmsg+0x132/0x220 net/socket.c:2579 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f3baaa89109 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3babba9168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f3baab9bf60 RCX: 00007f3baaa89109 RDX: 0000000000000000 RSI: 0000000020000a00 RDI: 0000000000000003 RBP: 00007f3baaae305d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe74f2543f R14: 00007f3babba9300 R15: 0000000000022000

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2022-49663 since 02/26/2025. The exploitation appears to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 241018 (EulerOS 2.0 SP13 : kernel (EulerOS-SA-2025-1704)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.129, 5.15.53 or 5.18.10 eliminates this vulnerability. Applying the patch 59c51c3b545128a92ebfb6dbae990d3abee110e7/674a641e5b67e16ba3112eacd680ff87b38539de/32dcf62efa0003f92a976aea0c57f118e689de8b/853a7614880231747040cada91d2b8d2e995c51a 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 (241018). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.128
• 5.15.0
• 5.15.1
• 5.15.2
• 5.15.3
• 5.15.4
• 5.15.5
• 5.15.6
• 5.15.7
• 5.15.8
• 5.15.9
• 5.15.10
• 5.15.11
• 5.15.12
• 5.15.13
• 5.15.14
• 5.15.15
• 5.15.16
• 5.15.17
• 5.15.18
• 5.15.19
• 5.15.20
• 5.15.21
• 5.15.22
• 5.15.23
• 5.15.24
• 5.15.25
• 5.15.26
• 5.15.27
• 5.15.28
• 5.15.29
• 5.15.30
• 5.15.31
• 5.15.32
• 5.15.33
• 5.15.34
• 5.15.35
• 5.15.36
• 5.15.37
• 5.15.38
• 5.15.39
• 5.15.40
• 5.15.41
• 5.15.42
• 5.15.43
• 5.15.44
• 5.15.45
• 5.15.46
• 5.15.47
• 5.15.48
• 5.15.49
• 5.15.50
• 5.15.51
• 5.15.52
• 5.18.0
• 5.18.1
• 5.18.2
• 5.18.3
• 5.18.4
• 5.18.5
• 5.18.6
• 5.18.7
• 5.18.8
• 5.18.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

Discussion