CVE-2024-41091: tun: add missing verification for short frame
A denial-of-service (DoS) attack was found in the mlx5 driver in the Linux kernel. A KVM guest VM using virtio-net can crash the host by sending a short packet (i.e. size < ETHHLEN). The packet may traverse through vhost-net, macvtap and vlan without any validation/drop. When this packet is presented to mlx5 driver on the host side, the kernel panic happens since mlx5core assumes the frame size is always >= ETHHLEN.
This vulnerability affects both drivers/net/tun.c and drivers/net/tap.c. CVE-2024-41091 has been assigned to the TUN side of the issue.
Reference: https://www.openwall.com/lists/oss-security/2024/07/24/4
Other sources
CVE-2024-41090 In the Linux kernel, the following vulnerability has been resolved: tap: add missing verification for short frame The cited commit missed to check against the validity of the frame length in the tapgetuserxdp() path, which could cause a corrupted skb to be sent downstack. Even before the skb is transmitted, the tapgetuserxdp()-->skbsetnetworkheader() may assume the size is more than ETHHLEN. Once transmitted, this could either cause out-of-bound access beyond the actual length, or confuse the underlayer with incorrect or inconsistent header length in the skb metadata. In the alternative path, tapgetuser() already prohibits short frame which has the length less than Ethernet header size from being transmitted. This is to drop any frame shorter than the Ethernet header size just like how tapgetuser() does. CVE: CVE-2024-41090 CVE-2024-41091 In the Linux kernel, the following vulnerability has been resolved: tun: add missing verification for short frame The cited commit missed to check against the validity of the frame length in the tunxdpone() path, which could cause a corrupted skb to be sent downstack. Even before the skb is transmitted, the tunxdpone-->ethtypetrans() may access the Ethernet header although it can be less than ETHHLEN. Once transmitted, this could either cause out-of-bound access beyond the actual length, or confuse the underlayer with incorrect or inconsistent header length in the skb metadata. In the alternative path, tungetuser() already prohibits short frame which has the length less than Ethernet header size from being transmitted for IFFTAP. This is to drop any frame shorter than the Ethernet header size just like how tungetuser() does. CVE: CVE-2024-41091
— F5
Linux Kernel is vulnerable to a denial of service, caused by missing check against the validity of the frame length in the tunxdpone() path. By sending a specially crafted request, a local attacker could exploit this vulnerability to cause a denial of service condition.
— IBM
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2024-41091?
CVE-2024-41091 is classified as a denial-of-service (DoS) vulnerability.
How do I fix CVE-2024-41091?
To mitigate CVE-2024-41091, update to the specified remedial versions of the affected software.
Which products are affected by CVE-2024-41091?
CVE-2024-41091 affects F5 BIG-IP Next, F5 BIG-IP Next Central Manager, F5 Traffix Systems Signaling Delivery Controller, and certain versions of the Linux kernel.
What causes CVE-2024-41091?
CVE-2024-41091 is caused by a KVM guest VM sending a malformed short packet that crashes the host machine.
Is there a known workaround for CVE-2024-41091?
Currently, updating to the fixed versions is the recommended method for addressing CVE-2024-41091.