Linux Kernel up to 6.11.5 bpf emit_a64_mov_i64 heap-based overflow

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.11.5 and classified as critical. Affected by this issue is the function emit_a64_mov_i64 of the component bpf. Executing a manipulation can lead to heap-based overflow. The identification of this vulnerability is CVE-2024-50203. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.11.5 and classified as critical. This vulnerability affects the function emit_a64_mov_i64 of the component bpf. The manipulation with an unknown input leads to a heap-based overflow vulnerability. The CWE definition for the vulnerability is CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: bpf, arm64: Fix address emission with tag-based KASAN enabled When BPF_TRAMP_F_CALL_ORIG is enabled, the address of a bpf_tramp_image struct on the stack is passed during the size calculation pass and an address on the heap is passed during code generation. This may cause a heap buffer overflow if the heap address is tagged because emit_a64_mov_i64() will emit longer code than it did during the size calculation pass. The same problem could occur without tag-based KASAN if one of the 16-bit words of the stack address happened to be all-ones during the size calculation pass. Fix the problem by assuming the worst case (4 instructions) when calculating the size of the bpf_tramp_image address emission.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2024-50203 since 10/21/2024. The exploitation appears to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 02/11/2025).

The vulnerability scanner Nessus provides a plugin with the ID 216030 (EulerOS 2.0 SP12 : kernel (EulerOS-SA-2025-1176)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.11.6 eliminates this vulnerability. Applying the patch 7db1a2121f3c/a552e2ef5fd1 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 (216030). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.11.0
• 6.11.1
• 6.11.2
• 6.11.3
• 6.11.4
• 6.11.5

License

• open-source

Website

• Vendor: https://www.kernel.org/

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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