Linux Kernel up to 6.17.5 z_erofs_submit_queue compressed_bvecs[] out-of-bounds

Summaryinfo

A vulnerability identified as critical has been detected in Linux Kernel up to 6.17.5. Affected by this vulnerability is the function z_erofs_submit_queue. The manipulation of the argument compressed_bvecs[] leads to out-of-bounds. This vulnerability is documented as CVE-2025-40241. It is possible to launch the attack on the physical device. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.17.5 and classified as problematic. This issue affects the function z_erofs_submit_queue. The manipulation of the argument compressed_bvecs[] with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: erofs: fix crafted invalid cases for encoded extents Robert recently reported two corrupted images that can cause system crashes, which are related to the new encoded extents introduced in Linux 6.15: - The first one [1] has plen != 0 (e.g. plen == 0x2000000) but (plen & Z_EROFS_EXTENT_PLEN_MASK) == 0. It is used to represent special extents such as sparse extents (!EROFS_MAP_MAPPED), but previously only plen == 0 was handled; - The second one [2] has pa 0xffffffffffdcffed and plen 0xb4000, then "cur [0xfffffffffffff000] += bvec.bv_len [0x1000]" in "} while ((cur += bvec.bv_len) < end);" wraps around, causing an out-of-bound access of pcl->compressed_bvecs[] in z_erofs_submit_queue(). EROFS only supports 48-bit physical block addresses (up to 1EiB for 4k blocks), so add a sanity check to enforce this.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2025-40241 since 04/16/2025. An attack has to be approached locally. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 277670 (Linux Distros Unpatched Vulnerability : CVE-2025-40241), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.17.6 eliminates this vulnerability. Applying the patch 00d8fe0b72f4ca0a983abced36aad2160038c421/a429b76114aaca3ef1aff4cd469dcf025431bd11 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 databases at Tenable (277670) and CERT Bund (WID-SEC-2025-2747). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

• Debian Linux
• Google Cloud Platform
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux
• Microsoft Azure Linux

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.17.0
• 6.17.1
• 6.17.2
• 6.17.3
• 6.17.4
• 6.17.5

License

• open-source

Website

• Vendor: https://www.kernel.org/

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