Linux Kernel up to 6.15.3 mm memory corruption

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.15.3. Affected by this vulnerability is an unknown functionality of the component mm. Such manipulation leads to memory corruption. This vulnerability is referenced as CVE-2025-38207. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.15.3. Affected by this issue is an unknown function of the component mm. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: mm: fix uprobe pte be overwritten when expanding vma Patch series "Fix uprobe pte be overwritten when expanding vma". This patch (of 4): We encountered a BUG alert triggered by Syzkaller as follows: BUG: Bad rss-counter state mm:00000000b4a60fca type:MM_ANONPAGES val:1 And we can reproduce it with the following steps: 1. register uprobe on file at zero offset 2. mmap the file at zero offset: addr1 = mmap(NULL, 2 * 4096, PROT_NONE, MAP_PRIVATE, fd, 0); 3. mremap part of vma1 to new vma2: addr2 = mremap(addr1, 4096, 2 * 4096, MREMAP_MAYMOVE); 4. mremap back to orig addr1: mremap(addr2, 4096, 4096, MREMAP_MAYMOVE | MREMAP_FIXED, addr1); In step 3, the vma1 range [addr1, addr1 + 4096] will be remap to new vma2 with range [addr2, addr2 + 8192], and remap uprobe anon page from the vma1 to vma2, then unmap the vma1 range [addr1, addr1 + 4096]. In step 4, the vma2 range [addr2, addr2 + 4096] will be remap back to the addr range [addr1, addr1 + 4096]. Since the addr range [addr1 + 4096, addr1 + 8192] still maps the file, it will take vma_merge_new_range to expand the range, and then do uprobe_mmap in vma_complete. Since the merged vma pgoff is also zero offset, it will install uprobe anon page to the merged vma. However, the upcomming move_page_tables step, which use set_pte_at to remap the vma2 uprobe pte to the merged vma, will overwrite the newly uprobe pte in the merged vma, and lead that pte to be orphan. Since the uprobe pte will be remapped to the merged vma, we can remove the unnecessary uprobe_mmap upon merged vma. This problem was first found in linux-6.6.y and also exists in the community syzkaller: https://lore.kernel.org/all/[email protected]/T/

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2025-38207 since 04/16/2025. The exploitation is known to be easy. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 12/14/2025).

The vulnerability scanner Nessus provides a plugin with the ID 278484 (EulerOS 2.0 SP13 : kernel (EulerOS-SA-2025-2501)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.15.4 or 6.16-rc1 eliminates this vulnerability. Applying the patch 58b83b9a9a929611a2a2e7d88f45cb0d786b7ee0/2b12d06c37fd3a394376f42f026a7478d826ed63 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 (278484), EUVD (EUVD-2025-20049) and CERT Bund (WID-SEC-2025-1465). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• IBM QRadar SIEM
• SUSE openSUSE
• RESF Rocky Linux
• Dell Avamar
• Open Source Linux Kernel
• Dell NetWorker
• Dell Secure Connect Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.15.0
• 6.15.1
• 6.15.2
• 6.15.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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