Linux Kernel up to 6.12.4 fpmr_set uninitialized pointer

Summaryinfo

A vulnerability categorized as problematic has been discovered in Linux Kernel up to 6.12.4. Affected by this vulnerability is the function fpmr_set. Such manipulation leads to uninitialized pointer. This vulnerability is documented as CVE-2024-57878. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.4 and classified as problematic. Affected by this issue is the function fpmr_set. The manipulation with an unknown input leads to a uninitialized pointer vulnerability. Using CWE to declare the problem leads to CWE-824. The product accesses or uses a pointer that has not been initialized. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: arm64: ptrace: fix partial SETREGSET for NT_ARM_FPMR Currently fpmr_set() doesn't initialize the temporary 'fpmr' variable, and a SETREGSET call with a length of zero will leave this uninitialized. Consequently an arbitrary value will be written back to target->thread.uw.fpmr, potentially leaking up to 64 bits of memory from the kernel stack. The read is limited to a specific slot on the stack, and the issue does not provide a write mechanism. Fix this by initializing the temporary value before copying the regset from userspace, as for other regsets (e.g. NT_PRSTATUS, NT_PRFPREG, NT_ARM_SYSTEM_CALL). In the case of a zero-length write, the existing contents of FPMR will be retained. Before this patch: | # ./fpmr-test | Attempting to write NT_ARM_FPMR::fpmr = 0x900d900d900d900d | SETREGSET(nt=0x40e, len=8) wrote 8 bytes | | Attempting to read NT_ARM_FPMR::fpmr | GETREGSET(nt=0x40e, len=8) read 8 bytes | Read NT_ARM_FPMR::fpmr = 0x900d900d900d900d | | Attempting to write NT_ARM_FPMR (zero length) | SETREGSET(nt=0x40e, len=0) wrote 0 bytes | | Attempting to read NT_ARM_FPMR::fpmr | GETREGSET(nt=0x40e, len=8) read 8 bytes | Read NT_ARM_FPMR::fpmr = 0xffff800083963d50 After this patch: | # ./fpmr-test | Attempting to write NT_ARM_FPMR::fpmr = 0x900d900d900d900d | SETREGSET(nt=0x40e, len=8) wrote 8 bytes | | Attempting to read NT_ARM_FPMR::fpmr | GETREGSET(nt=0x40e, len=8) read 8 bytes | Read NT_ARM_FPMR::fpmr = 0x900d900d900d900d | | Attempting to write NT_ARM_FPMR (zero length) | SETREGSET(nt=0x40e, len=0) wrote 0 bytes | | Attempting to read NT_ARM_FPMR::fpmr | GETREGSET(nt=0x40e, len=8) read 8 bytes | Read NT_ARM_FPMR::fpmr = 0x900d900d900d900d

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2024-57878 since 01/11/2025. The exploitation is known to be difficult. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 230823 (Linux Distros Unpatched Vulnerability : CVE-2024-57878), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.5 eliminates this vulnerability. Applying the patch 8ab73c34e3c5b580721696665eabd799346bc50b/f5d71291841aecfe5d8435da2dfa7f58ccd18bc8 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 (230823) and CERT Bund (WID-SEC-2025-0047). Once again VulDB remains the best source for vulnerability data.

Affected

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

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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