Slab-Out-of-Bounds Vulnerability in Linux Kernel efivarfs Product by Linux Foundation

CVE-2025-39817

What is CVE-2025-39817?

A vulnerability in the Linux kernel's efivarfs component can lead to a slab-out-of-bounds condition when valid entries are not properly verified during concurrent lookups. This issue arises when the length of a dentry's name is less than the length of the EFI variable GUID, which can result in a negative value for the 'guid' variable. Consequently, if invalid directory entries are added to the hash list during parallel lookups, it can lead to out-of-bounds memory access during comparison operations. The issue has been mitigated by implementing checks on the 'guid' before performing the comparison to prevent potential exploitation.

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