CVE-2025-40349

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 6.17.0-rc2-gc17b750b3ad9

Description The Linux kernel's HFS Plus file system implementation contained a flaw in the hfsplus bmap alloc function. Specifically, insufficient validation of record offsets and lengths could lead to out-of-bounds memory access when allocating free nodes. This occurs because the function retrieves bitmap information using a node's page and offset/length values obtained from hfs brec lenoff. If these retrieved values are invalid (exceeding node size), the code may access pages outside the allocated range for that node. The issue was addressed by adding validation of both offset and length before use, preventing out-of-bounds page access. The functions is bnode offset valid and check and correct requested length were moved to hfsplus fs.h as they may be required by other functions.

Recommendations Linux kernel versions prior to 6.17.0-rc2-gc17b750b3ad9 should be updated to a newer version that includes the fix.