CVE-2026-72172
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
In the Linux kernel, a bug was found in mm/mm_init regarding uninitialized struct pages for ZONE_DEVICE. When DAX memory is hotplugged into an unoccupied subsection of an early section, section_activate() reuses the unoptimized boot memmap, but compound_nr_pages() still assumes optimization and initializes only a reduced number of pages. The remaining pages are left uninitialized, which can lead to unexpected behavior or crashes.
Risk Assessment
The risk includes potential system crashes or unpredictable behavior due to uninitialized memory pages. This could affect the stability of systems using DAX memory.
Recommendation
It is recommended to apply the Linux kernel patch that treats early sections as unoptimized when calculating how many pages to initialize. Update systems, especially those using DAX.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: mm/mm_init: fix uninitialized struct pages for ZONE_DEVICE If DAX memory is hotplugged into an unoccupied subsection of an early section, section_activate() reuses the unoptimized boot memmap. However, compound_nr_pages() still assumes that vmemmap optimization is in effect and initializes only the reduced number of struct pages. As a result, the remaining tail struct pages are left uninitialized, which can later lead to unexpected behavior or crashes. Fix this by treating early sections as unoptimized when calculating how many struct pages to initialize.