CVE-2025-38364: Debian Linux

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: maple_tree: fix MA_STATE_PREALLOC flag in mas_preallocate() Temporarily clear the preallocation flag when explicitly requesting allocations. Pre-existing allocations are already counted against the request through mas_node_count_gfp(), but the allocations will not happen if the MA_STATE_PREALLOC flag is set. This flag is meant to avoid re-allocating in bulk allocation mode, and to detect issues with preallocation calculations. The MA_STATE_PREALLOC flag should also always be set on zero allocations so that detection of underflow allocations will print a WARN_ON() during consumption. User visible effect of this flaw is a WARN_ON() followed by a null pointer dereference when subsequent requests for larger number of nodes is ignored, such as the vma merge retry in mmap_region() caused by drivers altering the vma flags (which happens in v6.6, at least)

Affected products

• Debian Debian Linux: version 11.0 only
• Linux Linux Kernel: from 6.1, before 6.1.146 (fixed in 6.1.146); from 6.2, before 6.6.99 (fixed in 6.6.99); from 6.7, before 6.12.36 (fixed in 6.12.36); from 6.13, before 6.15.5 (fixed in 6.15.5); version 6.16 only

Published 2025-07-25. Last modified 2026-06-17.