CVE-2025-38071

Summary

In the Linux kernel, the following vulnerability has been resolved: x86/mm: Check return value from memblock_phys_alloc_range() At least with CONFIG_PHYSICAL_START=0x100000, if there is < 4 MiB of contiguous free memory available at this point, the kernel will crash and burn because memblock_phys_alloc_range() returns 0 on failure, which leads memblock_phys_free() to throw the first 4 MiB of physical memory to the wolves. At a minimum it should fail gracefully with a meaningful diagnostic, but in fact everything seems to work fine without the weird reserve allocation.

Impact & exploitability

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products we track (2)

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

Official patch: https://git.kernel.org/stable/c/631ca8909fd5c62b9fda9edda93924311a78a9c4 ↗

Additional information

• NVD record
• https://git.kernel.org/stable/c/631ca8909fd5c62b9fda9edda93924311a78a9c4Patch
• https://git.kernel.org/stable/c/8c18c904d301ffeb33b071eadc55cd6131e1e9bePatch
• https://git.kernel.org/stable/c/bffd5f2815c5234d609725cd0dc2f4bc5de2fc67Patch
• https://git.kernel.org/stable/c/c6f2694c580c27dca0cf7546ee9b4bfa6b940e38Patch
• https://git.kernel.org/stable/c/dde4800d2b0f68b945fd81d4fc2d4a10ae25f743Patch
• https://lists.debian.org/debian-lts-announce/2025/10/msg00008.htmlAdvisory
• https://cert-portal.siemens.com/productcert/html/ssa-082556.html