CVE-2025-38071

In the Linux kernel, the following vulnerability has been resolved:

x86/mm: Check return value from memblockphysalloc_range()

At least with CONFIGPHYSICALSTART=0x100000, if there is < 4 MiB of contiguous free memory available at this point, the kernel will crash and burn because memblockphysallocrange() returns 0 on failure, which leads memblockphys_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.