x86/mm: Don't apply va_align to hugetlb mappings on AMD F15h

Overview

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

x86/mm: Don't apply va_align to hugetlb mappings on AMD F15h

get_align_mask() returns huge_page_mask_align() for hugetlbfs, but get_align_bits() adds va_align.bits regardless, so vm_unmapped_area() returns an address off the huge page boundary and __unmap_hugepage_range() hits BUG_ON(start & ~huge_page_mask(h)) at teardown.

This can be triggered on Carrizo and FX-8370E, both hstates.

Pass the file to get_align_bits() and skip the randomisation for hugetlbfs.

[ bp: Massage commit message. ]

Affected

• Linux >= 1317a5e7f7b1336eac4097f0ef4f5cd7ae72f1d0 < fe23680e6f1d52b8cc45d77bf7c54249508a81c7
• Linux >= 1317a5e7f7b1336eac4097f0ef4f5cd7ae72f1d0 < b46b2e2de47ca9449532b0a7110ed99f79061d6e
• Linux >= 1317a5e7f7b1336eac4097f0ef4f5cd7ae72f1d0 < d2457a7e2727dc747a61a50d65c2f259afce8c45
• Linux 6.13

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.