mm/hugetlb: initialize gigantic bootmem hugepage struct pages earlier

Summary

In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: initialize gigantic bootmem hugepage struct pages earlier Gigantic bootmem HugeTLB pages are currently initialized from hugetlb_init(), but page_alloc_init_late() runs earlier and walks pageblocks to determine zone contiguity. If a bootmem HugeTLB region is marked noinit, set_zone_contiguous() can observe still-uninitialized struct pages through __pageblock_pfn_to_page(). This may not trigger an immediate failure, but it can make set_zone_contiguous() compute the wrong zone contiguity state. If extra poisoned-page checks are added in this path, such as PF_POISONED_CHECK() in page_zone_id(), it can also trigger an early boot panic. Initialize gigantic bootmem HugeTLB struct pages from page_alloc_init_late(), before zone contiguity is evaluated, so later page allocator setup only sees valid struct page state. This also makes the initialization order more natural, as struct pages should be initialized before later code inspects them.

Timeline

1. Sep 24, 2026, 3:29 PM UTCCVE published
2. Oct 21, 2026, 12:52 PM UTCRecord last updated

Affected versions

• Linux Linux

  From fde1c4ecf91640e5a95ec36b71ec2e8ec379ce40 · fixed in 326de479ab5942fb4a4aa4f20c716045434fcd6b; From fde1c4ecf91640e5a95ec36b71ec2e8ec379ce40 · fixed in 09505232eced5f1c42902d8f28740f070c3fc6dc; From fde1c4ecf91640e5a95ec36b71ec2e8ec379ce40 · fixed in 29968bc7aefb3cf1e72aa7c5f52697a6b0527094; From fde1c4ecf91640e5a95ec36b71ec2e8ec379ce40 · fixed in b1b7c045e808c761b1cc8c19b3040fadedda3fef

• Linux Linux

  6.7

• KernelLinux

  From 6.7.0 · fixed in 6.12.114; From 6.13.0 · fixed in 6.18.51; From 6.19.0 · fixed in 7.2.4

References 4