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CVE-2024-57945

riscv: mm: Fix the out of bound issue of vmemmap address

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.10.258, 6.1.140, 6.6.72, 5.16, 6.8
None on Exploit-DB, Metasploit or GitHub

Summary

In the Linux kernel, the following vulnerability has been resolved: riscv: mm: Fix the out of bound issue of vmemmap address In sparse vmemmap model, the virtual address of vmemmap is calculated as: ((struct page *)VMEMMAP_START - (phys_ram_base >> PAGE_SHIFT)). And the struct page's va can be calculated with an offset: (vmemmap + (pfn)). However, when initializing struct pages, kernel actually starts from the first page from the same section that phys_ram_base belongs to. If the first page's physical address is not (phys_ram_base >> PAGE_SHIFT), then we get an va below VMEMMAP_START when calculating va for it's struct page. For example, if phys_ram_base starts from 0x82000000 with pfn 0x82000, the first page in the same section is actually pfn 0x80000. During init_unavailable_range(), we will initialize struct page for pfn 0x80000 with virtual address ((struct page *)VMEMMAP_START - 0x2000), which is below VMEMMAP_START as well as PCI_IO_END. This commit fixes this bug by introducing a new variable 'vmemmap_start_pfn' which is aligned with memory section size and using it to calculate vmemmap address instead of phys_ram_base.

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • Linux Linux

    From 5.10.212 · fixed in 5.10.258; From 6.1.81 · fixed in 6.1.140; From 6.6.21 · fixed in 6.6.72; From 5.15.151 · fixed in 5.16; From 6.7.9 · fixed in 6.8

  • Linux Linux

    6.8

References 5

git.kernel.org