Kernel code execution via dangling VMA mapping
Published Oct 9, 2022 · Updated Aug 3, 2024
Use-after-free in mm/rmap.c in Linux kernel before 5.19.7 allows local users to crash the system or execute kernel code. anon_vma_clone misreads a combined child-and-VMA degree counter and reuses a leaf anon_vma twice, letting vma_merge leave page->mapping pointing to freed memory. Triggering requires local low-privilege access and a crafted fork, mapping, merge, and MADV_PAGEOUT sequence; successful exploitation reaches kernel context.
Summary
What happened
Use-after-free in mm/rmap.c in Linux kernel before 5.19.7 allows local users to crash the system or execute kernel code. anon_vma_clone misreads a combined child-and-VMA degree counter and reuses a leaf anon_vma twice, letting vma_merge leave page->mapping pointing to freed memory. Triggering requires local low-privilege access and a crafted fork, mapping, merge, and MADV_PAGEOUT sequence; successful exploitation reaches kernel context.
The record
- CVE
- CVE-2022-42703
- Published
- Oct 9, 2022
- Updated
- Aug 3, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-416, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 9, 2022CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
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Published CVSS scores
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Attacks
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Public exploit references
- Bringing back the stack attackproof of concept · demonstrated
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Technologies
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