System crash via unchecked skb size overflow
Published Oct 13, 2023 · Updated Aug 2, 2024
Integer overflow in the Linux kernel through 6.5.7 allows local users to crash the system through an oversized skb allocation. __alloc_skb passes a user-controlled unsigned size to kmalloc_size_roundup, where a large value wraps to zero and is treated as a valid kernel pointer. Access to an unprivileged user namespace is sufficient; SMAP-enabled systems panic during skb_shared_info initialization, while systems without SMAP expose userspace-backed function pointers.
Summary
What happened
Integer overflow in the Linux kernel through 6.5.7 allows local users to crash the system through an oversized skb allocation. __alloc_skb passes a user-controlled unsigned size to kmalloc_size_roundup, where a large value wraps to zero and is treated as a valid kernel pointer. Access to an unprivileged user namespace is sufficient; SMAP-enabled systems panic during skb_shared_info initialization, while systems without SMAP expose userspace-backed function pointers.
The record
- CVE
- CVE-2023-42752
- Published
- Oct 13, 2023
- Updated
- Aug 2, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-190, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 13, 2023CVE publishedPublication date reported by the CVE source.
- Aug 2, 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
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Technologies
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