CVE-2026-43333
bpf: reject direct access to nullable PTR_TO_BUF pointers
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Description
In the Linux kernel, the following vulnerability has been resolved: bpf: reject direct access to nullable PTR_TO_BUF pointers check_mem_access() matches PTR_TO_BUF via base_type() which strips PTR_MAYBE_NULL, allowing direct dereference without a null check. Map iterator ctx->key and ctx->value are PTR_TO_BUF | PTR_MAYBE_NULL. On stop callbacks these are NULL, causing a kernel NULL dereference. Add a type_may_be_null() guard to the PTR_TO_BUF branch, matching the existing PTR_TO_BTF_ID pattern.
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory references
- https://git.kernel.org/stable/c/10bc4a4dcded509c5d5c67d497900c3922c604cd
- https://git.kernel.org/stable/c/21a10c06ffae24cb01fd174a7ab7736001d2ea56
- https://git.kernel.org/stable/c/8755066f7bd0f4ac46a29d1708c7b20894539252
- https://git.kernel.org/stable/c/70abd9d118da2f56beb4ec22e3a29becae373535
- https://git.kernel.org/stable/c/63276547debc4d8a73eefb2c5273b2a905c961b0
References (7)
CVSS
- Attack Vector
- LOCAL
- Complexity
- LOW
- Privileges
- LOW
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality
- NONE
- Integrity
- NONE
- Availability
- HIGH
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