CVE-2026-43333: bpf: reject direct access to nullable PTR_TO_BUF pointers
In the Linux kernel, the following vulnerability has been resolved:
bpf: reject direct access to nullable PTRTOBUF pointers
checkmemaccess() matches PTRTOBUF via basetype() which strips PTRMAYBENULL, allowing direct dereference without a null check.
Map iterator ctx->key and ctx->value are PTRTOBUF | PTRMAYBENULL. On stop callbacks these are NULL, causing a kernel NULL dereference.
Add a typemaybenull() guard to the PTRTOBUF branch, matching the existing PTRTOBTFID pattern.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2026-43333?
CVE-2026-43333 has been classified with moderate severity due to the potential for memory corruption.
How do I fix CVE-2026-43333?
To fix CVE-2026-43333, update to the latest version of the Linux kernel that includes the relevant patches.
Which versions of the Linux kernel are affected by CVE-2026-43333?
CVE-2026-43333 affects multiple versions of the Linux kernel prior to the introduction of the patch addressing nullable PTR_TO_BUF pointers.
What impact does CVE-2026-43333 have?
CVE-2026-43333 can lead to a denial of service or execution of arbitrary code due to improper memory access.
Is CVE-2026-43333 related to other vulnerabilities?
Yes, CVE-2026-43333 is related to issues surrounding memory management within the Linux kernel.