CVE-2026-43333
bpf: reject direct access to nullable PTR_TO_BUF pointers
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 5.15.203, 5.17
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
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.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 5.15.37 · fixed in 5.15.203; From 5.16.11 · fixed in 5.17
- Linux Linux
5.17
References 7
git.kernel.org
- stable/c/10bc4a4dcded509c5d5c67d497900c3922c604cd
- stable/c/21a10c06ffae24cb01fd174a7ab7736001d2ea56
- stable/c/8755066f7bd0f4ac46a29d1708c7b20894539252
- stable/c/70abd9d118da2f56beb4ec22e3a29becae373535
- stable/c/63276547debc4d8a73eefb2c5273b2a905c961b0
- stable/c/4f6c99dc0420f1a3d671c1b8ab8a7ac84d9cba09
- stable/c/b0db1accbc7395657c2b79db59fa9fae0d6656f3