CVE-2026-43333

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxb453361384c2db1c703dacb806d5fd36aec4ceca < 10bc4a4dcded509c5d5c67d497900c3922c604cdaffected
LinuxLinux20b2aff4bc15bda809f994761d5719827d66c0b4 < 21a10c06ffae24cb01fd174a7ab7736001d2ea56affected
LinuxLinux20b2aff4bc15bda809f994761d5719827d66c0b4 < 8755066f7bd0f4ac46a29d1708c7b20894539252affected
LinuxLinux20b2aff4bc15bda809f994761d5719827d66c0b4 < 70abd9d118da2f56beb4ec22e3a29becae373535affected
LinuxLinux20b2aff4bc15bda809f994761d5719827d66c0b4 < 63276547debc4d8a73eefb2c5273b2a905c961b0affected
LinuxLinux20b2aff4bc15bda809f994761d5719827d66c0b4 < 4f6c99dc0420f1a3d671c1b8ab8a7ac84d9cba09affected
LinuxLinux20b2aff4bc15bda809f994761d5719827d66c0b4 < b0db1accbc7395657c2b79db59fa9fae0d6656f3affected
LinuxLinuxe982070f8970bb62e69ed7c9cafff886ed200349affected
LinuxLinux5.15.37 < 5.15.203affected
LinuxLinux5.16.11 < 5.17affected
LinuxLinux5.17affected
LinuxLinux0 < 5.17unaffected
LinuxLinux5.15.203 <= 5.15.*unaffected
LinuxLinux6.1.168 <= 6.1.*unaffected
LinuxLinux6.6.134 <= 6.6.*unaffected
LinuxLinux6.12.81 <= 6.12.*unaffected
LinuxLinux6.18.22 <= 6.18.*unaffected
LinuxLinux6.19.12 <= 6.19.*unaffected
LinuxLinux7.0 <= *unaffected

Weaknesses

References