CVE-2026-43333: bpf: reject direct access to nullable PTR_TO_BUF pointers

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 products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

b453361384c2db1c703dacb806d5fd36aec4ceca to < 10bc4a4dcded509c5d5c67d497900c3922c604cdaffected
20b2aff4bc15bda809f994761d5719827d66c0b4 to < 21a10c06ffae24cb01fd174a7ab7736001d2ea56affected
20b2aff4bc15bda809f994761d5719827d66c0b4 to < 8755066f7bd0f4ac46a29d1708c7b20894539252affected
20b2aff4bc15bda809f994761d5719827d66c0b4 to < 70abd9d118da2f56beb4ec22e3a29becae373535affected
20b2aff4bc15bda809f994761d5719827d66c0b4 to < 63276547debc4d8a73eefb2c5273b2a905c961b0affected
20b2aff4bc15bda809f994761d5719827d66c0b4 to < 4f6c99dc0420f1a3d671c1b8ab8a7ac84d9cba09affected
20b2aff4bc15bda809f994761d5719827d66c0b4 to < b0db1accbc7395657c2b79db59fa9fae0d6656f3affected
e982070f8970bb62e69ed7c9cafff886ed200349affected
5.15.37 to < 5.15.203affected
5.16.11 to < 5.17affected

Linux Linux

Default version status: affected

5.17affected
0 to < 5.17unaffected
5.15.203 to ≤ 5.15.*unaffected
6.1.168 to ≤ 6.1.*unaffected
6.6.134 to ≤ 6.6.*unaffected
6.12.81 to ≤ 6.12.*unaffected
6.18.22 to ≤ 6.18.*unaffected
6.19.12 to ≤ 6.19.*unaffected
7.0 to ≤ *unaffected

CVE-2026-43333

bpf: reject direct access to nullable PTR_TO_BUF pointers

Description

Affected products

Linux Linux

Linux Linux

References