CVE-2026-45903

In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix memory access flags in helper prototypes

After commit 37cce22dbd51 ("bpf: verifier: Refactor helper access type tracking"), the verifier started relying on the access type flags in helper function prototypes to perform memory access optimizations.

Currently, several helper functions utilizing ARGPTRTOMEM lack the corresponding MEMRDONLY or MEM_WRITE flags. This omission causes the verifier to incorrectly assume that the buffer contents are unchanged across the helper call. Consequently, the verifier may optimize away subsequent reads based on this wrong assumption, leading to correctness issues.

For bpfgetstackprotorawtp, the original MEMRDONLY was incorrect since the helper writes to the buffer. Change it to ARGPTRTOUNINITMEM which correctly indicates write access to potentially uninitialized memory.

Similar issues were recently addressed for specific helpers in commit ac44dcc788b9 ("bpf: Fix verifier assumptions of bpfdpath's output buffer") and commit 2eb7648558a7 ("bpf: Specify access type of bpfsysctlget_name args").

Fix these prototypes by adding the correct memory access flags.