CVE-2025-38586

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> bpf, arm64: Fix fp initialization for exception boundary<br /> <br /> In the ARM64 BPF JIT when prog-&gt;aux-&gt;exception_boundary is set for a BPF<br /> program, find_used_callee_regs() is not called because for a program<br /> acting as exception boundary, all callee saved registers are saved.<br /> find_used_callee_regs() sets `ctx-&gt;fp_used = true;` when it sees FP<br /> being used in any of the instructions.<br /> <br /> For programs acting as exception boundary, ctx-&gt;fp_used remains false<br /> even if frame pointer is used by the program and therefore, FP is not<br /> set-up for such programs in the prologue. This can cause the kernel to<br /> crash due to a pagefault.<br /> <br /> Fix it by setting ctx-&gt;fp_used = true for exception boundary programs as<br /> fp is always saved in such programs.