From e021a55abd8b98acc6d29e00b8c36c5ee6e69b13 Mon Sep 17 00:00:00 2001
From: LC <mai.iam2048@gmail.com>
Date: Sat, 11 Jul 2026 12:04:36 -0400
Subject: [PATCH] BPFEmitter: Amend instruction class checking in HandleStore()

This was previously checking for a load class, which would result in ST
clobbering the index register.
---
 .../Tools/LinuxEmulation/LinuxSyscalls/Seccomp/BPFEmitter.cpp   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Source/Tools/LinuxEmulation/LinuxSyscalls/Seccomp/BPFEmitter.cpp b/Source/Tools/LinuxEmulation/LinuxSyscalls/Seccomp/BPFEmitter.cpp
index 39890d359..be75a67cb 100644
--- a/Source/Tools/LinuxEmulation/LinuxSyscalls/Seccomp/BPFEmitter.cpp
+++ b/Source/Tools/LinuxEmulation/LinuxSyscalls/Seccomp/BPFEmitter.cpp
@@ -110,7 +110,7 @@ uint64_t BPFEmitter::HandleStore(uint32_t BPFIP, const sock_filter* Inst) {
 
   [[maybe_unused]] size_t OpSize {};
 
-  const auto SrcReg = BPF_CLASS(Inst->code) == BPF_LD ? REG_A : REG_X;
+  const auto SrcReg = BPF_CLASS(Inst->code) == BPF_ST ? REG_A : REG_X;
   // Must be smaller than scratch space size.
   VALIDATE(Inst->k < 16);