Merge pull request FEX-Emu#4322 from Sonicadvance1/protect_first_page…

…_altstack SignalDelegator: Protect first page of the altstack
pmatos · Feb 3, 2025 · 62cfc26 · 62cfc26
2 parents 713ebf1 + b01a6b9
commit 62cfc26
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/Source/Tools/LinuxEmulation/LinuxSyscalls/SignalDelegator.cpp b/Source/Tools/LinuxEmulation/LinuxSyscalls/SignalDelegator.cpp
@@ -961,6 +961,9 @@ void SignalDelegator::RegisterTLSState(FEX::HLE::ThreadStateObject* Thread) {
   // Copy the thread object to the start of the alt-stack
   memcpy(Thread->SignalInfo.AltStackPtr, &Thread, sizeof(void*));
 
+  // Protect the first page of the alt-stack for overflow protection.
+  mprotect(Thread->SignalInfo.AltStackPtr, 4096, PROT_READ);
+
   // Register the alt stack
   const int Result = sigaltstack(&altstack, nullptr);
   if (Result == -1) {