Branch: refs/heads/main Home: https://github.com/WebKit/WebKit Commit: 3e3d0883c84955472ece1b2f2e63f31522c5440d https://github.com/WebKit/WebKit/commit/3e3d0883c84955472ece1b2f2e63f31522c5440d Author: Keith Miller <keith_mil...@apple.com> Date: 2024-05-20 (Mon, 20 May 2024)
Changed paths: M Source/JavaScriptCore/assembler/MacroAssemblerARM64E.h M Source/JavaScriptCore/dfg/DFGOSRExitCompilerCommon.cpp M Source/JavaScriptCore/jit/ThunkGenerators.cpp M Source/JavaScriptCore/llint/LLIntThunks.cpp M Source/JavaScriptCore/runtime/Options.cpp M Source/JavaScriptCore/runtime/OptionsList.h M Source/WTF/wtf/PtrTag.h M Source/WebKit/WebProcess/WebProcess.cpp M Tools/Scripts/run-jsc-stress-tests Log Message: ----------- Make it harder to get a PAC signing gadget in JIT code. https://bugs.webkit.org/show_bug.cgi?id=272750 rdar://125596635 Reviewed by Yusuke Suzuki. Right now if an attacker can control where code is allocated they can overlap code to create a PAC bypass. This patch makes that harder (in the WebContent process) by only allowing pacibsp and pacizb. This means that during arity fixup we now tag the return PC with pacizb. This is ok because we don't use the zero diversifier for anything. For reifying inlined call frames during OSR exit things are a bit more complicated. First we have be careful to only move signed return addresses into lr then untag them there. Also, we have to shuffle SP to point to where it would in reified frame. This means that there is technically live data below our SP, which on many OSes causes problems. Talking to our kernel folks however this isn't a problem as long as we don't have any signal handlers or run lldb expressions in this window. We don't use signal handlers in the WebContent process and this patch tries to limit/document the window of JIT code where lldb would trash the stack. * Source/JavaScriptCore/assembler/MacroAssemblerARM64E.h: (JSC::MacroAssemblerARM64E::tagPtr): * Source/JavaScriptCore/dfg/DFGOSRExitCompilerCommon.cpp: (JSC::DFG::reifyInlinedCallFrames): (JSC::AssemblyHelpers::transferReturnPC): * Source/JavaScriptCore/jit/ThunkGenerators.cpp: (JSC::arityFixupGenerator): * Source/JavaScriptCore/llint/LLIntThunks.cpp: (JSC::LLInt::tagGateThunk): (JSC::LLInt::untagGateThunk): * Source/JavaScriptCore/runtime/OptionsList.h: * Source/WTF/wtf/PtrTag.h: * Source/WebKit/WebProcess/WebProcess.cpp: (WebKit::WebProcess::initializeProcess): * Tools/Scripts/run-jsc-stress-tests: Originally-landed-as: f442fbe222f3. rdar://128091836 Canonical link: https://commits.webkit.org/278996@main To unsubscribe from these emails, change your notification settings at https://github.com/WebKit/WebKit/settings/notifications _______________________________________________ webkit-changes mailing list webkit-changes@lists.webkit.org https://lists.webkit.org/mailman/listinfo/webkit-changes