From 9366397f057d18401e680b2cb28a0ee17c59d4a6 Mon Sep 17 00:00:00 2001 From: Steven Wu Date: Wed, 18 Dec 2019 12:22:21 -0800 Subject: [libunwind] Fix evaluating DWARF operation DW_OP_pick reg is unsigned type and used here for getting array element from the end by negating it. negation of unsigned can result in large number and array access with that index will result in segmentation fault. Fixes: https://bugs.llvm.org/show_bug.cgi?id=43872 Patched by: kamlesh kumar Differential Revision: https://reviews.llvm.org/D69893 --- libunwind/src/DwarfInstructions.hpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'libunwind') diff --git a/libunwind/src/DwarfInstructions.hpp b/libunwind/src/DwarfInstructions.hpp index 48ef1866d6e1..ee98f538d437 100644 --- a/libunwind/src/DwarfInstructions.hpp +++ b/libunwind/src/DwarfInstructions.hpp @@ -433,7 +433,7 @@ DwarfInstructions::evaluateExpression(pint_t expression, A &addressSpace, // pick from reg = addressSpace.get8(p); p += 1; - value = sp[-reg]; + value = sp[-(int)reg]; *(++sp) = value; if (log) fprintf(stderr, "duplicate %d in stack\n", reg); -- cgit v1.2.1