From d7cbfcf36ace575ec90434624279dd3ebce78c47 Mon Sep 17 00:00:00 2001 From: Fangrui Song Date: Fri, 5 Aug 2022 18:24:53 -0700 Subject: [PATCH] [ELF][AArch64] Fix potentially corrupted section content for PAC D74537 introduced a bug: if `(config->andFeatures & GNU_PROPERTY_AARCH64_FEATURE_1_PAC) != 0` with -z pac-plt unspecified, we incorrectly use AArch64BtiPac, whose writePlt will make out-of-bounds write after the .plt section. This is often benign because the output section after .plt will usually overwrite the content. This is very difficult to test without D131247 (Parallelize writes of different OutputSections). --- lld/ELF/Arch/AArch64.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lld/ELF/Arch/AArch64.cpp b/lld/ELF/Arch/AArch64.cpp index 807e5dda9d5b..fc564ab6f15a 100644 --- a/lld/ELF/Arch/AArch64.cpp +++ b/lld/ELF/Arch/AArch64.cpp @@ -884,8 +884,8 @@ void AArch64BtiPac::writePlt(uint8_t *buf, const Symbol &sym, } static TargetInfo *getTargetInfo() { - if (config->andFeatures & (GNU_PROPERTY_AARCH64_FEATURE_1_BTI | - GNU_PROPERTY_AARCH64_FEATURE_1_PAC)) { + if ((config->andFeatures & GNU_PROPERTY_AARCH64_FEATURE_1_BTI) || + config->zPacPlt) { static AArch64BtiPac t; return &t; }