From 5cc4ca837deac7dc962d8a3741aa120c50ab41da Mon Sep 17 00:00:00 2001 From: Sergei Trofimovich Date: Sat, 24 Jun 2017 18:40:41 +0100 Subject: [PATCH] fix out-of-bounds access in elf.c:find_link The out-of-bounds access is reproducible on 'ia64-strip' command (see sample from https://bugs.gentoo.org/show_bug.cgi?id=622500) The output file contains less section than original one. This tricks 'hint' access to go out-of-bounds: * elf.c (find_link): Bounds check "hint". --- bfd/ChangeLog | 4 ++++ bfd/elf.c | 6 ++++-- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index f7ef5e1483b..945cb68e4b8 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,7 @@ +2017-06-25 Sergei Trofimovich + + * elf.c (find_link): Bounds check "hint". + 2017-06-24 Thomas Preud'homme * elf32-arm.c (using_thumb_only): Update list of architectures in diff --git a/bfd/elf.c b/bfd/elf.c index 5f37e7f79c7..76c6a5c6a7c 100644 --- a/bfd/elf.c +++ b/bfd/elf.c @@ -1283,7 +1283,8 @@ section_match (const Elf_Internal_Shdr * a, to be the correct section. */ static unsigned int -find_link (const bfd * obfd, const Elf_Internal_Shdr * iheader, const unsigned int hint) +find_link (const bfd *obfd, const Elf_Internal_Shdr *iheader, + const unsigned int hint) { Elf_Internal_Shdr ** oheaders = elf_elfsections (obfd); unsigned int i; @@ -1291,7 +1292,8 @@ find_link (const bfd * obfd, const Elf_Internal_Shdr * iheader, const unsigned i BFD_ASSERT (iheader != NULL); /* See PR 20922 for a reproducer of the NULL test. */ - if (oheaders[hint] != NULL + if (hint < elf_numsections (obfd) + && oheaders[hint] != NULL && section_match (oheaders[hint], iheader)) return hint; -- 2.30.2