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PR22361 readelf buffer overflow on fuzzed archive header
- From: Alan Modra <amodra at gmail dot com>
- To: binutils at sourceware dot org
- Date: Sat, 28 Oct 2017 22:15:56 +1030
- Subject: PR22361 readelf buffer overflow on fuzzed archive header
- Authentication-results: sourceware.org; auth=none
PR 22361
* readelf.c (process_archive_index_and_symbols): Ensure ar_size
field is zero terminated for strtoul.
(setup_archive, get_archive_member_name): Likewise.
diff --git a/binutils/elfcomm.c b/binutils/elfcomm.c
index 0db8948..80f3fd8 100644
--- a/binutils/elfcomm.c
+++ b/binutils/elfcomm.c
@@ -466,8 +466,12 @@ process_archive_index_and_symbols (struct archive_info * arch,
{
size_t got;
unsigned long size;
+ char fmag_save;
+ fmag_save = arch->arhdr.ar_fmag[0];
+ arch->arhdr.ar_fmag[0] = 0;
size = strtoul (arch->arhdr.ar_size, NULL, 10);
+ arch->arhdr.ar_fmag[0] = fmag_save;
/* PR 17531: file: 912bd7de. */
if ((signed long) size < 0)
{
@@ -655,7 +659,10 @@ setup_archive (struct archive_info *arch, const char *file_name,
if (const_strneq (arch->arhdr.ar_name, "// "))
{
/* This is the archive string table holding long member names. */
+ char fmag_save = arch->arhdr.ar_fmag[0];
+ arch->arhdr.ar_fmag[0] = 0;
arch->longnames_size = strtoul (arch->arhdr.ar_size, NULL, 10);
+ arch->arhdr.ar_fmag[0] = fmag_save;
/* PR 17531: file: 01068045. */
if (arch->longnames_size < 8)
{
@@ -758,6 +765,7 @@ get_archive_member_name (struct archive_info *arch,
char *endp;
char *member_file_name;
char *member_name;
+ char fmag_save;
if (arch->longnames == NULL || arch->longnames_size == 0)
{
@@ -766,9 +774,12 @@ get_archive_member_name (struct archive_info *arch,
}
arch->nested_member_origin = 0;
+ fmag_save = arch->arhdr.ar_fmag[0];
+ arch->arhdr.ar_fmag[0] = 0;
k = j = strtoul (arch->arhdr.ar_name + 1, &endp, 10);
if (arch->is_thin_archive && endp != NULL && * endp == ':')
arch->nested_member_origin = strtoul (endp + 1, NULL, 10);
+ arch->arhdr.ar_fmag[0] = fmag_save;
if (j > arch->longnames_size)
{
--
Alan Modra
Australia Development Lab, IBM