Prevent attempts to call strncpy with a zero-length field by chacking the size of debuglink sections.

PR 22794
	* opncls.c (bfd_get_debug_link_info_1): Check the size of the
	section before attempting to read it in.
	(bfd_get_alt_debug_link_info): Likewise.
This commit is contained in:
Nick Clifton 2018-02-06 15:48:29 +00:00
parent 422f3d3d6d
commit 64e234d417
2 changed files with 24 additions and 5 deletions

View File

@ -1,3 +1,10 @@
2018-02-06 Nick Clifton <nickc@redhat.com>
PR 22794
* opncls.c (bfd_get_debug_link_info_1): Check the size of the
section before attempting to read it in.
(bfd_get_alt_debug_link_info): Likewise.
2018-02-06 Paul Carroll <pcarroll@codesourcery.com>
* bfd/dwarf2.c (find_abstract_name): Modified to return file and

View File

@ -1179,6 +1179,7 @@ bfd_get_debug_link_info_1 (bfd *abfd, void *crc32_out)
bfd_byte *contents;
unsigned int crc_offset;
char *name;
bfd_size_type size;
BFD_ASSERT (abfd);
BFD_ASSERT (crc32_out);
@ -1188,6 +1189,12 @@ bfd_get_debug_link_info_1 (bfd *abfd, void *crc32_out)
if (sect == NULL)
return NULL;
size = bfd_get_section_size (sect);
/* PR 22794: Make sure that the section has a reasonable size. */
if (size < 8 || size >= bfd_get_size (abfd))
return NULL;
if (!bfd_malloc_and_get_section (abfd, sect, &contents))
{
if (contents != NULL)
@ -1197,10 +1204,10 @@ bfd_get_debug_link_info_1 (bfd *abfd, void *crc32_out)
/* CRC value is stored after the filename, aligned up to 4 bytes. */
name = (char *) contents;
/* PR 17597: avoid reading off the end of the buffer. */
crc_offset = strnlen (name, bfd_get_section_size (sect)) + 1;
/* PR 17597: Avoid reading off the end of the buffer. */
crc_offset = strnlen (name, size) + 1;
crc_offset = (crc_offset + 3) & ~3;
if (crc_offset + 4 > bfd_get_section_size (sect))
if (crc_offset + 4 > size)
return NULL;
*crc32 = bfd_get_32 (abfd, contents + crc_offset);
@ -1261,6 +1268,7 @@ bfd_get_alt_debug_link_info (bfd * abfd, bfd_size_type *buildid_len,
bfd_byte *contents;
unsigned int buildid_offset;
char *name;
bfd_size_type size;
BFD_ASSERT (abfd);
BFD_ASSERT (buildid_len);
@ -1271,6 +1279,10 @@ bfd_get_alt_debug_link_info (bfd * abfd, bfd_size_type *buildid_len,
if (sect == NULL)
return NULL;
size = bfd_get_section_size (sect);
if (size < 8 || size >= bfd_get_size (abfd))
return NULL;
if (!bfd_malloc_and_get_section (abfd, sect, & contents))
{
if (contents != NULL)
@ -1280,11 +1292,11 @@ bfd_get_alt_debug_link_info (bfd * abfd, bfd_size_type *buildid_len,
/* BuildID value is stored after the filename. */
name = (char *) contents;
buildid_offset = strnlen (name, bfd_get_section_size (sect)) + 1;
buildid_offset = strnlen (name, size) + 1;
if (buildid_offset >= bfd_get_section_size (sect))
return NULL;
*buildid_len = bfd_get_section_size (sect) - buildid_offset;
*buildid_len = size - buildid_offset;
*buildid_out = bfd_malloc (*buildid_len);
memcpy (*buildid_out, contents + buildid_offset, *buildid_len);