Fix illegal memory access parsing a corrupt ELF file.

PR 24332
	* elflink.c (elf_link_add_object_symbols): Add new local variable
	extversym_end.  Initialise it to point to the end of the version
	symbol table, if present.  Check it when initialising and updating
	the ever pointer.
This commit is contained in:
Nick Clifton 2019-03-14 14:45:32 +00:00
parent 3b336828de
commit be22c732bf
2 changed files with 34 additions and 3 deletions

View file

@ -1,3 +1,11 @@
2019-03-14 Nick Clifton <nickc@redhat.com>
PR 24332
* elflink.c (elf_link_add_object_symbols): Add new local variable
extversym_end. Initialise it to point to the end of the version
symbol table, if present. Check it when initialising and updating
the ever pointer.
2019-03-13 Sudakshina Das <sudi.das@arm.com>
* elfnn-aarch64.c (PLT_PAC_ENTRY_SIZE, PLT_PAC_SMALL_ENTRY_SIZE): New.

View file

@ -3872,6 +3872,7 @@ elf_link_add_object_symbols (bfd *abfd, struct bfd_link_info *info)
struct elf_link_hash_entry **sym_hash;
bfd_boolean dynamic;
Elf_External_Versym *extversym = NULL;
Elf_External_Versym *extversym_end = NULL;
Elf_External_Versym *ever;
struct elf_link_hash_entry *weaks;
struct elf_link_hash_entry **nondeflt_vers = NULL;
@ -4297,13 +4298,14 @@ error_free_dyn:
Elf_Internal_Shdr *versymhdr;
versymhdr = &elf_tdata (abfd)->dynversym_hdr;
extversym = (Elf_External_Versym *) bfd_malloc (versymhdr->sh_size);
amt = versymhdr->sh_size;
extversym = (Elf_External_Versym *) bfd_malloc (amt);
if (extversym == NULL)
goto error_free_sym;
amt = versymhdr->sh_size;
if (bfd_seek (abfd, versymhdr->sh_offset, SEEK_SET) != 0
|| bfd_bread (extversym, amt, abfd) != amt)
goto error_free_vers;
extversym_end = extversym + (amt / sizeof (* extversym));
}
}
@ -4378,7 +4380,20 @@ error_free_dyn:
}
weaks = NULL;
ever = extversym != NULL ? extversym + extsymoff : NULL;
if (extversym == NULL)
ever = NULL;
else if (extversym + extsymoff < extversym_end)
ever = extversym + extsymoff;
else
{
/* xgettext:c-format */
_bfd_error_handler (_("%pB: invalid version offset %lx (max %lx)"),
abfd, (long) extsymoff,
(long) (extversym_end - extversym) / sizeof (* extversym));
bfd_set_error (bfd_error_bad_value);
goto error_free_vers;
}
for (isym = isymbuf, isymend = isymbuf + extsymcount;
isym < isymend;
isym++, sym_hash++, ever = (ever != NULL ? ever + 1 : NULL))
@ -4562,6 +4577,14 @@ error_free_dyn:
else
iver.vs_vers = 0;
}
else if (ever >= extversym_end)
{
/* xgettext:c-format */
_bfd_error_handler (_("%pB: not enough version information"),
abfd);
bfd_set_error (bfd_error_bad_value);
goto error_free_vers;
}
else
_bfd_elf_swap_versym_in (abfd, ever, &iver);