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[PATCH] readelf robustification (part N)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: binutils at sources dot redhat dot com
- Date: Tue, 14 Jun 2005 15:07:01 +0200
- Subject: [PATCH] readelf robustification (part N)
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
The endless patchset continues.
This patch prevents crashes if readelf is run on objects with
bogus sh_entsize.
2005-06-14 Jakub Jelinek <jakub@redhat.com>
* readelf.c (CHECK_ENTSIZE_VALUES, CHECK_ENTSIZE): Define.
(process_section_headers): Use it.
(process_relocs): Don't crash if symsec is not SHT_SYMTAB
or SHT_DYNSYM.
(process_version_sections): Use 2 instead of sh_entsize.
--- binutils/readelf.c.jj 2005-06-14 12:36:32.000000000 +0200
+++ binutils/readelf.c 2005-06-14 14:06:58.000000000 +0200
@@ -3871,6 +3871,20 @@ process_section_headers (FILE *file)
break;
}
+#define CHECK_ENTSIZE_VALUES(section, i, size32, size64) \
+ do { \
+ size_t expected_entsize \
+ = is_32bit_elf ? size32 : size64; \
+ if (section->sh_entsize != expected_entsize) \
+ error (_("Section %d has invalid sh_entsize %lx (expected %lx)\n"), \
+ i, (unsigned long int) section->sh_entsize, \
+ (unsigned long int) expected_entsize); \
+ section->sh_entsize = expected_entsize; \
+ } while (0)
+#define CHECK_ENTSIZE(section, i, type) \
+ CHECK_ENTSIZE_VALUES (section, i, sizeof (Elf32_External_##type), \
+ sizeof (Elf64_External_##type))
+
for (i = 0, section = section_headers;
i < elf_header.e_shnum;
i++, section++)
@@ -3885,6 +3899,7 @@ process_section_headers (FILE *file)
continue;
}
+ CHECK_ENTSIZE (section, i, Sym);
num_dynamic_syms = section->sh_size / section->sh_entsize;
dynamic_symbols = GET_ELF_SYMBOLS (file, section);
}
@@ -3910,6 +3925,14 @@ process_section_headers (FILE *file)
}
symtab_shndx_hdr = section;
}
+ else if (section->sh_type == SHT_SYMTAB)
+ CHECK_ENTSIZE (section, i, Sym);
+ else if (section->sh_type == SHT_GROUP)
+ CHECK_ENTSIZE_VALUES (section, i, 4, 4);
+ else if (section->sh_type == SHT_REL)
+ CHECK_ENTSIZE (section, i, Rel);
+ else if (section->sh_type == SHT_RELA)
+ CHECK_ENTSIZE (section, i, Rela);
else if ((do_debugging || do_debug_info || do_debug_abbrevs
|| do_debug_lines || do_debug_pubnames || do_debug_aranges
|| do_debug_frames || do_debug_macinfo || do_debug_str
@@ -4488,6 +4511,10 @@ process_relocs (FILE *file)
char *strtab = NULL;
symsec = SECTION_HEADER (section->sh_link);
+ if (symsec->sh_type != SHT_SYMTAB
+ && symsec->sh_type != SHT_DYNSYM)
+ continue;
+
nsyms = symsec->sh_size / symsec->sh_entsize;
symtab = GET_ELF_SYMBOLS (file, symsec);
@@ -6358,7 +6385,7 @@ process_version_sections (FILE *file)
break;
link_section = SECTION_HEADER (section->sh_link);
- total = section->sh_size / section->sh_entsize;
+ total = section->sh_size / 2;
if (SECTION_HEADER_INDEX (link_section->sh_link)
>= elf_header.e_shnum)
Jakub