# DP: Fix PR binutils/21137, readelf writing to illegal addresses. From 03f7786e2f440b9892b1c34a58fb26222ce1b493 Mon Sep 17 00:00:00 2001 From: Nick Clifton Date: Mon, 13 Feb 2017 13:08:32 +0000 Subject: [PATCH] Fix readelf writing to illegal addresses whilst processing corrupt input files containing symbol-difference relocations. PR binutils/21137 * readelf.c (target_specific_reloc_handling): Add end parameter. Check for buffer overflow before writing relocated values. (apply_relocations): Pass end to target_specific_reloc_handling. --- binutils/ChangeLog | 7 +++++++ binutils/readelf.c | 30 +++++++++++++++++++++++++----- 2 files changed, 32 insertions(+), 5 deletions(-) 2017-02-13 Nick Clifton PR binutils/21137 * readelf.c (target_specific_reloc_handling): Add end parameter. Check for buffer overflow before writing relocated values. (apply_relocations): Pass end to target_specific_reloc_handling. diff --git a/binutils/readelf.c b/binutils/readelf.c index b488714..e474f27 100644 --- a/binutils/readelf.c +++ b/binutils/readelf.c @@ -11591,6 +11591,7 @@ process_syminfo (FILE * file ATTRIBUTE_UNUSED) static bfd_boolean target_specific_reloc_handling (Elf_Internal_Rela * reloc, unsigned char * start, + unsigned char * end, Elf_Internal_Sym * symtab) { unsigned int reloc_type = get_reloc_type (reloc->r_info); @@ -11631,13 +11632,19 @@ target_specific_reloc_handling (Elf_Internal_Rela * reloc, handle_sym_diff: if (saved_sym != NULL) { + int reloc_size = reloc_type == 1 ? 4 : 2; bfd_vma value; value = reloc->r_addend + (symtab[get_reloc_symindex (reloc->r_info)].st_value - saved_sym->st_value); - byte_put (start + reloc->r_offset, value, reloc_type == 1 ? 4 : 2); + if (start + reloc->r_offset + reloc_size >= end) + /* PR 21137 */ + error (_("MSP430 sym diff reloc writes past end of section (%p vs %p)\n"), + start + reloc->r_offset + reloc_size, end); + else + byte_put (start + reloc->r_offset, value, reloc_size); saved_sym = NULL; return TRUE; @@ -11668,13 +11675,18 @@ target_specific_reloc_handling (Elf_Internal_Rela * reloc, case 2: /* R_MN10300_16 */ if (saved_sym != NULL) { + int reloc_size = reloc_type == 1 ? 4 : 2; bfd_vma value; value = reloc->r_addend + (symtab[get_reloc_symindex (reloc->r_info)].st_value - saved_sym->st_value); - byte_put (start + reloc->r_offset, value, reloc_type == 1 ? 4 : 2); + if (start + reloc->r_offset + reloc_size >= end) + error (_("MN10300 sym diff reloc writes past end of section (%p vs %p)\n"), + start + reloc->r_offset + reloc_size, end); + else + byte_put (start + reloc->r_offset, value, reloc_size); saved_sym = NULL; return TRUE; @@ -11709,12 +11721,20 @@ target_specific_reloc_handling (Elf_Internal_Rela * reloc, break; case 0x41: /* R_RL78_ABS32. */ - byte_put (start + reloc->r_offset, value, 4); + if (start + reloc->r_offset + 4 >= end) + error (_("RL78 sym diff reloc writes past end of section (%p vs %p)\n"), + start + reloc->r_offset + 2, end); + else + byte_put (start + reloc->r_offset, value, 4); value = 0; return TRUE; case 0x43: /* R_RL78_ABS16. */ - byte_put (start + reloc->r_offset, value, 2); + if (start + reloc->r_offset + 2 >= end) + error (_("RL78 sym diff reloc writes past end of section (%p vs %p)\n"), + start + reloc->r_offset + 2, end); + else + byte_put (start + reloc->r_offset, value, 2); value = 0; return TRUE; @@ -12340,7 +12360,7 @@ apply_relocations (void * file, reloc_type = get_reloc_type (rp->r_info); - if (target_specific_reloc_handling (rp, start, symtab)) + if (target_specific_reloc_handling (rp, start, end, symtab)) continue; else if (is_none_reloc (reloc_type)) continue; -- 2.9.3