From 493a33860c71cac998f1a56d6d87d6faa801fbaa Mon Sep 17 00:00:00 2001 From: Nick Clifton Date: Mon, 27 Oct 2014 12:43:16 +0000 Subject: [PATCH] This patch closes a potential security hole in applications that use the bfd library to parse binaries containing maliciously corrupt section group headers. PR binutils/17510 * elf.c (setup_group): Improve handling of corrupt group sections. --- bfd/ChangeLog | 6 ++++++ bfd/elf.c | 34 ++++++++++++++++++++++++++++++---- 2 files changed, 36 insertions(+), 4 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 04b6d86f9b7..7ba4431112b 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,9 @@ +2014-10-27 Nick Clifton + + PR binutils/17510 + * elf.c (setup_group): Improve handling of corrupt group + sections. + 2014-10-24 Tejas Belagod * bfd-in.h (bfd_elf64_aarch64_set_options): Add a parameter. diff --git a/bfd/elf.c b/bfd/elf.c index c884d1d6a93..c8ac826e62b 100644 --- a/bfd/elf.c +++ b/bfd/elf.c @@ -608,9 +608,10 @@ setup_group (bfd *abfd, Elf_Internal_Shdr *hdr, asection *newsect) if (shdr->contents == NULL) { _bfd_error_handler - (_("%B: Corrupt size field in group section header: 0x%lx"), abfd, shdr->sh_size); + (_("%B: corrupt size field in group section header: 0x%lx"), abfd, shdr->sh_size); bfd_set_error (bfd_error_bad_value); - return FALSE; + -- num_group; + continue; } memset (shdr->contents, 0, amt); @@ -618,8 +619,17 @@ setup_group (bfd *abfd, Elf_Internal_Shdr *hdr, asection *newsect) if (bfd_seek (abfd, shdr->sh_offset, SEEK_SET) != 0 || (bfd_bread (shdr->contents, shdr->sh_size, abfd) != shdr->sh_size)) - return FALSE; - + { + _bfd_error_handler + (_("%B: invalid size field in group section header: 0x%lx"), abfd, shdr->sh_size); + bfd_set_error (bfd_error_bad_value); + -- num_group; + /* PR 17510: If the group contents are even partially + corrupt, do not allow any of the contents to be used. */ + memset (shdr->contents, 0, amt); + continue; + } + /* Translate raw contents, a flag word followed by an array of elf section indices all in target byte order, to the flag word followed by an array of elf section @@ -651,6 +661,21 @@ setup_group (bfd *abfd, Elf_Internal_Shdr *hdr, asection *newsect) } } } + + /* PR 17510: Corrupt binaries might contain invalid groups. */ + if (num_group != (unsigned) elf_tdata (abfd)->num_group) + { + elf_tdata (abfd)->num_group = num_group; + + /* If all groups are invalid then fail. */ + if (num_group == 0) + { + elf_tdata (abfd)->group_sect_ptr = NULL; + elf_tdata (abfd)->num_group = num_group = -1; + (*_bfd_error_handler) (_("%B: no valid group sections found"), abfd); + bfd_set_error (bfd_error_bad_value); + } + } } } @@ -716,6 +741,7 @@ setup_group (bfd *abfd, Elf_Internal_Shdr *hdr, asection *newsect) { (*_bfd_error_handler) (_("%B: no group info for section %A"), abfd, newsect); + return FALSE; } return TRUE; } -- 2.30.2