From b899eb3bb807be1094fde9a2f1c8628232bc0743 Mon Sep 17 00:00:00 2001 From: Nick Clifton Date: Thu, 9 Jan 2020 15:49:08 +0000 Subject: [PATCH] Fix an illegal memory access triggered when trying to examine an input file containing corrupt compressed sections. PR 25221 * bfd.c (bfd_convert_section_contents): Check for a compress header size that is larger than the actual section size. --- bfd/ChangeLog | 6 ++++++ bfd/bfd.c | 16 ++++++++++++++-- 2 files changed, 20 insertions(+), 2 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 306f2e6512..aae0832e3d 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,9 @@ +2020-01-09 Nick Clifton + + PR 25221 + * bfd.c (bfd_convert_section_contents): Check for a compress + header size that is larger than the actual section size. + 2020-01-08 Alan Modra PR 25351 diff --git a/bfd/bfd.c b/bfd/bfd.c index d590e0a4e9..b1050626b6 100644 --- a/bfd/bfd.c +++ b/bfd/bfd.c @@ -2768,7 +2768,7 @@ bfd_convert_section_contents (bfd *ibfd, sec_ptr isec, bfd *obfd, || bfd_get_flavour (obfd) != bfd_target_elf_flavour) return TRUE; - /* Do nothing if ELF classes of input and output are the same. */ + /* Do nothing if ELF classes of input and output are the same. */ if (get_elf_backend_data (ibfd)->s->elfclass == get_elf_backend_data (obfd)->s->elfclass) return TRUE; @@ -2782,11 +2782,17 @@ bfd_convert_section_contents (bfd *ibfd, sec_ptr isec, bfd *obfd, if ((ibfd->flags & BFD_DECOMPRESS)) return TRUE; - /* Do nothing if the input section isn't a SHF_COMPRESSED section. */ + /* Do nothing if the input section isn't a SHF_COMPRESSED section. */ ihdr_size = bfd_get_compression_header_size (ibfd, isec); if (ihdr_size == 0) return TRUE; + /* PR 25221. Check for corrupt input sections. */ + if (ihdr_size > bfd_get_section_limit (ibfd, isec)) + /* FIXME: Issue a warning about a corrupt + compression header size field ? */ + return FALSE; + contents = *ptr; /* Convert the contents of the input SHF_COMPRESSED section to @@ -2803,6 +2809,12 @@ bfd_convert_section_contents (bfd *ibfd, sec_ptr isec, bfd *obfd, use_memmove = FALSE; } + else if (ihdr_size != sizeof (Elf64_External_Chdr)) + { + /* FIXME: Issue a warning about a corrupt + compression header size field ? */ + return FALSE; + } else { Elf64_External_Chdr *echdr = (Elf64_External_Chdr *) contents; -- 2.34.1