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| author | Alan Modra <amodra@gmail.com> | 2014-09-12 09:35:42 +0930 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2014-09-12 09:44:09 +0930 |
| commit | ae6c7e33e1510665e8e043eb11a71e59414efbf3 (patch) | |
| tree | 505b0c39d85f07f8e385cb8d4f51846a94ce6ec3 /bfd/elf-eh-frame.c | |
| parent | 18d60c2bd70855afa467f0d5d8f95b3e4d243cde (diff) | |
| download | gdb-ae6c7e33e1510665e8e043eb11a71e59414efbf3.zip gdb-ae6c7e33e1510665e8e043eb11a71e59414efbf3.tar.gz gdb-ae6c7e33e1510665e8e043eb11a71e59414efbf3.tar.bz2 | |
Test for overflow in eh_frame_hdr entries and for overlapping FDEs
With larger binaries on 64-bit systems, or indeed just binaries that
have a large gap between text and data, it is possible for the
.eh_frame_hdr lookup table entry values to overflow a signed 32-bit
relative offset. It is also a requirement for the glibc FDE lookup
code that only one FDE claim to cover any given address.
* elf-bfd.h (struct eh_frame_array_ent): Add "range".
* elf-eh-frame.c (_bfd_elf_write_section_eh_frame): Stash address
range of FDEs to hdr_info->array.
(_bfd_elf_write_section_eh_frame_hdr): Report overflow in
.eh_frame_hdr entries, and overlapping FDEs.
Diffstat (limited to 'bfd/elf-eh-frame.c')
| -rw-r--r-- | bfd/elf-eh-frame.c | 51 |
1 files changed, 41 insertions, 10 deletions
diff --git a/bfd/elf-eh-frame.c b/bfd/elf-eh-frame.c index d56440c..02f2d23 100644 --- a/bfd/elf-eh-frame.c +++ b/bfd/elf-eh-frame.c @@ -1632,6 +1632,8 @@ _bfd_elf_write_section_eh_frame (bfd *abfd, if (sizeof (address) > 4 && ptr_size == 4) address &= 0xffffffff; hdr_info->array[hdr_info->array_count].initial_loc = address; + hdr_info->array[hdr_info->array_count].range + = read_value (abfd, buf + width, width, FALSE); hdr_info->array[hdr_info->array_count++].fde = (sec->output_section->vma + sec->output_offset @@ -1805,26 +1807,55 @@ _bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info) if (contents[2] != DW_EH_PE_omit) { unsigned int i; + bfd_boolean overlap, overflow; bfd_put_32 (abfd, hdr_info->fde_count, contents + EH_FRAME_HDR_SIZE); qsort (hdr_info->array, hdr_info->fde_count, sizeof (*hdr_info->array), vma_compare); + overlap = FALSE; + overflow = FALSE; for (i = 0; i < hdr_info->fde_count; i++) { - bfd_put_32 (abfd, - hdr_info->array[i].initial_loc - - sec->output_section->vma, - contents + EH_FRAME_HDR_SIZE + i * 8 + 4); - bfd_put_32 (abfd, - hdr_info->array[i].fde - sec->output_section->vma, - contents + EH_FRAME_HDR_SIZE + i * 8 + 8); + bfd_vma val; + + val = hdr_info->array[i].initial_loc - sec->output_section->vma; + val = ((val & 0xffffffff) ^ 0x80000000) - 0x80000000; + if (elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64 + && (hdr_info->array[i].initial_loc + != sec->output_section->vma + val)) + overflow = TRUE; + bfd_put_32 (abfd, val, contents + EH_FRAME_HDR_SIZE + i * 8 + 4); + val = hdr_info->array[i].fde - sec->output_section->vma; + val = ((val & 0xffffffff) ^ 0x80000000) - 0x80000000; + if (elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64 + && (hdr_info->array[i].fde + != sec->output_section->vma + val)) + overflow = TRUE; + bfd_put_32 (abfd, val, contents + EH_FRAME_HDR_SIZE + i * 8 + 8); + if (i != 0 + && (hdr_info->array[i].initial_loc + < (hdr_info->array[i - 1].initial_loc + + hdr_info->array[i - 1].range))) + overlap = TRUE; + } + if (overflow) + (*info->callbacks->einfo) + (_("%P: .eh_frame_hdr entry overflow.\n")); + if (overlap) + (*info->callbacks->einfo) + (_("%P: .eh_frame_hdr refers to overlapping FDEs.\n")); + if (overflow || overlap) + { + bfd_set_error (bfd_error_bad_value); + retval = FALSE; } } /* FIXME: octets_per_byte. */ - retval = bfd_set_section_contents (abfd, sec->output_section, contents, - (file_ptr) sec->output_offset, - sec->size); + if (!bfd_set_section_contents (abfd, sec->output_section, contents, + (file_ptr) sec->output_offset, + sec->size)) + retval = FALSE; free (contents); } if (hdr_info->array != NULL) |