Re: [PATCH v4 15/22] scripts/sortextable: add support for ET_DYN binaries

From: Kees Cook
Date: Tue Jan 26 2016 - 18:25:58 EST


On Tue, Jan 26, 2016 at 9:10 AM, Ard Biesheuvel
<ard.biesheuvel@xxxxxxxxxx> wrote:
> Add support to scripts/sortextable for handling relocatable (PIE)
> executables, whose ELF type is ET_DYN, not ET_EXEC. Other than adding
> support for the new type, no changes are needed.
>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

Something I can actually test! :)

-Kees

> ---
> scripts/sortextable.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/scripts/sortextable.c b/scripts/sortextable.c
> index af247c70fb66..19d83647846c 100644
> --- a/scripts/sortextable.c
> +++ b/scripts/sortextable.c
> @@ -266,9 +266,9 @@ do_file(char const *const fname)
> break;
> } /* end switch */
> if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
> - || r2(&ehdr->e_type) != ET_EXEC
> + || (r2(&ehdr->e_type) != ET_EXEC && r2(&ehdr->e_type) != ET_DYN)
> || ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
> - fprintf(stderr, "unrecognized ET_EXEC file %s\n", fname);
> + fprintf(stderr, "unrecognized ET_EXEC/ET_DYN file %s\n", fname);
> fail_file();
> }
>
> @@ -304,7 +304,7 @@ do_file(char const *const fname)
> if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
> || r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
> fprintf(stderr,
> - "unrecognized ET_EXEC file: %s\n", fname);
> + "unrecognized ET_EXEC/ET_DYN file: %s\n", fname);
> fail_file();
> }
> do32(ehdr, fname, custom_sort);
> @@ -314,7 +314,7 @@ do_file(char const *const fname)
> if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
> || r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
> fprintf(stderr,
> - "unrecognized ET_EXEC file: %s\n", fname);
> + "unrecognized ET_EXEC/ET_DYN file: %s\n", fname);
> fail_file();
> }
> do64(ghdr, fname, custom_sort);
> --
> 2.5.0
>



--
Kees Cook
Chrome OS & Brillo Security