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Re: [PATCH v2] libiberty: Check zero value shstrndx in simple-object-elf.c


Oh. I missed a ChangeLog entry.
Hold on... I'll send v3 patch.

Thanks

2019年7月12日(金) 19:37 Ren Kimura <rkx1209dev@gmail.com>:
>
> This patch fixes a Bug 90924.
> simple_object_elf functions don't load section table 0 of ELF file, which is not a useful.
> However If e_shstrndx in ELF header points to a section table 0 (i.e. e_shstrndx == 0), a calculation of offset to string section table causes integer overflow at every line "(eor->shstrndx - 1)".
> A result becomes negative value (unsigned int)-1 and causes memory corruption.
>
> Signed-off-by: Ren Kimura <rkx1209dev@gmail.com>
> ---
>  libiberty/simple-object-elf.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/libiberty/simple-object-elf.c b/libiberty/simple-object-elf.c
> index 22c9ae7ed2d..9c561632bc5 100644
> --- a/libiberty/simple-object-elf.c
> +++ b/libiberty/simple-object-elf.c
> @@ -548,7 +548,15 @@ simple_object_elf_match (unsigned char header[SIMPLE_OBJECT_MATCH_HEADER_LEN],
>        XDELETE (eor);
>        return NULL;
>      }
> -
> +
> +  if (eor->shstrndx == 0)
> +    {
> +      *errmsg = "invalid ELF shstrndx == 0";
> +      *err = 0;
> +      XDELETE (eor);
> +      return NULL;
> +    }
> +
>    return (void *) eor;
>  }
>
> --
> 2.19.1
>


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