[PATCH] D25327: [ELF] - Do not crash on invalid size of dynamic section.

[Rafael Espíndola via llvm-commits]

On 6 October 2016 at 11:09, George Rimar <grimar at accesssoftek.com> wrote:
> grimar created this revision.
> grimar added reviewers: ruiu, rafael, davide.
> grimar added subscribers: llvm-commits, grimar, evgeny777.
>
> Previously if sh_size of dynamic section was broken,
> lld may crash. Or even may not crash if used 32 bits host.
> (then value may be truncated to 32 bits when doing pointer arithmetic
> and could be just zero).
> Patch fixes the issue.
>
>
> https://reviews.llvm.org/D25327
>
> Files:
>   ELF/InputFiles.cpp
>   test/ELF/invalid/Inputs/dynamic-section-sh_size.elf
>   test/ELF/invalid/dynamic-section-size.s
>
>
> Index: test/ELF/invalid/dynamic-section-size.s
> ===================================================================
> --- test/ELF/invalid/dynamic-section-size.s
> +++ test/ELF/invalid/dynamic-section-size.s
> @@ -0,0 +1,4 @@
> +## dynamic-section-sh_size.elf has incorrect sh_size of dynamic section.
> +# RUN: not ld.lld %p/Inputs/dynamic-section-sh_size.elf -o %t2 2>&1 | \
> +# RUN:   FileCheck %s
> +# CHECK: Invalid data was encountered while parsing the file
> Index: ELF/InputFiles.cpp
> ===================================================================
> --- ELF/InputFiles.cpp
> +++ ELF/InputFiles.cpp
> @@ -518,11 +518,11 @@
>
>    if (!DynamicSec)
>      return;
> -  auto *Begin =
> -      reinterpret_cast<const Elf_Dyn *>(Obj.base() + DynamicSec->sh_offset);
> -  const Elf_Dyn *End = Begin + DynamicSec->sh_size / sizeof(Elf_Dyn);
>
> -  for (const Elf_Dyn &Dyn : make_range(Begin, End)) {
> +  ArrayRef<Elf_Dyn> Arr =
> +      check(Obj.template getSectionContentsAsArray<Elf_Dyn>(DynamicSec),
> +            getFilename(this));
> +  for (const Elf_Dyn &Dyn : Ar

Test for the filename in the test since you are including it in the error.

LGTM with that.

Cheers,
Rafael