[PATCH] lto-wrapper: fix memory corruption.

[Richard Biener]

On Wed, Nov 10, 2021 at 11:47 AM Martin Liška <mliska@suse.cz> wrote:
>
> Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
>
> Ready to be installed?

OK.

Is this also latent on branches?


> The first argument of merge_and_complain is actually vector where
> we merge options and it should be propagated to caller properly.
>
> Fixes:
>
> ==6656== Invalid read of size 8
> ==6656==    at 0x408056: merge_and_complain (lto-wrapper.c:335)
> ==6656==    by 0x408056: find_and_merge_options(int, long, char const*, vec<cl_decoded_option, va_heap, vl_ptr>, vec<cl_decoded_option, va_heap, vl_ptr>*, char const*) (lto-wrapper.c:1139)
> ==6656==    by 0x408AFC: run_gcc(unsigned int, char**) (lto-wrapper.c:1505)
> ==6656==    by 0x4061A2: main (lto-wrapper.c:2138)
> ==6656==  Address 0x4e69b18 is 344 bytes inside a block of size 1,768 free'd
> ==6656==    at 0x484339F: realloc (vg_replace_malloc.c:1192)
> ==6656==    by 0x4993C0: xrealloc (xmalloc.c:181)
> ==6656==    by 0x406A82: reserve<cl_decoded_option> (vec.h:290)
> ==6656==    by 0x406A82: reserve (vec.h:1858)
> ==6656==    by 0x406A82: vec<cl_decoded_option, va_heap, vl_ptr>::safe_push(cl_decoded_option const&) [clone .isra.0] (vec.h:1967)
> ==6656==    by 0x4077E0: merge_and_complain (lto-wrapper.c:457)
> ==6656==    by 0x4077E0: find_and_merge_options(int, long, char const*, vec<cl_decoded_option, va_heap, vl_ptr>, vec<cl_decoded_option, va_heap, vl_ptr>*, char const*) (lto-wrapper.c:1139)
> ==6656==    by 0x408AFC: run_gcc(unsigned int, char**) (lto-wrapper.c:1505)
> ==6656==    by 0x4061A2: main (lto-wrapper.c:2138)
> ==6656==  Block was alloc'd at
> ==6656==    at 0x483E70F: malloc (vg_replace_malloc.c:380)
> ==6656==    by 0x4993D7: xrealloc (xmalloc.c:179)
> ==6656==    by 0x407476: reserve<cl_decoded_option> (vec.h:290)
> ==6656==    by 0x407476: reserve (vec.h:1858)
> ==6656==    by 0x407476: reserve_exact (vec.h:1878)
> ==6656==    by 0x407476: create (vec.h:1893)
> ==6656==    by 0x407476: get_options_from_collect_gcc_options(char const*, char const*) (lto-wrapper.c:163)
> ==6656==    by 0x407674: find_and_merge_options(int, long, char const*, vec<cl_decoded_option, va_heap, vl_ptr>, vec<cl_decoded_option, va_heap, vl_ptr>*, char const*) (lto-wrapper.c:1132)
> ==6656==    by 0x408AFC: run_gcc(unsigned int, char**) (lto-wrapper.c:1505)
> ==6656==    by 0x4061A2: main (lto-wrapper.c:2138)
>
> gcc/ChangeLog:
>
>         * lto-wrapper.c (merge_and_complain): Make the first argument
>         a reference type.
> ---
>   gcc/lto-wrapper.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/gcc/lto-wrapper.c b/gcc/lto-wrapper.c
> index 7b9e4883f38..54f642d7692 100644
> --- a/gcc/lto-wrapper.c
> +++ b/gcc/lto-wrapper.c
> @@ -224,7 +224,7 @@ merge_flto_options (vec<cl_decoded_option> &decoded_options,
>      ontop of DECODED_OPTIONS.  */
>
>   static void
> -merge_and_complain (vec<cl_decoded_option> decoded_options,
> +merge_and_complain (vec<cl_decoded_option> &decoded_options,
>                     vec<cl_decoded_option> fdecoded_options,
>                     vec<cl_decoded_option> decoded_cl_options)
>   {
> --
> 2.33.1
>