Hi,

On Tue, Oct 05, 2021 at 05:32:16PM +0200, Jan-Benedict Glaw wrote:
> I'm running automated test compiles on Binutils, GCC, Linux, NetBSD
> and, since a few days ago, elfutils.
> 
> Building/running the tests, I noticed this little warning:
> 
> [make 2021-10-01 12:18:15] elflint.c: In function 'check_sections':
> [make 2021-10-01 12:18:15] elflint.c:4105:48: error: null pointer dereference [-Werror=null-dereference]
> [make 2021-10-01 12:18:15]  4105 |                                  idx < databits->d_size && ! bad;
> [make 2021-10-01 12:18:15]       |                                        ~~~~~~~~^~~~~~~~
> [make 2021-10-01 12:18:18] cc1: all warnings being treated as errors
> [make 2021-10-01 12:18:18] make[2]: *** [Makefile:799: elflint.o] Error 1
> [make 2021-10-01 12:18:18] make[1]: *** [Makefile:532: all-recursive] Error 1
> [make 2021-10-01 12:18:18] make: *** [Makefile:448: all] Error 2
> 
> 
> As it is tested beforehand that we should not run into this, this
> patch should fix the warning:
> 
> 
> diff --git a/src/elflint.c b/src/elflint.c
> index 1ce75684..ef7725ce 100644
> --- a/src/elflint.c
> +++ b/src/elflint.c
> @@ -4102,7 +4102,7 @@ section [%2zu] '%s' has type NOBITS but is read from the file in segment of prog
>  			    bad = (databits == NULL
>  				   || databits->d_size != shdr->sh_size);
>  			    for (size_t idx = 0;
> -				 idx < databits->d_size && ! bad;
> +				 ! bad && idx < databits->d_size;
>  				 idx++)
>  			      bad = ((char *) databits->d_buf)[idx] != 0;
>  

Thanks, that warning and the fix look correct.
I committed the attached fix.

Cheers,

Mark