Re: [PATCH -fixes] bpf: resolve_btfids: Fix integer overflow when calling elf_update()

[Jiri Olsa]

On Mon, May 27, 2024 at 05:31:37PM +0200, Alexandre Ghiti wrote:
> The following error was encoutered in [1]:
> 
> FAILED elf_update(WRITE): no error

hi,
this fix got already in, check this patch:
  https://patchwork.kernel.org/project/netdevbpf/patch/20240514070931.199694-1-friedrich.vock@xxxxxx/

thanks,
jirka

> 
> elf_update() returns the total size of the file which here happens to be
> a ~2.5GB vmlinux file: this size overflows the integer used to hold the
> return value of elf_update() and is then interpreted as being negative.
> 
> So fix this by using the correct type expected by elf_update() which is
> off_t.
> 
> Fixes: fbbb68de80a4 ("bpf: Add resolve_btfids tool to resolve BTF IDs in ELF object")
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=218887 [1]
> Signed-off-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
> ---
>  tools/bpf/resolve_btfids/main.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c
> index d9520cb826b3..af393c7dee1f 100644
> --- a/tools/bpf/resolve_btfids/main.c
> +++ b/tools/bpf/resolve_btfids/main.c
> @@ -728,7 +728,7 @@ static int sets_patch(struct object *obj)
>  
>  static int symbols_patch(struct object *obj)
>  {
> -	int err;
> +	off_t err;
>  
>  	if (__symbols_patch(obj, &obj->structs)  ||
>  	    __symbols_patch(obj, &obj->unions)   ||
> -- 
> 2.39.2
>