Hi Maks,
On Fri, Apr 05, 2024 at 09:53:03PM +0300, Maks Mishin wrote:
> Return value of a function 'elf_begin' is dereferenced at strip.c:1166
> without checking for NULL, but it is usually checked for this function.
Please stop sending these "patches" till you actually understand the
code.
In this case if debugelf == NULL then gelf_newehdr will also return
NULL to indicate the earlier error.
This is a common pattern in the libelf code.
Thanks,
Mark
> Found by RASU JSC.
>
> Signed-off-by: Maks Mishin <maks.mishi...@gmail.com>
> ---
> src/strip.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/src/strip.c b/src/strip.c
> index 6436443d..ebab4866 100644
> --- a/src/strip.c
> +++ b/src/strip.c
> @@ -1153,7 +1153,9 @@ handle_elf (int fd, Elf *elf, const char *prefix, const
> char *fname,
> {
> /* Also create an ELF descriptor for the debug file */
> debugelf = elf_begin (debug_fd, ELF_C_WRITE, NULL);
> - if (unlikely (gelf_newehdr (debugelf, gelf_getclass (elf)) == 0))
> + ELF_CHECK (debugelf != NULL, _("cannot create ELF descriptor: %s"));
> +
> + if (unlikely (gelf_newehdr (debugelf, gelf_getclass (elf)) == 0))
> {
> error (0, 0, _("cannot create new ehdr for file '%s': %s"),
> debug_fname, elf_errmsg (-1));
> --
> 2.30.2
>
