Re: [PATCH] module: fix lost error code from codetag_load_module()

[Suren Baghdasaryan]

On Wed, Aug 26, 2026 at 2:24 AM Petr Pavlu <petr.pavlu@xxxxxxxx> wrote:
>
> On 8/24/26 3:47 AM, Hao Ge wrote:
> > If codetag_load_module() fails, err is never set and load_module()
> > returns 0 after the module has been torn down.
> >
> > Fixes: 044d2aee6c57 ("alloc_tag: handle module codetag load errors as module load failures")
> > Reported-by: Sashiko <sashiko-bot@xxxxxxxxxx>
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Hao Ge <hao.ge@xxxxxxxxx>
> > ---
> >  kernel/module/main.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/kernel/module/main.c b/kernel/module/main.c
> > index 46dd8d25a605..afb810f0154c 100644
> > --- a/kernel/module/main.c
> > +++ b/kernel/module/main.c
> > @@ -3568,7 +3568,8 @@ static int load_module(struct load_info *info, const char __user *uargs,
> >                       goto sysfs_cleanup;
> >       }
> >
> > -     if (codetag_load_module(mod))
> > +     err = codetag_load_module(mod);
> > +     if (err)
> >               goto sysfs_cleanup;
> >
> >       /* Get rid of temporary copy. */
>
> This looks ok to me but there appears another bug related to this code
> that would be good to fix at the same time. If the module is
> a livepatch, the preceding call to copy_module_elf() allocates
> mod->klp_info. However, if codetag_load_module() fails, the code doesn't
> free it.

Ah, I see. Nice catch!

>
> I think we want something like this (not tested):

Yep, that looks like the right fix to me. Thanks!

>
> diff --git a/kernel/module/main.c b/kernel/module/main.c
> index d0e1e0bd2ad0..c1b34dc1e89a 100644
> --- a/kernel/module/main.c
> +++ b/kernel/module/main.c
> @@ -3581,8 +3581,9 @@ static int load_module(struct load_info *info, const char __user *uargs,
>                         goto sysfs_cleanup;
>         }
>
> -       if (codetag_load_module(mod))
> -               goto sysfs_cleanup;
> +       err = codetag_load_module(mod);
> +       if (err)
> +               goto livepatch_cleanup;
>
>         /* Get rid of temporary copy. */
>         free_copy(info, flags);
> @@ -3592,6 +3593,9 @@ static int load_module(struct load_info *info, const char __user *uargs,
>
>         return do_init_module(mod);
>
> + livepatch_cleanup:
> +       if (is_livepatch_module(mod))
> +               free_module_elf(mod);
>   sysfs_cleanup:
>         mod_sysfs_teardown(mod);
>   coming_cleanup:
>
> --
> Thanks,
> Petr