Re: [PATCH] efivarfs: fix NULL-deref on mount when no efivars

[Johan Hovold]

On Thu, Feb 23, 2023 at 05:03:54PM +0800, kernel test robot wrote:
> Hi Johan,
> 
> I love your patch! Yet something to improve:
> 
> [auto build test ERROR on v6.2-rc5]
> [also build test ERROR on linus/master]
> [cannot apply to efi/next next-20230223]

I have no idea what your robot is trying to do here, but this patch has
been folded into 301de9a20553 ("efivarfs: always register filesystem")
and is already in linux-next building just fine.

> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Johan-Hovold/efivarfs-fix-NULL-deref-on-mount-when-no-efivars/20230128-094525
> patch link:    https://lore.kernel.org/r/20230126112129.4602-1-johan%2Blinaro%40kernel.org
> patch subject: [PATCH] efivarfs: fix NULL-deref on mount when no efivars
> config: x86_64-randconfig-a011 (https://download.01.org/0day-ci/archive/20230223/202302231642.tyrVwZMY-lkp@xxxxxxxxx/config)
> compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
> reproduce (this is a W=1 build):
>         # https://github.com/intel-lab-lkp/linux/commit/da57163cc9d947884520240ec71c2806f48b8a64
>         git remote add linux-review https://github.com/intel-lab-lkp/linux
>         git fetch --no-tags linux-review Johan-Hovold/efivarfs-fix-NULL-deref-on-mount-when-no-efivars/20230128-094525
>         git checkout da57163cc9d947884520240ec71c2806f48b8a64
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         make W=1 O=build_dir ARCH=x86_64 olddefconfig
>         make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash fs/
> 
> If you fix the issue, kindly add following tag where applicable
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Link: https://lore.kernel.org/oe-kbuild-all/202302231642.tyrVwZMY-lkp@xxxxxxxxx/
> 
> All errors (new ones prefixed by >>):
> 
>    fs/efivarfs/super.c: In function 'efivarfs_kill_sb':
> >> fs/efivarfs/super.c:246:14: error: implicit declaration of function 'efivar_is_available'; did you mean 'slab_is_available'? [-Werror=implicit-function-declaration]
>      246 |         if (!efivar_is_available())
>          |              ^~~~~~~~~~~~~~~~~~~
>          |              slab_is_available
>    cc1: some warnings being treated as errors
> 
> 
> vim +246 fs/efivarfs/super.c
> 
>    241	
>    242	static void efivarfs_kill_sb(struct super_block *sb)
>    243	{
>    244		kill_litter_super(sb);
>    245	
>  > 246		if (!efivar_is_available())
>    247			return;
>    248	
>    249		/* Remove all entries and destroy */
>    250		efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL);
>    251	}
>    252	

Johan