Bug#891773: [PATCH] ieee1275: Fix crash in of_path_of_nvme when of_path is empty

[Eric Snowberg]

> On Mar 1, 2018, at 3:34 PM, John Paul Adrian Glaubitz <glaubitz at physik.fu-berlin.de> wrote:
> 
> The of_path_of_nvme function (commit 2391d57, ieee1275: add nvme
> support within ofpath) introduced a functional regression:
> 
> On systems which are not based on Open Firmware but have at
> least one NVME device, find_obppath will return NULL and thus
> trying to append the disk name to of_path will result in a
> crash.
> 
> The proper behavior of of_path_of_nvme is, however, to just
> return NULL in such cases, like other users of find_obppath,
> such as of_path_of_scsi.
> 
> Signed-off-by: John Paul Adrian Glaubitz <glaubitz at physik.fu-berlin.de>
> ---
> grub-core/osdep/linux/ofpath.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/grub-core/osdep/linux/ofpath.c b/grub-core/osdep/linux/ofpath.c
> index 1c30e7233..61806212e 100644
> --- a/grub-core/osdep/linux/ofpath.c
> +++ b/grub-core/osdep/linux/ofpath.c
> @@ -389,8 +389,11 @@ of_path_of_nvme(const char *sys_devname __attribute__((unused)),
>     }
> 
>   of_path = find_obppath (sysfs_path);
> +
> +  if (of_path)
> +    strcat (of_path, disk);
> +
>   free (sysfs_path);
> -  strcat (of_path, disk);
>   return of_path;
> }
> 
> -- 
> 2.16.2

Reviewed-by: Eric Snowberg <eric.snowberg at oracle.com>