[dm-devel] [PATCH] libmultipath: snprint_devices(): avoid NULL dereference

[Benjamin Marzinski]

On Mon, Jan 25, 2021 at 04:23:04PM +0100, mwilck at suse.com wrote:
> From: Martin Wilck <mwilck at suse.com>
> 
> All libudev functions may return NULL. Watch out for it.
> 
> Fixes: d041258 ("libmultipath: snprint_devices(): use udev_enumerate"
> Signed-off-by: Martin Wilck <mwilck at suse.com>
Reviewed-by: Benjamin Marzinski <bmarzins at redhat.com>
> ---
>  libmultipath/print.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/libmultipath/print.c b/libmultipath/print.c
> index 19de2c7..8151e11 100644
> --- a/libmultipath/print.c
> +++ b/libmultipath/print.c
> @@ -2055,8 +2055,16 @@ int snprint_devices(struct config *conf, char *buff, size_t len,
>  		struct udev_device *u_dev;
>  
>  		path = udev_list_entry_get_name(item);
> +		if (!path)
> +			continue;
>  		u_dev = udev_device_new_from_syspath(udev, path);
> +		if (!u_dev)
> +			continue;
>  		devname = udev_device_get_sysname(u_dev);
> +		if (!devname) {
> +			udev_device_unref(u_dev);
> +			continue;
> +		}
>  
>  		fwd += snprintf(buff + fwd, len - fwd, "    %s", devname);
>  		if (fwd >= len)
> -- 
> 2.29.2