From: Navid Emamdoost <navid.emamdoost@xxxxxxxxx> nla_nest_start may fail and return NULL. The check is inserted, and errno is selected based on other call sites within the same source code. Update: removed extra new line. v3 Update: added release reply, thanks to Michal Kubecek for pointing out. Signed-off-by: Navid Emamdoost <navid.emamdoost@xxxxxxxxx> Reviewed-by: Michal Kubecek <mkubecek@xxxxxxx> Link: https://lore.kernel.org/r/20190911164013.27364-1-navid.emamdoost@xxxxxxxxx/ --- I'm resending the patch because there was apparent consensus of its inclusion and it seems it was only overlooked. Some people may care about this because of CVE-2019-16089. drivers/block/nbd.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 592cfa8b765a..109dccd9a515 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -2394,6 +2394,12 @@ static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info) } dev_list = nla_nest_start_noflag(reply, NBD_ATTR_DEVICE_LIST); + if (!dev_list) { + nlmsg_free(reply); + ret = -EMSGSIZE; + goto out; + } + if (index == -1) { ret = idr_for_each(&nbd_index_idr, &status_cb, reply); if (ret) { -- 2.40.0
