From: Navid Emamdoost <navid.emamdoost@gmail.com>
Date: Sun, 18 Feb 2024 04:25:38 +0000 (-0800)
Subject: nbd: null check for nla_nest_start
X-Git-Tag: v5.10.214~204
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=4af837db0fd3679fabc7b7758397090b0c06dced;p=thirdparty%2Fkernel%2Fstable.git

nbd: null check for nla_nest_start

[ Upstream commit 31edf4bbe0ba27fd03ac7d87eb2ee3d2a231af6d ]

nla_nest_start() may fail and return NULL. Insert a check and set errno
based on other call sites within the same source code.

Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Fixes: 47d902b90a32 ("nbd: add a status netlink command")
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240218042534.it.206-kees@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index e0f805ca0e727..d6e3edb404748 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -2339,6 +2339,12 @@ 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) {