2024-02-18 04:25:55

by Kees Cook

Subject: [PATCH v4] nbd: null check for nla_nest_start

From: Navid Emamdoost <[email protected]>

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 <[email protected]>
Reviewed-by: Michal Kubecek <[email protected]>
Fixes: 47d902b90a32 ("nbd: add a status netlink command")
Signed-off-by: Kees Cook <[email protected]>
---
v3- https://lore.kernel.org/lkml/[email protected]/
Resending on behalf of the author. This seems to have gotten lost and
has been getting tracked as CVE-2019-16089 ever since. For example:
https://ubuntu.com/security/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 33a8f37bb6a1..b7c332528ed7 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -2433,6 +2433,12 @@ 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) {
--
2.34.1

2024-02-18 13:02:07

by Jens Axboe

Subject: Re: [PATCH v4] nbd: null check for nla_nest_start

On Sat, 17 Feb 2024 20:25:38 -0800, Kees Cook wrote:
> nla_nest_start() may fail and return NULL. Insert a check and set errno
> based on other call sites within the same source code.
>
>

Applied, thanks!

[1/1] nbd: null check for nla_nest_start
commit: 31edf4bbe0ba27fd03ac7d87eb2ee3d2a231af6d

Best regards,
--
Jens Axboe