Michael S. Tsirkin
2023-Jul-23 09:22 UTC
[PATCH v1] vdpa: Complement vdpa_nl_policy for nlattr length check
On Sun, Jul 23, 2023 at 04:05:07PM +0800, Lin Ma wrote:> The vdpa_nl_policy structure is used to validate the nlattr when parsing > the incoming nlmsg. It will ensure the attribute being described produces > a valid nlattr pointer in info->attrs before entering into each handler > in vdpa_nl_ops. > > That is to say, the missing part in vdpa_nl_policy may lead to illegal > nlattr after parsing, which could lead to OOB read just like CVE-2023-3773.Hmm. https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-3773 ** RESERVED ** This candidate has been reserved by an organization or individual that will use it when announcing a new security problem. When the candidate has been publicized, the details for this candidate will be provided.> This patch adds three missing nla_policy to avoid such bugs. > > Fixes: 90fea5a800c3 ("vdpa: device feature provisioning") > Fixes: 13b00b135665 ("vdpa: Add support for querying vendor statistics") > Fixes: ad69dd0bf26b ("vdpa: Introduce query of device config layout") > Signed-off-by: Lin Ma <linma at zju.edu.cn>I don't know how OOB triggers but this duplication is problematic I think: we are likely to forget again in the future. Isn't there a way to block everything that is not listed?> --- > drivers/vdpa/vdpa.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c > index 965e32529eb8..f2f654fd84e5 100644 > --- a/drivers/vdpa/vdpa.c > +++ b/drivers/vdpa/vdpa.c > @@ -1247,8 +1247,11 @@ static const struct nla_policy vdpa_nl_policy[VDPA_ATTR_MAX + 1] = { > [VDPA_ATTR_MGMTDEV_DEV_NAME] = { .type = NLA_STRING }, > [VDPA_ATTR_DEV_NAME] = { .type = NLA_STRING }, > [VDPA_ATTR_DEV_NET_CFG_MACADDR] = NLA_POLICY_ETH_ADDR, > + [VDPA_ATTR_DEV_NET_CFG_MAX_VQP] = { .type = NLA_U16 }, > /* virtio spec 1.1 section 5.1.4.1 for valid MTU range */ > [VDPA_ATTR_DEV_NET_CFG_MTU] = NLA_POLICY_MIN(NLA_U16, 68), > + [VDPA_ATTR_DEV_QUEUE_INDEX] = { .type = NLA_U32 }, > + [VDPA_ATTR_DEV_FEATURES] = { .type = NLA_U64 }, > }; > > static const struct genl_ops vdpa_nl_ops[] = { > -- > 2.17.1