RDMA/netlink: Audit policy settings for netlink attributes

For all string attributes for which we don't currently accept the element
as input, we only use it as output, set the string length to
RDMA_NLDEV_ATTR_EMPTY_STRING which is defined as 1.  That way we will only
accept a null string for that element.  This will prevent someone from
writing a new input routine that uses the element without also updating
the policy to have a valid value.

Also while there, make sure the existing entries that are valid have the
correct policy, if not, correct the policy.  Remove unnecessary checks
for nla_strlcpy() overflow once the policy has been set correctly.

Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c
index 6006d23d04100a2dcba50f547a1033a49e313908..5499f5629dc26b1f0a28cafa156444ec290cdd4e 100644 (file)
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c
@@ -49,29 +49,29 @@ static const struct nla_policy nldev_policy[RDMA_NLDEV_ATTR_MAX] = {
        [RDMA_NLDEV_ATTR_CHARDEV]               = { .type = NLA_U64 },
        [RDMA_NLDEV_ATTR_CHARDEV_ABI]           = { .type = NLA_U64 },
        [RDMA_NLDEV_ATTR_CHARDEV_NAME]          = { .type = NLA_NUL_STRING,
-                                       .len = RDMA_NLDEV_ATTR_ENTRY_STRLEN },
+                                       .len = RDMA_NLDEV_ATTR_EMPTY_STRING },
        [RDMA_NLDEV_ATTR_CHARDEV_TYPE]          = { .type = NLA_NUL_STRING,
-                                       .len = 128 },
+                                       .len = RDMA_NLDEV_ATTR_CHARDEV_TYPE_SIZE },
        [RDMA_NLDEV_ATTR_DEV_INDEX]             = { .type = NLA_U32 },
        [RDMA_NLDEV_ATTR_DEV_NAME]              = { .type = NLA_NUL_STRING,
-                                       .len = IB_DEVICE_NAME_MAX - 1},
+                                       .len = IB_DEVICE_NAME_MAX },
        [RDMA_NLDEV_ATTR_DEV_NODE_TYPE]         = { .type = NLA_U8 },
        [RDMA_NLDEV_ATTR_DEV_PROTOCOL]          = { .type = NLA_NUL_STRING,
-                                       .len = RDMA_NLDEV_ATTR_ENTRY_STRLEN },
+                                       .len = RDMA_NLDEV_ATTR_EMPTY_STRING },
        [RDMA_NLDEV_ATTR_DRIVER]                = { .type = NLA_NESTED },
        [RDMA_NLDEV_ATTR_DRIVER_ENTRY]          = { .type = NLA_NESTED },
        [RDMA_NLDEV_ATTR_DRIVER_PRINT_TYPE]     = { .type = NLA_U8 },
        [RDMA_NLDEV_ATTR_DRIVER_STRING]         = { .type = NLA_NUL_STRING,
-                                       .len = RDMA_NLDEV_ATTR_ENTRY_STRLEN },
+                                       .len = RDMA_NLDEV_ATTR_EMPTY_STRING },
        [RDMA_NLDEV_ATTR_DRIVER_S32]            = { .type = NLA_S32 },
        [RDMA_NLDEV_ATTR_DRIVER_S64]            = { .type = NLA_S64 },
        [RDMA_NLDEV_ATTR_DRIVER_U32]            = { .type = NLA_U32 },
        [RDMA_NLDEV_ATTR_DRIVER_U64]            = { .type = NLA_U64 },
        [RDMA_NLDEV_ATTR_FW_VERSION]            = { .type = NLA_NUL_STRING,
-                                       .len = IB_FW_VERSION_NAME_MAX - 1},
+                                       .len = RDMA_NLDEV_ATTR_EMPTY_STRING },
        [RDMA_NLDEV_ATTR_LID]                   = { .type = NLA_U32 },
        [RDMA_NLDEV_ATTR_LINK_TYPE]             = { .type = NLA_NUL_STRING,
-                                       .len = RDMA_NLDEV_ATTR_ENTRY_STRLEN },
+                                       .len = IFNAMSIZ },
        [RDMA_NLDEV_ATTR_LMC]                   = { .type = NLA_U8 },
        [RDMA_NLDEV_ATTR_NDEV_INDEX]            = { .type = NLA_U32 },
        [RDMA_NLDEV_ATTR_NDEV_NAME]             = { .type = NLA_NUL_STRING,
@@ -92,7 +92,7 @@ static const struct nla_policy nldev_policy[RDMA_NLDEV_ATTR_MAX] = {
                        .len = sizeof(struct __kernel_sockaddr_storage) },
        [RDMA_NLDEV_ATTR_RES_IOVA]              = { .type = NLA_U64 },
        [RDMA_NLDEV_ATTR_RES_KERN_NAME]         = { .type = NLA_NUL_STRING,
-                                       .len = TASK_COMM_LEN },
+                                       .len = RDMA_NLDEV_ATTR_EMPTY_STRING },
        [RDMA_NLDEV_ATTR_RES_LKEY]              = { .type = NLA_U32 },
        [RDMA_NLDEV_ATTR_RES_LOCAL_DMA_LKEY]    = { .type = NLA_U32 },
        [RDMA_NLDEV_ATTR_RES_LQPN]              = { .type = NLA_U32 },
@@ -120,7 +120,7 @@ static const struct nla_policy nldev_policy[RDMA_NLDEV_ATTR_MAX] = {
        [RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY]     = { .type = NLA_NESTED },
        [RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_CURR]= { .type = NLA_U64 },
        [RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_NAME]= { .type = NLA_NUL_STRING,
-                                       .len = 16 },
+                                       .len = RDMA_NLDEV_ATTR_EMPTY_STRING },
        [RDMA_NLDEV_ATTR_RES_TYPE]              = { .type = NLA_U8 },
        [RDMA_NLDEV_ATTR_RES_UNSAFE_GLOBAL_RKEY]= { .type = NLA_U32 },
        [RDMA_NLDEV_ATTR_RES_USECNT]            = { .type = NLA_U64 },
@@ -1361,7 +1361,7 @@ static int nldev_get_chardev(struct sk_buff *skb, struct nlmsghdr *nlh,
                             struct netlink_ext_ack *extack)
 {
        struct nlattr *tb[RDMA_NLDEV_ATTR_MAX];
-       char client_name[IB_DEVICE_NAME_MAX];
+       char client_name[RDMA_NLDEV_ATTR_CHARDEV_TYPE_SIZE];
        struct ib_client_nl_info data = {};
        struct ib_device *ibdev = NULL;
        struct sk_buff *msg;
@@ -1373,9 +1373,8 @@ static int nldev_get_chardev(struct sk_buff *skb, struct nlmsghdr *nlh,
        if (err || !tb[RDMA_NLDEV_ATTR_CHARDEV_TYPE])
                return -EINVAL;
 
-       if (nla_strlcpy(client_name, tb[RDMA_NLDEV_ATTR_CHARDEV_TYPE],
-                       sizeof(client_name)) >= sizeof(client_name))
-               return -EINVAL;
+       nla_strlcpy(client_name, tb[RDMA_NLDEV_ATTR_CHARDEV_TYPE],
+                   sizeof(client_name));
 
        if (tb[RDMA_NLDEV_ATTR_DEV_INDEX]) {
                index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);

diff --git a/include/rdma/rdma_netlink.h b/include/rdma/rdma_netlink.h
index c7acbe08342828194a57502dca2568c4bbd66804..6631624e4d7c542dd196387d82be263a7e61be4f 100644 (file)
--- a/include/rdma/rdma_netlink.h
+++ b/include/rdma/rdma_netlink.h
@@ -6,6 +6,12 @@
 #include <linux/netlink.h>
 #include <uapi/rdma/rdma_netlink.h>
 
+enum {
+       RDMA_NLDEV_ATTR_EMPTY_STRING = 1,
+       RDMA_NLDEV_ATTR_ENTRY_STRLEN = 16,
+       RDMA_NLDEV_ATTR_CHARDEV_TYPE_SIZE = 32,
+};
+
 struct rdma_nl_cbs {
        int (*doit)(struct sk_buff *skb, struct nlmsghdr *nlh,
                    struct netlink_ext_ack *extack);

diff --git a/include/uapi/rdma/rdma_netlink.h b/include/uapi/rdma/rdma_netlink.h
index b27c02185dcc19ea2eb481473831475eb37555f7..650cee8c4bf183aaa5653530116355e6dd5961e5 100644 (file)
--- a/include/uapi/rdma/rdma_netlink.h
+++ b/include/uapi/rdma/rdma_netlink.h
@@ -284,10 +284,6 @@ enum rdma_nldev_command {
        RDMA_NLDEV_NUM_OPS
 };
 
-enum {
-       RDMA_NLDEV_ATTR_ENTRY_STRLEN = 16,
-};
-
 enum rdma_nldev_print_type {
        RDMA_NLDEV_PRINT_TYPE_UNSPEC,
        RDMA_NLDEV_PRINT_TYPE_HEX,