common/mlx5: fix netlink buffer allocation from stack

The buffer size to receive netlink reply messages is relatively
large (32K), and it is allocated on the stack and it might
break in application is using smaller per-thread stacks.
This patch allocates temporary buffer from heap.

Fixes: ccdcba53a3f4 ("net/mlx5: use Netlink to add/remove MAC addresses")
Cc: stable@dpdk.org
Reported-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>

diff --git a/drivers/common/mlx5/mlx5_nl.c b/drivers/common/mlx5/mlx5_nl.c
index 65efcd3..1a1033a 100644 (file)
--- a/drivers/common/mlx5/mlx5_nl.c
+++ b/drivers/common/mlx5/mlx5_nl.c
@@ -330,10 +330,10 @@ mlx5_nl_recv(int nlsk_fd, uint32_t sn, int (*cb)(struct nlmsghdr *, void *arg),
             void *arg)
 {
        struct sockaddr_nl sa;
-       char buf[MLX5_RECV_BUF_SIZE];
+       void *buf = malloc(MLX5_RECV_BUF_SIZE);
        struct iovec iov = {
                .iov_base = buf,
-               .iov_len = sizeof(buf),
+               .iov_len = MLX5_RECV_BUF_SIZE,
        };
        struct msghdr msg = {
                .msg_name = &sa,
@@ -345,6 +345,10 @@ mlx5_nl_recv(int nlsk_fd, uint32_t sn, int (*cb)(struct nlmsghdr *, void *arg),
        int multipart = 0;
        int ret = 0;
 
+       if (!buf) {
+               rte_errno = ENOMEM;
+               return -rte_errno;
+       }
        do {
                struct nlmsghdr *nh;
                int recv_bytes = 0;
@@ -353,7 +357,8 @@ mlx5_nl_recv(int nlsk_fd, uint32_t sn, int (*cb)(struct nlmsghdr *, void *arg),
                        recv_bytes = recvmsg(nlsk_fd, &msg, 0);
                        if (recv_bytes == -1) {
                                rte_errno = errno;
-                               return -rte_errno;
+                               ret = -rte_errno;
+                               goto exit;
                        }
                        nh = (struct nlmsghdr *)buf;
                } while (nh->nlmsg_seq != sn);
@@ -365,24 +370,30 @@ mlx5_nl_recv(int nlsk_fd, uint32_t sn, int (*cb)(struct nlmsghdr *, void *arg),
 
                                if (err_data->error < 0) {
                                        rte_errno = -err_data->error;
-                                       return -rte_errno;
+                                       ret = -rte_errno;
+                                       goto exit;
                                }
                                /* Ack message. */
-                               return 0;
+                               ret = 0;
+                               goto exit;
                        }
                        /* Multi-part msgs and their trailing DONE message. */
                        if (nh->nlmsg_flags & NLM_F_MULTI) {
-                               if (nh->nlmsg_type == NLMSG_DONE)
-                                       return 0;
+                               if (nh->nlmsg_type == NLMSG_DONE) {
+                                       ret =  0;
+                                       goto exit;
+                               }
                                multipart = 1;
                        }
                        if (cb) {
                                ret = cb(nh, arg);
                                if (ret < 0)
-                                       return ret;
+                                       goto exit;
                        }
                }
        } while (multipart);
+exit:
+       free(buf);
        return ret;
 }