ipc: harden message receive

Currently, IPC does not check received messages for invalid data
and passes them to user code unchanged. This may result in buffer
overruns on reading message data. Fix this by checking the message
length and fd number on receive, and discard any messages that
are not valid.

Fixes: bacaa2754017 ("eal: add channel for multi-process communication")
Cc: stable@dpdk.org
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>

diff --git a/lib/librte_eal/common/eal_common_proc.c b/lib/librte_eal/common/eal_common_proc.c
index 8586474..6ffd476 100644 (file)
--- a/lib/librte_eal/common/eal_common_proc.c
+++ b/lib/librte_eal/common/eal_common_proc.c
@@ -285,7 +285,15 @@ read_msg(struct mp_msg_internal *m, struct sockaddr_un *s)
                        break;
                }
        }
-
+       /* sanity-check the response */
+       if (m->msg.num_fds < 0 || m->msg.num_fds > RTE_MP_MAX_FD_NUM) {
+               RTE_LOG(ERR, EAL, "invalid number of fd's received\n");
+               return -1;
+       }
+       if (m->msg.len_param < 0 || m->msg.len_param > RTE_MP_MAX_PARAM_LEN) {
+               RTE_LOG(ERR, EAL, "invalid received data length\n");
+               return -1;
+       }
        return 0;
 }