LU-9909 lnet: fix memory leak and lnet_interfaces_max

Free buffer allocated for discover command.

Set lnet_interfaces_max to LNET_INTERFACES_MAX_DEFAULT if
it's not defined or if it's being set to something below
LNET_INTERFACES_MIN.

For lnet_ping() and lnet_discover() if the provided space
can fit more NIDs than lnet_interfaces_max then ensure only
lnet_interfaces_max is copied into the buffer.

Test-Parameters: trivial
Signed-off-by: Amir Shehata <amir.shehata@intel.com>
Change-Id: I19aed712f40a8bf44d2fb112588e9ae07257469f
Reviewed-on: https://review.whamcloud.com/28702
Tested-by: Jenkins
Reviewed-by: Sonia Sharma <sonia.sharma@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Olaf Weber <olaf.weber@hpe.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>

diff --git a/lnet/lnet/api-ni.c b/lnet/lnet/api-ni.c
index a9b1839..db67866 100644 (file)
--- a/lnet/lnet/api-ni.c
+++ b/lnet/lnet/api-ni.c
@@ -167,8 +167,8 @@ intf_max_set(const char *val, struct kernel_param *kp)
 
        if (value < LNET_INTERFACES_MIN) {
                CWARN("max interfaces provided are too small, setting to %d\n",
-                     LNET_INTERFACES_MIN);
-               value = LNET_INTERFACES_MIN;
+                     LNET_INTERFACES_MAX_DEFAULT);
+               value = LNET_INTERFACES_MAX_DEFAULT;
        }
 
        *(int *)kp->arg = value;
@@ -3465,9 +3465,16 @@ static int lnet_ping(struct lnet_process_id id, signed long timeout,
        sigset_t blocked;
 
        /* n_ids limit is arbitrary */
-       if (n_ids <= 0 || n_ids > lnet_interfaces_max || id.nid == LNET_NID_ANY)
+       if (n_ids <= 0 || id.nid == LNET_NID_ANY)
                return -EINVAL;
 
+       /*
+        * if the user buffer has more space than the lnet_interfaces_max
+        * then only fill it up to lnet_interfaces_max
+        */
+       if (n_ids > lnet_interfaces_max)
+               n_ids = lnet_interfaces_max;
+
        if (id.pid == LNET_PID_ANY)
                id.pid = LNET_PID_LUSTRE;
 
@@ -3636,16 +3643,25 @@ lnet_discover(lnet_process_id_t id, __u32 force, lnet_process_id_t __user *ids,
        int i;
        int rc;
        int max_intf = lnet_interfaces_max;
+       size_t buf_size;
 
        if (n_ids <= 0 ||
-           id.nid == LNET_NID_ANY ||
-           n_ids > max_intf)
+           id.nid == LNET_NID_ANY)
                return -EINVAL;
 
        if (id.pid == LNET_PID_ANY)
                id.pid = LNET_PID_LUSTRE;
 
-       LIBCFS_ALLOC(buf, n_ids * sizeof(*buf));
+       /*
+        * if the user buffer has more space than the max_intf
+        * then only fill it up to max_intf
+        */
+       if (n_ids > max_intf)
+               n_ids = max_intf;
+
+       buf_size = n_ids * sizeof(*buf);
+
+       LIBCFS_ALLOC(buf, buf_size);
        if (!buf)
                return -ENOMEM;
 
@@ -3698,5 +3714,7 @@ out_decref:
 out:
        lnet_net_unlock(cpt);
 
+       LIBCFS_FREE(buf, buf_size);
+
        return rc;
 }