ch4/ofi: multi-nic setup bugfix

This patch fixes an out-of-bound bug when more than MPIDI_OFI_MAX_NICS
nics are discovered, causing illegal access to
MPIDI_OFI_global_t.prov_use array.

Signed-off-by: Wenduo Wang <wenduwan@amazon.com>

src/mpid/ch4/netmod/ofi/ofi_nic.c

@@ -86,12 +86,6 @@ int MPIDI_OFI_init_multi_nic(struct fi_info *prov)
 {
     int mpi_errno = MPI_SUCCESS;
     int nic_count = 0;
-    int max_nics = MPIR_CVAR_CH4_OFI_MAX_NICS;
-
-    if (MPIR_CVAR_CH4_OFI_MAX_NICS == 0 || MPIR_CVAR_CH4_OFI_MAX_NICS <= -2) {
-        /* Invalid values for the CVAR will default to single nic */
-        max_nics = 1;
-    }
 
     /* Count the number of NICs */
     struct fi_info *first_prov = NULL;
@@ -113,10 +107,7 @@ int MPIDI_OFI_init_multi_nic(struct fi_info *prov)
             !MPIDI_OFI_nic_already_used(p, MPIDI_OFI_global.prov_use, nic_count)) {
             MPIDI_OFI_global.prov_use[nic_count] = fi_dupinfo(p);
             MPIR_Assert(MPIDI_OFI_global.prov_use[nic_count]);
-            nic_count++;
-            if (nic_count == max_nics) {
-                break;
-            }
+            ++nic_count;
         }
 #endif
     }
@@ -181,12 +172,18 @@ static int setup_multi_nic(int nic_count)
     MPIDI_OFI_nic_info_t *nics = MPIDI_OFI_global.nic_info;
     MPIR_CHKLMEM_DECL(1);
 
-    MPIDI_OFI_global.num_nics = nic_count;
-
     /* Initially sort the NICs by name. This way all intranode ranks have a consistent view. */
     qsort(MPIDI_OFI_global.prov_use, MPIDI_OFI_global.num_nics, sizeof(struct fi_info *),
           compare_nic_names);
 
+    if (nic_count > MPIDI_OFI_MAX_NICS) {
+        fprintf(stderr, "Warning: Detected %d NICs, but only %d(MPIDI_OFI_MAX_NICS) are considered.\n",
+                nic_count, MPIDI_OFI_MAX_NICS);
+        nic_count = MPIDI_OFI_MAX_NICS;
+    }
+
+    MPIDI_OFI_global.num_nics = nic_count;
+
     /* Limit the number of physical NICs depending on the CVAR */
     if (MPIR_CVAR_CH4_OFI_MAX_NICS > 0 && MPIDI_OFI_global.num_nics > MPIR_CVAR_CH4_OFI_MAX_NICS) {
         for (int i = MPIR_CVAR_CH4_OFI_MAX_NICS; i < MPIDI_OFI_global.num_nics; ++i) {