vmxnet3: avoid assumption about invalid dma_pa in vmxnet3_set_mc()

vmxnet3_set_mc() checks new_table_pa returned by dma_map_single()
with dma_mapping_error(), but even there it assumes zero is invalid pa
(it assumes dma_mapping_error(...,0) returns true if new_table is NULL).

The patch adds an explicit variable to track status of new_table_pa.

Found by Linux Driver Verification project (linuxtesting.org).

v2: use "bool" and "true"/"false" for boolean variables.
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 7 deletions

diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c
index b5554f2ebee4..ef83ae3b0a44 100644
--- a/drivers/net/vmxnet3/vmxnet3_drv.c
+++ b/drivers/net/vmxnet3/vmxnet3_drv.c
@@ -2279,6 +2279,7 @@ vmxnet3_set_mc(struct net_device *netdev)
                                         &adapter->shared->devRead.rxFilterConf;
         u8 *new_table = NULL;
         dma_addr_t new_table_pa = 0;
+        bool new_table_pa_valid = false;
         u32 new_mode = VMXNET3_RXM_UCAST;
 
         if (netdev->flags & IFF_PROMISC) {
@@ -2307,13 +2308,15 @@ vmxnet3_set_mc(struct net_device *netdev)
                                                         new_table,
                                                         sz,
                                                         PCI_DMA_TODEVICE);
+                                if (!dma_mapping_error(&adapter->pdev->dev,
+                                                       new_table_pa)) {
+                                        new_mode |= VMXNET3_RXM_MCAST;
+                                        new_table_pa_valid = true;
+                                        rxConf->mfTablePA = cpu_to_le64(
+                                                                new_table_pa);
+                                }
                         }
-
-                        if (!dma_mapping_error(&adapter->pdev->dev,
-                                               new_table_pa)) {
-                                new_mode |= VMXNET3_RXM_MCAST;
-                                rxConf->mfTablePA = cpu_to_le64(new_table_pa);
-                        } else {
+                        if (!new_table_pa_valid) {
                                 netdev_info(netdev,
                                             "failed to copy mcast list, setting ALL_MULTI\n");
                                 new_mode |= VMXNET3_RXM_ALL_MULTI;
@@ -2338,7 +2341,7 @@ vmxnet3_set_mc(struct net_device *netdev)
                                VMXNET3_CMD_UPDATE_MAC_FILTERS);
         spin_unlock_irqrestore(&adapter->cmd_lock, flags);
 
-        if (new_table_pa)
+        if (new_table_pa_valid)
                 dma_unmap_single(&adapter->pdev->dev, new_table_pa,
                                  rxConf->mfTableLen, PCI_DMA_TODEVICE);
         kfree(new_table);