[PATCH 3.16 311/366] vmxnet3: avoid assumption about invalid dma_pa in vmxnet3_set_mc()

Ben Hutchings
2018-10-14T23:11:48Z

From: Alexey Khoroshilov <khoroshilov@ispras.ru>

commit fb5c6cfaec126d9a96b9dd471d4711bf4c737a6f upstream.

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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/net/vmxnet3/vmxnet3_drv.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)

--- a/drivers/net/vmxnet3/vmxnet3_drv.c
+++ b/drivers/net/vmxnet3/vmxnet3_drv.c
@@ -2078,6 +2078,7 @@ 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) {
@@ -2105,13 +2106,15 @@ vmxnet3_set_mc(struct net_device *netdev
new_table,
rxConf->mfTableLen,
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;
@@ -2136,7 +2139,7 @@ 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);