[dpdk-dev] [PATCH] net/tap: fix crash from unitialized memory in rte_flow_destroy

[Stephen Hemminger]

The TAP driver does not initialize all the elements of the rte_flow
structure. This can lead to crash in rte_flow_destroy.

(gdb) where
    flow=0x100e99280, error=0x0)
    at drivers/net/tap/tap_flow.c:1514

(gdb) p remote_flow
$1 = (struct rte_flow *) 0x6b6b6b6b6b6b6b6b

Which is here:
static int
tap_flow_destroy_pmd(struct pmd_internals *pmd,
		     struct rte_flow *flow,
		     struct rte_flow_error *error)
{
	struct rte_flow *remote_flow = flow->remote_flow;
...
	if (remote_flow) {
		remote_flow->msg.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;

Simplest fix is to use rte_zmalloc() so remote_flow and other fields
are always set at zero.

Fixes: 2bc06869cd94 ("net/tap: add remote netdevice traffic capture")
Cc: pascal.mazon at 6wind.com
Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
---
 drivers/net/tap/tap_flow.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/tap/tap_flow.c b/drivers/net/tap/tap_flow.c
index 9d90361d9924..1538349e9c92 100644
--- a/drivers/net/tap/tap_flow.c
+++ b/drivers/net/tap/tap_flow.c
@@ -1380,7 +1380,7 @@ tap_flow_create(struct rte_eth_dev *dev,
 			NULL, "priority value too big");
 		goto fail;
 	}
-	flow = rte_malloc(__func__, sizeof(struct rte_flow), 0);
+	flow = rte_zmalloc(__func__, sizeof(struct rte_flow), 0);
 	if (!flow) {
 		rte_flow_error_set(error, ENOMEM, RTE_FLOW_ERROR_TYPE_HANDLE,
 				   NULL, "cannot allocate memory for rte_flow");
@@ -1416,7 +1416,7 @@ tap_flow_create(struct rte_eth_dev *dev,
 	 * to the local pmd->if_index.
 	 */
 	if (pmd->remote_if_index) {
-		remote_flow = rte_malloc(__func__, sizeof(struct rte_flow), 0);
+		remote_flow = rte_zmalloc(__func__, sizeof(struct rte_flow), 0);
 		if (!remote_flow) {
 			rte_flow_error_set(
 				error, ENOMEM, RTE_FLOW_ERROR_TYPE_HANDLE, NULL,
@@ -1693,7 +1693,7 @@ int tap_flow_implicit_create(struct pmd_internals *pmd,
 		}
 	};
 
-	remote_flow = rte_malloc(__func__, sizeof(struct rte_flow), 0);
+	remote_flow = rte_zmalloc(__func__, sizeof(struct rte_flow), 0);
 	if (!remote_flow) {
 		TAP_LOG(ERR, "Cannot allocate memory for rte_flow");
 		goto fail;
@@ -1896,7 +1896,7 @@ static int rss_enable(struct pmd_internals *pmd,
 			return -ENOTSUP;
 		}
 
-		rss_flow = rte_malloc(__func__, sizeof(struct rte_flow), 0);
+		rss_flow = rte_zmalloc(__func__, sizeof(struct rte_flow), 0);
 		if (!rss_flow) {
 			TAP_LOG(ERR,
 				"Cannot allocate memory for rte_flow");
-- 
2.20.1