Re: [dpdk-dev] [PATCH v2] net/softnic: fix memory leak in parsing arguments

Adding list and maintainers back.

On 7/13/21 1:18 PM, Yu, DapengX wrote:

quoted

-----Original Message-----
From: Andrew Rybchenko <redacted>
Sent: Tuesday, July 13, 2021 6:11 PM
To: Yu, DapengX <redacted>; Singh, Jasvinder
[off-list ref]; Dumitrescu, Cristian
[off-list ref]
Cc: dev@dpdk.org; stable@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v2] net/softnic: fix memory leak in parsing
arguments

On 7/13/21 1:08 PM, dapengx.yu@intel.com wrote:

quoted

From: Dapeng Yu <redacted>

In function pmd_parse_args(), firmware path is duplicated from device
arguments as character string, but is never freed, which cause memory
leak.

This patch changes the type of firmware member of struct pmd_params to
character array, to make memory resource release unnecessary, and
changes the type of name member to character array, to keep the
consistency of character string handling in struct pmd_params.

Fixes: 7e68bc20f8c8 ("net/softnic: restructure")
Cc: stable@dpdk.org

Signed-off-by: Dapeng Yu <redacted>
---
V2:
* improve the patch according to maintainer's comment:
  rte_strscpy() is the best option here.
---
 drivers/net/softnic/rte_eth_softnic.c           | 9 ++++++---
 drivers/net/softnic/rte_eth_softnic_internals.h | 4 ++--
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/net/softnic/rte_eth_softnic.c

b/drivers/net/softnic/rte_eth_softnic.c
index f64023256d..8a49e83dce 100644

--- a/drivers/net/softnic/rte_eth_softnic.c
+++ b/drivers/net/softnic/rte_eth_softnic.c

@@ -440,6 +440,7 @@ pmd_parse_args(struct pmd_params *p, const char

*params)  {
 	struct rte_kvargs *kvlist;
 	int ret = 0;
+	char *firmware = NULL;

 	kvlist = rte_kvargs_parse(params, pmd_valid_args);
 	if (kvlist == NULL)

@@ -447,7 +448,7 @@ pmd_parse_args(struct pmd_params *p, const char

*params)

 	/* Set default values */
 	memset(p, 0, sizeof(*p));
-	p->firmware = SOFTNIC_FIRMWARE;
+	rte_strscpy(p->firmware, SOFTNIC_FIRMWARE, sizeof(p-
firmware));

I still don't understand why return value is not checked here and in similar
cases below.

If the return value is not checked here, and the dst path string is not complete when the path string is too long, softnic_cli_script_process() will prompt error.
So the fix will not cause more negative impact.
And for the similar case below, the src and dst string length is same always,  so no negative impact too.

I see. For me it sounds a bit fragile, but not critical.
Anyway since I'm not 100% sure I'll wait for maintainers
review.

quoted

quoted

 	p->cpu_id = SOFTNIC_CPU_ID;
 	p->sc = SOFTNIC_SC;
 	p->tm.n_queues = SOFTNIC_TM_N_QUEUES; @@ -468,10 +469,12

@@

quoted

pmd_parse_args(struct pmd_params *p, const char *params)
 	/* Firmware script (optional) */
 	if (rte_kvargs_count(kvlist, PMD_PARAM_FIRMWARE) == 1) {
 		ret = rte_kvargs_process(kvlist, PMD_PARAM_FIRMWARE,
-			&get_string, &p->firmware);
+			&get_string, &firmware);
 		if (ret < 0)
 			goto out_free;
 	}
+	rte_strscpy(p->firmware, firmware, sizeof(p->firmware));
+	free(firmware);

 	/* Connection listening port (optional) */
 	if (rte_kvargs_count(kvlist, PMD_PARAM_CONN_PORT) == 1) { @@

-621,7

quoted

+624,7 @@ pmd_probe(struct rte_vdev_device *vdev)
 	if (status)
 		return status;

-	p.name = name;
+	rte_strscpy(p.name, name, sizeof(p.name));

 	/* Allocate and initialize soft ethdev private data */
 	dev_private = pmd_init(&p);

diff --git a/drivers/net/softnic/rte_eth_softnic_internals.h

b/drivers/net/softnic/rte_eth_softnic_internals.h
index 1b3186ef0b..a13d67b7c1 100644

--- a/drivers/net/softnic/rte_eth_softnic_internals.h
+++ b/drivers/net/softnic/rte_eth_softnic_internals.h

@@ -34,8 +34,8 @@
  */

 struct pmd_params {
-	const char *name;
-	const char *firmware;
+	char name[RTE_DEV_NAME_MAX_LEN];
+	char firmware[PATH_MAX];
 	uint16_t conn_port;
 	uint32_t cpu_id;
 	int sc; /**< Service cores. */