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

[Andrew Rybchenko]

Adding list and maintainers back.

On 7/13/21 1:18 PM, Yu, DapengX wrote:
>> -----Original Message-----
>> From: Andrew Rybchenko <andrew.rybchenko at oktetlabs.ru>
>> Sent: Tuesday, July 13, 2021 6:11 PM
>> To: Yu, DapengX <dapengx.yu at intel.com>; Singh, Jasvinder
>> <jasvinder.singh at intel.com>; Dumitrescu, Cristian
>> <cristian.dumitrescu at intel.com>
>> Cc: dev at dpdk.org; stable at 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 at intel.com wrote:
>>> From: Dapeng Yu <dapengx.yu at intel.com>
>>>
>>> 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 at dpdk.org
>>>
>>> Signed-off-by: Dapeng Yu <dapengx.yu at intel.com>
>>> ---
>>> 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.

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