[PATCH] examples/ethtool: fix buffer size for pkt pool name

[PATCH] examples/ethtool: fix buffer size for pkt pool name

[Shani Peretz]

Increase str_name buffer size from 16 to 32 bytes to fit the provided
format. The previous size was insufficient as the format
string "pkt_pool%i" can produce up to 19 bytes (8 for "pkt_pool",
up to 10 for integer value, and 1 for null terminator).

Fixes: bda68ab9d1e7 ("examples/ethtool: add user-space ethtool sample application")
Cc: stable@dpdk.org

Signed-off-by: Shani Peretz <shperetz@nvidia.com>
---
 examples/ethtool/ethtool-app/main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/examples/ethtool/ethtool-app/main.c b/examples/ethtool/ethtool-app/main.c
index 1f011a9321..06605b4202 100644
--- a/examples/ethtool/ethtool-app/main.c
+++ b/examples/ethtool/ethtool-app/main.c
@@ -92,7 +92,7 @@ static void setup_ports(struct app_config *app_cfg, int cnt_ports)
 	int size_pktpool;
 	struct rte_eth_conf cfg_port;
 	struct rte_eth_dev_info dev_info;
-	char str_name[16];
+	char str_name[32];
 	uint16_t nb_rxd = PORT_RX_QUEUE_SIZE;
 	uint16_t nb_txd = PORT_TX_QUEUE_SIZE;
 	int ret;
@@ -112,7 +112,7 @@ static void setup_ports(struct app_config *app_cfg, int cnt_ports)
 		size_pktpool = dev_info.rx_desc_lim.nb_max +
 			dev_info.tx_desc_lim.nb_max + PKTPOOL_EXTRA_SIZE;
 
-		snprintf(str_name, 16, "pkt_pool%i", idx_port);
+		snprintf(str_name, sizeof(str_name), "pkt_pool%i", idx_port);
 		ptr_port->pkt_pool = rte_pktmbuf_pool_create(
 			str_name,
 			size_pktpool, PKTPOOL_CACHE,
-- 
2.34.1

Re: [PATCH] examples/ethtool: fix buffer size for pkt pool name

[Stephen Hemminger]

On Wed, 3 Dec 2025 13:01:57 +0200
Shani Peretz <shperetz@nvidia.com> wrote:

> Increase str_name buffer size from 16 to 32 bytes to fit the provided
> format. The previous size was insufficient as the format
> string "pkt_pool%i" can produce up to 19 bytes (8 for "pkt_pool",
> up to 10 for integer value, and 1 for null terminator).
> 
> Fixes: bda68ab9d1e7 ("examples/ethtool: add user-space ethtool sample application")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Shani Peretz <shperetz@nvidia.com>
> ---
>  examples/ethtool/ethtool-app/main.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/examples/ethtool/ethtool-app/main.c b/examples/ethtool/ethtool-app/main.c
> index 1f011a9321..06605b4202 100644
> --- a/examples/ethtool/ethtool-app/main.c
> +++ b/examples/ethtool/ethtool-app/main.c
> @@ -92,7 +92,7 @@ static void setup_ports(struct app_config *app_cfg, int cnt_ports)
>  	int size_pktpool;
>  	struct rte_eth_conf cfg_port;
>  	struct rte_eth_dev_info dev_info;
> -	char str_name[16];
> +	char str_name[32];

Don't use hard coded constant, instead use RTE_MEMPOOL_NAMESIZE which is
not 32, but 32 - 4 + 1 = 29