[PATCH] net/mlx5: fix build with clang 14

[PATCH] net/mlx5: fix build with clang 14

[David Marchand]

clang 14 raises the following warning:

../drivers/net/mlx5/linux/mlx5_ethdev_os.c:1137:52: error: 'fscanf'
    may overflow; destination buffer in argument 3 has size 16, but the
    corresponding specifier may require size 17
    [-Werror,-Wfortify-source]
                ret = fscanf(file, "%" RTE_STR(IF_NAMESIZE) "s",
                    port_name);

Extend port_name so that it can fit a null terminated string.

Fixes: 63d1db710fbc ("net/mlx5: fix unlimited parsing of switch info")
Fixes: 1256805dd54d ("net/mlx5: move Linux-specific functions")
Cc: stable@dpdk.org

Signed-off-by: David Marchand <david.marchand@redhat.com>
---
 drivers/net/mlx5/linux/mlx5_ethdev_os.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/mlx5/linux/mlx5_ethdev_os.c b/drivers/net/mlx5/linux/mlx5_ethdev_os.c
index 8fe73f1adb..e0a22ac78f 100644
--- a/drivers/net/mlx5/linux/mlx5_ethdev_os.c
+++ b/drivers/net/mlx5/linux/mlx5_ethdev_os.c
@@ -1105,7 +1105,7 @@ int
 mlx5_sysfs_switch_info(unsigned int ifindex, struct mlx5_switch_info *info)
 {
 	char ifname[IF_NAMESIZE];
-	char port_name[IF_NAMESIZE];
+	char port_name[IF_NAMESIZE + 1];
 	FILE *file;
 	struct mlx5_switch_info data = {
 		.master = 0,
-- 
2.36.1

Re: [PATCH] net/mlx5: fix build with clang 14

[Bruce Richardson]

On Wed, May 18, 2022 at 11:11:00AM +0200, David Marchand wrote:
> clang 14 raises the following warning:
> 
> ../drivers/net/mlx5/linux/mlx5_ethdev_os.c:1137:52: error: 'fscanf'
>     may overflow; destination buffer in argument 3 has size 16, but the
>     corresponding specifier may require size 17
>     [-Werror,-Wfortify-source]
>                 ret = fscanf(file, "%" RTE_STR(IF_NAMESIZE) "s",
>                     port_name);
> 
> Extend port_name so that it can fit a null terminated string.
> 
> Fixes: 63d1db710fbc ("net/mlx5: fix unlimited parsing of switch info")
> Fixes: 1256805dd54d ("net/mlx5: move Linux-specific functions")
> Cc: stable@dpdk.org
> 
> Signed-off-by: David Marchand <david.marchand@redhat.com>
> ---
>  drivers/net/mlx5/linux/mlx5_ethdev_os.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
Seeing this error with Ubuntu 22.04, and this patch fixes the issue.

Tested-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>

Re: [PATCH] net/mlx5: fix build with clang 14

[David Marchand]

On Wed, May 11, 2022 at 3:59 PM Ali Alnubani <alialnu@nvidia.com> wrote:
>
> Use fgets instead of fscanf to resolve the following warning
> reported by clang 14.0.0 in Fedora 37 (Rawhide):
>
> drivers/net/mlx5/linux/mlx5_ethdev_os.c:1137:52: error:
>   'fscanf' may overflow; destination buffer in argument 3 has size 16,
>   but the corresponding specifier may require size 17
>   [-Werror,-Wfortify-source]
>   ret = fscanf(file, "%" RTE_STR(IF_NAMESIZE) "s", port_name);
>
> Fixes: 63d1db710fbc ("net/mlx5: fix unlimited parsing of switch info")
> Cc: michaelba@mellanox.com
> Cc: stable@dpdk.org
>
> Signed-off-by: Ali Alnubani <alialnu@nvidia.com>
> ---
>  drivers/net/mlx5/linux/mlx5_ethdev_os.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/mlx5/linux/mlx5_ethdev_os.c b/drivers/net/mlx5/linux/mlx5_ethdev_os.c
> index 8fe73f1adb..3d28597e7b 100644
> --- a/drivers/net/mlx5/linux/mlx5_ethdev_os.c
> +++ b/drivers/net/mlx5/linux/mlx5_ethdev_os.c
> @@ -1118,7 +1118,7 @@ mlx5_sysfs_switch_info(unsigned int ifindex, struct mlx5_switch_info *info)
>         bool port_switch_id_set = false;
>         bool device_dir = false;
>         char c;
> -       int ret;
> +       char *ret;
>
>         if (!if_indextoname(ifindex, ifname)) {
>                 rte_errno = errno;
> @@ -1134,9 +1134,9 @@ mlx5_sysfs_switch_info(unsigned int ifindex, struct mlx5_switch_info *info)
>
>         file = fopen(phys_port_name, "rb");
>         if (file != NULL) {
> -               ret = fscanf(file, "%" RTE_STR(IF_NAMESIZE) "s", port_name);
> +               ret = fgets(port_name, IF_NAMESIZE, file);
>                 fclose(file);
> -               if (ret == 1)
> +               if (ret != NULL)
>                         mlx5_translate_port_name(port_name, &data);

You can directly check fgets return value and remove (misleading)
variable ret from the global scope of this function.


>         }
>         file = fopen(phys_switch_id, "rb");



-- 
David Marchand

[PATCH] net/mlx5: fix build with clang 14

[Ali Alnubani]

Use fgets instead of fscanf to resolve the following warning
reported by clang 14.0.0 in Fedora 37 (Rawhide):

drivers/net/mlx5/linux/mlx5_ethdev_os.c:1137:52: error:
  'fscanf' may overflow; destination buffer in argument 3 has size 16,
  but the corresponding specifier may require size 17
  [-Werror,-Wfortify-source]
  ret = fscanf(file, "%" RTE_STR(IF_NAMESIZE) "s", port_name);

Fixes: 63d1db710fbc ("net/mlx5: fix unlimited parsing of switch info")
Cc: michaelba@mellanox.com
Cc: stable@dpdk.org

Signed-off-by: Ali Alnubani <alialnu@nvidia.com>
---
 drivers/net/mlx5/linux/mlx5_ethdev_os.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/mlx5/linux/mlx5_ethdev_os.c b/drivers/net/mlx5/linux/mlx5_ethdev_os.c
index 8fe73f1adb..3d28597e7b 100644
--- a/drivers/net/mlx5/linux/mlx5_ethdev_os.c
+++ b/drivers/net/mlx5/linux/mlx5_ethdev_os.c
@@ -1118,7 +1118,7 @@ mlx5_sysfs_switch_info(unsigned int ifindex, struct mlx5_switch_info *info)
 	bool port_switch_id_set = false;
 	bool device_dir = false;
 	char c;
-	int ret;
+	char *ret;
 
 	if (!if_indextoname(ifindex, ifname)) {
 		rte_errno = errno;
@@ -1134,9 +1134,9 @@ mlx5_sysfs_switch_info(unsigned int ifindex, struct mlx5_switch_info *info)
 
 	file = fopen(phys_port_name, "rb");
 	if (file != NULL) {
-		ret = fscanf(file, "%" RTE_STR(IF_NAMESIZE) "s", port_name);
+		ret = fgets(port_name, IF_NAMESIZE, file);
 		fclose(file);
-		if (ret == 1)
+		if (ret != NULL)
 			mlx5_translate_port_name(port_name, &data);
 	}
 	file = fopen(phys_switch_id, "rb");
-- 
2.25.1