diff mbox series

[net-next,13/15] net/mlx5e: Check return value of snprintf writing to fw_version buffer for representors

Message ID 20231020030422.67049-14-saeed@kernel.org (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series [net-next,01/15] xfrm: generalize xdo_dev_state_update_curlft to allow statistics update | expand

Checks

Context Check Description
netdev/series_format success Pull request is its own cover letter
netdev/tree_selection success Clearly marked for net-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1363 this patch: 1363
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/build_clang success Errors and warnings before: 1388 this patch: 1388
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1389 this patch: 1388
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 21 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Saeed Mahameed Oct. 20, 2023, 3:04 a.m. UTC 
From: Rahul Rameshbabu <rrameshbabu@nvidia.com>

Treat the operation as an error case when the return value is equivalent to
the size of the name buffer. Failed to write null terminator to the name
buffer, making the string malformed and should not be used. Provide a
string with only the firmware version when forming the string with the
board id fails. This logic for representors is identical to normal flow
with ethtool.

Without check, will trigger -Wformat-truncation with W=1.

    drivers/net/ethernet/mellanox/mlx5/core/en_rep.c: In function 'mlx5e_rep_get_drvinfo':
    drivers/net/ethernet/mellanox/mlx5/core/en_rep.c:78:31: warning: '%.16s' directive output may be truncated writing up to 16 bytes into a region of size between 13 and 22 [-Wformat-truncation=]
      78 |                  "%d.%d.%04d (%.16s)",
         |                               ^~~~~
    drivers/net/ethernet/mellanox/mlx5/core/en_rep.c:77:9: note: 'snprintf' output between 12 and 37 bytes into a destination of size 32
      77 |         snprintf(drvinfo->fw_version, sizeof(drvinfo->fw_version),
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      78 |                  "%d.%d.%04d (%.16s)",
         |                  ~~~~~~~~~~~~~~~~~~~~~
      79 |                  fw_rev_maj(mdev), fw_rev_min(mdev),
         |                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      80 |                  fw_rev_sub(mdev), mdev->board_id);
         |                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6d4ab2e97dcfbcd748ae71761a9d8e5e41cc732c
Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_rep.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c
index 9f0f64ce11c7..e52239df96b8 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c
@@ -71,13 +71,17 @@  static void mlx5e_rep_get_drvinfo(struct net_device *dev,
 {
 	struct mlx5e_priv *priv = netdev_priv(dev);
 	struct mlx5_core_dev *mdev = priv->mdev;
+	int count;
 
 	strscpy(drvinfo->driver, mlx5e_rep_driver_name,
 		sizeof(drvinfo->driver));
-	snprintf(drvinfo->fw_version, sizeof(drvinfo->fw_version),
-		 "%d.%d.%04d (%.16s)",
-		 fw_rev_maj(mdev), fw_rev_min(mdev),
-		 fw_rev_sub(mdev), mdev->board_id);
+	count = snprintf(drvinfo->fw_version, sizeof(drvinfo->fw_version),
+			 "%d.%d.%04d (%.16s)", fw_rev_maj(mdev),
+			 fw_rev_min(mdev), fw_rev_sub(mdev), mdev->board_id);
+	if (count == sizeof(drvinfo->fw_version))
+		snprintf(drvinfo->fw_version, sizeof(drvinfo->fw_version),
+			 "%d.%d.%04d", fw_rev_maj(mdev),
+			 fw_rev_min(mdev), fw_rev_sub(mdev));
 }
 
 static const struct counter_desc sw_rep_stats_desc[] = {