net/mlx5e: Correct snprintf truncation handling for fw_version buffer

snprintf returns the length of the formatted string, excluding the trailing
null, without accounting for truncation. This means that is the return
value is greater than or equal to the size parameter, the fw_version string
was truncated.

Reported-by: David Laight <David.Laight@ACULAB.COM>
Closes: https://lore.kernel.org/netdev/81cae734ee1b4cde9b380a9a31006c1a@AcuMS.aculab.com/
Link: https://docs.kernel.org/core-api/kernel-api.html#c.snprintf
Fixes: 41e63c2baa ("net/mlx5e: Check return value of snprintf writing to fw_version buffer")
Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
This commit is contained in:
Rahul Rameshbabu 2023-11-21 15:00:21 -08:00 committed by Saeed Mahameed
parent d792e5f7f1
commit ad436b9c12

View File

@ -49,7 +49,7 @@ void mlx5e_ethtool_get_drvinfo(struct mlx5e_priv *priv,
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))
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));