From 98ddd5bfec2b32a99d92494f015765b8efb0394c Mon Sep 17 00:00:00 2001 From: Rahul Rameshbabu Date: Tue, 14 Nov 2023 13:58:46 -0800 Subject: [PATCH] net/mlx5e: Check return value of snprintf writing to fw_version buffer for representors [ Upstream commit 1b2bd0c0264febcd8d47209079a6671c38e6558b ] 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); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Fixes: cf83c8fdcd47 ("net/mlx5e: Add missing ethtool driver info for representors") Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6d4ab2e97dcfbcd748ae71761a9d8e5e41cc732c Signed-off-by: Rahul Rameshbabu Reviewed-by: Dragos Tatulea Signed-off-by: Saeed Mahameed Link: https://lore.kernel.org/r/20231114215846.5902-16-saeed@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/mellanox/mlx5/core/en_rep.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c index fd1cce5..825f9c6 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[] = { -- 2.7.4