In order to be sure that 'buff' is never truncated, its size should be 12, not 11. When building with W=1, this fixes the following warnings: drivers/infiniband/hw/mlx4/sysfs.c: In function ‘add_port_entries’: drivers/infiniband/hw/mlx4/sysfs.c:268:34: error: ‘sprintf’ may write a terminating nul past the end of the destination [-Werror=format-overflow=] 268 | sprintf(buff, "%d", i); | ^ drivers/infiniband/hw/mlx4/sysfs.c:268:17: note: ‘sprintf’ output between 2 and 12 bytes into a destination of size 11 268 | sprintf(buff, "%d", i); | ^~~~~~~~~~~~~~~~~~~~~~ drivers/infiniband/hw/mlx4/sysfs.c:286:34: error: ‘sprintf’ may write a terminating nul past the end of the destination [-Werror=format-overflow=] 286 | sprintf(buff, "%d", i); | ^ drivers/infiniband/hw/mlx4/sysfs.c:286:17: note: ‘sprintf’ output between 2 and 12 bytes into a destination of size 11 286 | sprintf(buff, "%d", i); | ^~~~~~~~~~~~~~~~~~~~~~ Fixes: c1e7e466120b ("IB/mlx4: Add iov directory in sysfs under the ib device") Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> --- We could also use snprintf(), but it would just lead to a bigger patch for no additional benefit. This patch is already certainly more a clean-up than a fix. --- drivers/infiniband/hw/mlx4/sysfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/infiniband/hw/mlx4/sysfs.c b/drivers/infiniband/hw/mlx4/sysfs.c index 24ee79aa2122..88f534cf690e 100644 --- a/drivers/infiniband/hw/mlx4/sysfs.c +++ b/drivers/infiniband/hw/mlx4/sysfs.c @@ -223,7 +223,7 @@ void del_sysfs_port_mcg_attr(struct mlx4_ib_dev *device, int port_num, static int add_port_entries(struct mlx4_ib_dev *device, int port_num) { int i; - char buff[11]; + char buff[12]; struct mlx4_ib_iov_port *port = NULL; int ret = 0 ; struct ib_port_attr attr; -- 2.34.1