From: Vlad Buslov vladbu@nvidia.com
commit 350d9a823734b5a7e767cddc3bdde5f0bcbb7ff4 upstream.
Even though net_device->name is guaranteed to be null-terminated string of size<=IFNAMSIZ, the test robot complains that return value of netdev_name() can be larger:
In file included from include/trace/define_trace.h:102, from drivers/net/ethernet/mellanox/mlx5/core/esw/diag/bridge_tracepoint.h:113, from drivers/net/ethernet/mellanox/mlx5/core/esw/bridge.c:12: drivers/net/ethernet/mellanox/mlx5/core/esw/diag/bridge_tracepoint.h: In function 'trace_event_raw_event_mlx5_esw_bridge_fdb_template':
drivers/net/ethernet/mellanox/mlx5/core/esw/diag/bridge_tracepoint.h:24:29: warning: 'strncpy' output may be truncated copying 16 bytes from a string of length 20 [-Wstringop-truncation]
24 | strncpy(__entry->dev_name, | ^~~~~~~~~~~~~~~~~~~~~~~~~~ 25 | netdev_name(fdb->dev), | ~~~~~~~~~~~~~~~~~~~~~~ 26 | IFNAMSIZ); | ~~~~~~~~~
This is caused by the fact that default value of IFNAMSIZ is 16, while placeholder value that is returned by netdev_name() for unnamed net devices is larger than that.
The offending code is in a tracing function that is only called for mlx5 representors, so there is no straightforward way to reproduce the issue but let's fix it for correctness sake by replacing strncpy() with strscpy() to ensure that resulting string is always null-terminated.
Fixes: 9724fd5d9c2a ("net/mlx5: Bridge, add tracepoints") Reported-by: kernel test robot lkp@intel.com Signed-off-by: Vlad Buslov vladbu@nvidia.com Reviewed-by: Roi Dayan roid@nvidia.com Signed-off-by: Saeed Mahameed saeedm@nvidia.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/mellanox/mlx5/core/esw/diag/bridge_tracepoint.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/net/ethernet/mellanox/mlx5/core/esw/diag/bridge_tracepoint.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/esw/diag/bridge_tracepoint.h @@ -21,7 +21,7 @@ DECLARE_EVENT_CLASS(mlx5_esw_bridge_fdb_ __field(unsigned int, used) ), TP_fast_assign( - strncpy(__entry->dev_name, + strscpy(__entry->dev_name, netdev_name(fdb->dev), IFNAMSIZ); memcpy(__entry->addr, fdb->key.addr, ETH_ALEN);