On Tue, Oct 3, 2023 at 4:17 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote: > > Prepare for the coming implementation by GCC and Clang of the __counted_by > attribute. Flexible array members annotated with __counted_by can have > their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for > array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family > functions). > > As found with Coccinelle[1], add __counted_by for struct mlx5_fc_bulk. > > Cc: Saeed Mahameed <saeedm@xxxxxxxxxx> > Cc: Leon Romanovsky <leon@xxxxxxxxxx> > Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> > Cc: Eric Dumazet <edumazet@xxxxxxxxxx> > Cc: Jakub Kicinski <kuba@xxxxxxxxxx> > Cc: Paolo Abeni <pabeni@xxxxxxxxxx> > Cc: netdev@xxxxxxxxxxxxxxx > Cc: linux-rdma@xxxxxxxxxxxxxxx > Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1] > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> > --- > drivers/net/ethernet/mellanox/mlx5/core/fs_counters.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fs_counters.c b/drivers/net/ethernet/mellanox/mlx5/core/fs_counters.c > index 17fe30a4c06c..0c26d707eed2 100644 > --- a/drivers/net/ethernet/mellanox/mlx5/core/fs_counters.c > +++ b/drivers/net/ethernet/mellanox/mlx5/core/fs_counters.c > @@ -539,7 +539,7 @@ struct mlx5_fc_bulk { > u32 base_id; > int bulk_len; > unsigned long *bitmask; > - struct mlx5_fc fcs[]; > + struct mlx5_fc fcs[] __counted_by(bulk_len); > }; This looks good. `bulk->bulk_len` is assigned before flexible array member `fcs` is accessed. bulk->bulk_len = bulk_len; for (i = 0; i < bulk_len; i++) { mlx5_fc_init(&bulk->fcs[i], bulk, base_id + i); set_bit(i, bulk->bitmask); } Reviewed-by: Justin Stitt <justinstitt@xxxxxxxxxx> > > static void mlx5_fc_init(struct mlx5_fc *counter, struct mlx5_fc_bulk *bulk, > -- > 2.34.1 > > Thanks Justin
