| Message ID | 20250116181700.96437-1-colin.i.king@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [next] net/mlx5: fix unintentional sign extension on shift of dest_attr->vport.vhca_id | expand |
On Thu, Jan 16, 2025 at 06:17:00PM +0000, Colin Ian King wrote: > Shifting dest_attr->vport.vhca_id << 16 results in a promotion from an > unsigned 16 bit integer to a 32 bit signed integer, this is then sign > extended to a 64 bit unsigned long on 64 bitarchitectures. If vhca_id is > greater than 0x7fff then this leads to a sign extended result where all > the upper 32 bits of idx are set to 1. Fix this by casting vhca_id > to the same type as idx before performing the shift. > > Fixes: 8e2e08a6d1e0 ("net/mlx5: fs, add support for dest vport HWS action") > Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org>
On 1/16/2025 8:17 PM, Colin Ian King wrote: > Shifting dest_attr->vport.vhca_id << 16 results in a promotion from an > unsigned 16 bit integer to a 32 bit signed integer, this is then sign > extended to a 64 bit unsigned long on 64 bitarchitectures. If vhca_id is > greater than 0x7fff then this leads to a sign extended result where all > the upper 32 bits of idx are set to 1. Fix this by casting vhca_id > to the same type as idx before performing the shift. > > Fixes: 8e2e08a6d1e0 ("net/mlx5: fs, add support for dest vport HWS action") > Signed-off-by: Colin Ian King<colin.i.king@gmail.com> Acked-by: Moshe Shemesh <moshe@nvidia.com>
Hello: This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Thu, 16 Jan 2025 18:17:00 +0000 you wrote: > Shifting dest_attr->vport.vhca_id << 16 results in a promotion from an > unsigned 16 bit integer to a 32 bit signed integer, this is then sign > extended to a 64 bit unsigned long on 64 bitarchitectures. If vhca_id is > greater than 0x7fff then this leads to a sign extended result where all > the upper 32 bits of idx are set to 1. Fix this by casting vhca_id > to the same type as idx before performing the shift. > > [...] Here is the summary with links: - [next] net/mlx5: fix unintentional sign extension on shift of dest_attr->vport.vhca_id https://git.kernel.org/netdev/net-next/c/41c5d104f338 You are awesome, thank you!
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/fs_hws.c b/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/fs_hws.c index 05329afeb9ea..f34bbbbba1c2 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/fs_hws.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/fs_hws.c @@ -417,7 +417,7 @@ mlx5_fs_get_dest_action_vport(struct mlx5_fs_hws_context *fs_ctx, vport_num = is_dest_type_uplink ? MLX5_VPORT_UPLINK : dest_attr->vport.num; if (vhca_id_valid) { dests_xa = &fs_ctx->hws_pool.vport_vhca_dests; - idx = dest_attr->vport.vhca_id << 16 | vport_num; + idx = (unsigned long)dest_attr->vport.vhca_id << 16 | vport_num; } else { dests_xa = &fs_ctx->hws_pool.vport_dests; idx = vport_num;
Shifting dest_attr->vport.vhca_id << 16 results in a promotion from an unsigned 16 bit integer to a 32 bit signed integer, this is then sign extended to a 64 bit unsigned long on 64 bitarchitectures. If vhca_id is greater than 0x7fff then this leads to a sign extended result where all the upper 32 bits of idx are set to 1. Fix this by casting vhca_id to the same type as idx before performing the shift. Fixes: 8e2e08a6d1e0 ("net/mlx5: fs, add support for dest vport HWS action") Signed-off-by: Colin Ian King <colin.i.king@gmail.com> --- drivers/net/ethernet/mellanox/mlx5/core/steering/hws/fs_hws.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)