[PATCH] ice: fix potential infinite loop because loop counter being too small

[PATCH] ice: fix potential infinite loop because loop counter being too small

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

Currently the for-loop counter i is a u8 however it is being checked
against a maximum value hw->num_tx_sched_layers which is a u16. Hence
there is a potential wrap-around of counter i back to zero if
hw->num_tx_sched_layers is greater than 255.  Fix this by making i
a u16.

Addresses-Coverity: ("Infinite loop")
Fixes: b36c598c999c ("ice: Updates to Tx scheduler code")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/net/ethernet/intel/ice/ice_sched.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_sched.c b/drivers/net/ethernet/intel/ice/ice_sched.c
index fc624b73d05d..2fde9653a608 100644
--- a/drivers/net/ethernet/intel/ice/ice_sched.c
+++ b/drivers/net/ethernet/intel/ice/ice_sched.c
@@ -1036,7 +1036,7 @@ enum ice_status ice_sched_query_res_alloc(struct ice_hw *hw)
 	struct ice_aqc_query_txsched_res_resp *buf;
 	enum ice_status status = 0;
 	__le16 max_sibl;
-	u8 i;
+	u16 i;
 
 	if (hw->layer_info)
 		return status;
-- 
2.20.1

RE: [Intel-wired-lan] [PATCH] ice: fix potential infinite loop because loop counter being too small

[Bowers, AndrewX]

> -----Original Message-----
> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On
> Behalf Of Colin King
> Sent: Friday, November 1, 2019 7:00 AM
> To: Kirsher, Jeffrey T <jeffrey.t.kirsher@intel.com>; David S . Miller
> <davem@davemloft.net>; Venkataramanan, Anirudh
> <anirudh.venkataramanan@intel.com>; intel-wired-lan@lists.osuosl.org;
> netdev@vger.kernel.org
> Cc: kernel-janitors@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: [Intel-wired-lan] [PATCH] ice: fix potential infinite loop because loop
> counter being too small
> 
> From: Colin Ian King <colin.king@canonical.com>
> 
> Currently the for-loop counter i is a u8 however it is being checked against a
> maximum value hw->num_tx_sched_layers which is a u16. Hence there is a
> potential wrap-around of counter i back to zero if
> hw->num_tx_sched_layers is greater than 255.  Fix this by making i
> a u16.
> 
> Addresses-Coverity: ("Infinite loop")
> Fixes: b36c598c999c ("ice: Updates to Tx scheduler code")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  drivers/net/ethernet/intel/ice/ice_sched.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)


Tested-by: Andrew Bowers <andrewx.bowers@intel.com>