[PATCH][next] ice: Fix potential infinite loop when using u8 loop counter

[PATCH][next] ice: Fix potential infinite loop when using u8 loop counter

[Colin King]

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

A for-loop is using a u8 loop counter that is being compared to
a u32 cmp_dcbcfg->numapp to check for the end of the loop. If
cmp_dcbcfg->numapp is larger than 255 then the counter j will wrap
around to zero and hence an infinite loop occurs. Fix this by making
counter j the same type as cmp_dcbcfg->numapp.

Addresses-Coverity: ("Infinite loop")
Fixes: aeac8ce864d9 ("ice: Recognize 860 as iSCSI port in CEE mode")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/net/ethernet/intel/ice/ice_dcb.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_dcb.c b/drivers/net/ethernet/intel/ice/ice_dcb.c
index 43c6af42de8a..ee4f320d4823 100644
--- a/drivers/net/ethernet/intel/ice/ice_dcb.c
+++ b/drivers/net/ethernet/intel/ice/ice_dcb.c
@@ -747,8 +747,8 @@ ice_cee_to_dcb_cfg(struct ice_aqc_get_cee_dcb_cfg_resp *cee_cfg,
 		   struct ice_port_info *pi)
 {
 	u32 status, tlv_status = le32_to_cpu(cee_cfg->tlv_status);
-	u32 ice_aqc_cee_status_mask, ice_aqc_cee_status_shift;
-	u8 i, j, err, sync, oper, app_index, ice_app_sel_type;
+	u32 ice_aqc_cee_status_mask, ice_aqc_cee_status_shift, j;
+	u8 i, err, sync, oper, app_index, ice_app_sel_type;
 	u16 app_prio = le16_to_cpu(cee_cfg->oper_app_prio);
 	u16 ice_aqc_cee_app_mask, ice_aqc_cee_app_shift;
 	struct ice_dcbx_cfg *cmp_dcbcfg, *dcbcfg;
-- 
2.30.2

RE: [Intel-wired-lan] [PATCH][next] ice: Fix potential infinite loop when using u8 loop counter

[Brelinski, TonyX]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of
> Colin King
> Sent: Wednesday, March 31, 2021 7:46 AM
> To: Brandeburg, Jesse <jesse.brandeburg@intel.com>; Nguyen, Anthony L
> <anthony.l.nguyen@intel.com>; David S . Miller <davem@davemloft.net>;
> Jakub Kicinski <kuba@kernel.org>; Cao, Chinh T <chinh.t.cao@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][next] ice: Fix potential infinite loop when
> using u8 loop counter
> 
> From: Colin Ian King <colin.king@canonical.com>
> 
> A for-loop is using a u8 loop counter that is being compared to a u32
> cmp_dcbcfg->numapp to check for the end of the loop. If cmp_dcbcfg-
> >numapp is larger than 255 then the counter j will wrap around to zero and
> hence an infinite loop occurs. Fix this by making counter j the same type as
> cmp_dcbcfg->numapp.
> 
> Addresses-Coverity: ("Infinite loop")
> Fixes: aeac8ce864d9 ("ice: Recognize 860 as iSCSI port in CEE mode")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  drivers/net/ethernet/intel/ice/ice_dcb.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Tested-by: Tony Brelinski <tonyx.brelinski@intel.com> A Contingent Worker at Intel