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

From: Colin Ian King <redacted>

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 <redacted>
---
 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

-----Original Message-----
From: Intel-wired-lan <redacted> On Behalf Of
Colin King
Sent: Wednesday, March 31, 2021 7:46 AM
To: Brandeburg, Jesse <redacted>; Nguyen, Anthony L
[off-list ref]; David S . Miller [off-list ref];
Jakub Kicinski [off-list ref]; Cao, Chinh T [off-list ref];
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 <redacted>

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-

quoted

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 <redacted>
---
 drivers/net/ethernet/intel/ice/ice_dcb.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Tested-by: Tony Brelinski <redacted> A Contingent Worker at Intel