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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Colin Ian King <colin.king@canonical.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Sasha Levin <alexander.levin@microsoft.com>
Subject: [PATCH 4.16 066/279] scsi: isci: Fix infinite loop in while loop
Date:   Mon, 18 Jun 2018 10:10:51 +0200
Message-Id: <20180618080611.559487016@linuxfoundation.org>
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4.16-stable review patch.  If anyone has any objections, please let me know.

------------------

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

[ Upstream commit 4bc83b3f272fe8f36450f9c003df49cf07ffe5fd ]

In the case when the phy_mask is bitwise anded with the phy_index bit is
zero the continue statement currently jumps to the next iteration of the
while loop and phy_index is never actually incremented, potentially
causing an infinite loop if phy_index is less than SCI_MAX_PHS. Fix this
by turning the while loop into a for loop.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/scsi/isci/port_config.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/scsi/isci/port_config.c
+++ b/drivers/scsi/isci/port_config.c
@@ -291,7 +291,7 @@ sci_mpc_agent_validate_phy_configuration
 		 * Note: We have not moved the current phy_index so we will actually
 		 *       compare the startting phy with itself.
 		 *       This is expected and required to add the phy to the port. */
-		while (phy_index < SCI_MAX_PHYS) {
+		for (; phy_index < SCI_MAX_PHYS; phy_index++) {
 			if ((phy_mask & (1 << phy_index)) == 0)
 				continue;
 			sci_phy_get_sas_address(&ihost->phys[phy_index],
@@ -311,7 +311,6 @@ sci_mpc_agent_validate_phy_configuration
 					      &ihost->phys[phy_index]);
 
 			assigned_phy_mask |= (1 << phy_index);
-			phy_index++;
 		}
 
 	}