From d8e5f2f8d507ac717eebef87a3df95ed5c6927b6 Mon Sep 17 00:00:00 2001
From: Florian Fainelli <f.fainelli@gmail.com>
Date: Wed, 11 Oct 2017 14:59:22 -0700
Subject: spi: bcm-qspi: Fix use after free in bcm_qspi_probe() in error path

commit c0368e4db4a3e8a3dce40f3f621c06e14c560d79 upstream.

There was an inversion in how the error path in bcm_qspi_probe() is done
which would make us trip over a KASAN use-after-free report. Turns out
that qspi->dev_ids does not get allocated until later in the probe
process. Fix this by introducing a new lable: qspi_resource_err which
takes care of cleaning up the SPI master instance.

Fixes: fa236a7ef240 ("spi: bcm-qspi: Add Broadcom MSPI driver")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c
index 14f9dea..7d629b4 100644
--- a/drivers/spi/spi-bcm-qspi.c
+++ b/drivers/spi/spi-bcm-qspi.c
@@ -1215,7 +1215,7 @@ int bcm_qspi_probe(struct platform_device *pdev,
 			goto qspi_probe_err;
 		}
 	} else {
-		goto qspi_probe_err;
+		goto qspi_resource_err;
 	}
 
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "bspi");
@@ -1237,7 +1237,7 @@ int bcm_qspi_probe(struct platform_device *pdev,
 		qspi->base[CHIP_SELECT]  = devm_ioremap_resource(dev, res);
 		if (IS_ERR(qspi->base[CHIP_SELECT])) {
 			ret = PTR_ERR(qspi->base[CHIP_SELECT]);
-			goto qspi_probe_err;
+			goto qspi_resource_err;
 		}
 	}
 
@@ -1245,7 +1245,7 @@ int bcm_qspi_probe(struct platform_device *pdev,
 				GFP_KERNEL);
 	if (!qspi->dev_ids) {
 		ret = -ENOMEM;
-		goto qspi_probe_err;
+		goto qspi_resource_err;
 	}
 
 	for (val = 0; val < num_irqs; val++) {
@@ -1334,8 +1334,9 @@ qspi_reg_err:
 	bcm_qspi_hw_uninit(qspi);
 	clk_disable_unprepare(qspi->clk);
 qspi_probe_err:
-	spi_master_put(master);
 	kfree(qspi->dev_ids);
+qspi_resource_err:
+	spi_master_put(master);
 	return ret;
 }
 /* probe function to be called by SoC specific platform driver probe */
-- 
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