[PATCH] spi: bcm-qspi: Fix use after free in bcm_qspi_probe() in error path

From: Florian Fainelli
Date: Wed Oct 11 2017 - 17:59:40 EST


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@xxxxxxxxx>
---
drivers/spi/spi-bcm-qspi.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c
index 6ef6c44f39f5..a172ab299e80 100644
--- a/drivers/spi/spi-bcm-qspi.c
+++ b/drivers/spi/spi-bcm-qspi.c
@@ -1250,7 +1250,7 @@ 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");
@@ -1272,7 +1272,7 @@ 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;
}
}

@@ -1280,7 +1280,7 @@ 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++) {
@@ -1369,8 +1369,9 @@ int bcm_qspi_probe(struct platform_device *pdev,
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 */
--
2.9.3