[PATCH 5.4 084/320] media: msi001: fix possible null-ptr-deref in msi001_probe()

Greg Kroah-Hartman
2022-01-24T19:32:14Z

From: Wang Hai <wanghai38@huawei.com>

[ Upstream commit 3d5831a40d3464eea158180eb12cbd81c5edfb6a ]

I got a null-ptr-deref report:

BUG: kernel NULL pointer dereference, address: 0000000000000060
...
RIP: 0010:v4l2_ctrl_auto_cluster+0x57/0x270
...
Call Trace:
msi001_probe+0x13b/0x24b [msi001]
spi_probe+0xeb/0x130
...
do_syscall_64+0x35/0xb0

In msi001_probe(), if the creation of control for bandwidth_auto
fails, there will be a null-ptr-deref issue when it is used in
v4l2_ctrl_auto_cluster().

Check dev->hdl.error before v4l2_ctrl_auto_cluster() to fix this bug.

Link: https://lore.kernel.org/linux-media/20211026112348.2878040-1-wanghai38@huawei.com
Fixes: 93203dd6c7c4 ("[media] msi001: Mirics MSi001 silicon tuner driver")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/tuners/msi001.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/media/tuners/msi001.c b/drivers/media/tuners/msi001.c
index 78e6fd600d8ef..44247049a3190 100644
--- a/drivers/media/tuners/msi001.c
+++ b/drivers/media/tuners/msi001.c
@@ -442,6 +442,13 @@ static int msi001_probe(struct spi_device *spi)
V4L2_CID_RF_TUNER_BANDWIDTH_AUTO, 0, 1, 1, 1);
dev->bandwidth = v4l2_ctrl_new_std(&dev->hdl, &msi001_ctrl_ops,
V4L2_CID_RF_TUNER_BANDWIDTH, 200000, 8000000, 1, 200000);
+ if (dev->hdl.error) {
+ ret = dev->hdl.error;
+ dev_err(&spi->dev, "Could not initialize controls\n");
+ /* control init failed, free handler */
+ goto err_ctrl_handler_free;
+ }
+
v4l2_ctrl_auto_cluster(2, &dev->bandwidth_auto, 0, false);
dev->lna_gain = v4l2_ctrl_new_std(&dev->hdl, &msi001_ctrl_ops,
V4L2_CID_RF_TUNER_LNA_GAIN, 0, 1, 1, 1);
--
2.34.1