[PATCH AUTOSEL 4.9 23/60] media: gspca: zero usb_buf on error

From: Sasha Levin
Date: Sun Sep 22 2019 - 15:07:30 EST


From: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>

[ Upstream commit 4843a543fad3bf8221cf14e5d5f32d15cee89e84 ]

If reg_r() fails, then gspca_dev->usb_buf was left uninitialized,
and some drivers used the contents of that buffer in logic.

This caused several syzbot errors:

https://syzkaller.appspot.com/bug?extid=397fd082ce5143e2f67d
https://syzkaller.appspot.com/bug?extid=1a35278dd0ebfb3a038a
https://syzkaller.appspot.com/bug?extid=06ddf1788cfd048c5e82

I analyzed the gspca drivers and zeroed the buffer where needed.

Reported-and-tested-by: syzbot+1a35278dd0ebfb3a038a@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-and-tested-by: syzbot+397fd082ce5143e2f67d@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-and-tested-by: syzbot+06ddf1788cfd048c5e82@xxxxxxxxxxxxxxxxxxxxxxxxx

Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/media/usb/gspca/konica.c | 5 +++++
drivers/media/usb/gspca/nw80x.c | 5 +++++
drivers/media/usb/gspca/ov519.c | 10 ++++++++++
drivers/media/usb/gspca/ov534.c | 5 +++++
drivers/media/usb/gspca/ov534_9.c | 1 +
drivers/media/usb/gspca/se401.c | 5 +++++
drivers/media/usb/gspca/sn9c20x.c | 5 +++++
drivers/media/usb/gspca/sonixb.c | 5 +++++
drivers/media/usb/gspca/sonixj.c | 5 +++++
drivers/media/usb/gspca/spca1528.c | 5 +++++
drivers/media/usb/gspca/sq930x.c | 5 +++++
drivers/media/usb/gspca/sunplus.c | 5 +++++
drivers/media/usb/gspca/vc032x.c | 5 +++++
drivers/media/usb/gspca/w996Xcf.c | 5 +++++
14 files changed, 71 insertions(+)

diff --git a/drivers/media/usb/gspca/konica.c b/drivers/media/usb/gspca/konica.c
index 78542fff403fc..5a37d32e8fd09 100644
--- a/drivers/media/usb/gspca/konica.c
+++ b/drivers/media/usb/gspca/konica.c
@@ -127,6 +127,11 @@ static void reg_r(struct gspca_dev *gspca_dev, u16 value, u16 index)
if (ret < 0) {
pr_err("reg_r err %d\n", ret);
gspca_dev->usb_err = ret;
+ /*
+ * Make sure the buffer is zeroed to avoid uninitialized
+ * values.
+ */
+ memset(gspca_dev->usb_buf, 0, 2);
}
}

diff --git a/drivers/media/usb/gspca/nw80x.c b/drivers/media/usb/gspca/nw80x.c
index 599f755e75b86..7ebeee98dc1bb 100644
--- a/drivers/media/usb/gspca/nw80x.c
+++ b/drivers/media/usb/gspca/nw80x.c
@@ -1584,6 +1584,11 @@ static void reg_r(struct gspca_dev *gspca_dev,
if (ret < 0) {
pr_err("reg_r err %d\n", ret);
gspca_dev->usb_err = ret;
+ /*
+ * Make sure the buffer is zeroed to avoid uninitialized
+ * values.
+ */
+ memset(gspca_dev->usb_buf, 0, USB_BUF_SZ);
return;
}
if (len == 1)
diff --git a/drivers/media/usb/gspca/ov519.c b/drivers/media/usb/gspca/ov519.c
index 965372a5ff2f3..7ac38905080ad 100644
--- a/drivers/media/usb/gspca/ov519.c
+++ b/drivers/media/usb/gspca/ov519.c
@@ -2087,6 +2087,11 @@ static int reg_r(struct sd *sd, u16 index)
} else {
PERR("reg_r %02x failed %d\n", index, ret);
sd->gspca_dev.usb_err = ret;
+ /*
+ * Make sure the result is zeroed to avoid uninitialized
+ * values.
+ */
+ gspca_dev->usb_buf[0] = 0;
}

return ret;
@@ -2115,6 +2120,11 @@ static int reg_r8(struct sd *sd,
} else {
PERR("reg_r8 %02x failed %d\n", index, ret);
sd->gspca_dev.usb_err = ret;
+ /*
+ * Make sure the buffer is zeroed to avoid uninitialized
+ * values.
+ */
+ memset(gspca_dev->usb_buf, 0, 8);
}

return ret;
diff --git a/drivers/media/usb/gspca/ov534.c b/drivers/media/usb/gspca/ov534.c
index 9266a5c9abc5d..ba289b4530772 100644
--- a/drivers/media/usb/gspca/ov534.c
+++ b/drivers/media/usb/gspca/ov534.c
@@ -645,6 +645,11 @@ static u8 ov534_reg_read(struct gspca_dev *gspca_dev, u16 reg)
if (ret < 0) {
pr_err("read failed %d\n", ret);
gspca_dev->usb_err = ret;
+ /*
+ * Make sure the result is zeroed to avoid uninitialized
+ * values.
+ */
+ gspca_dev->usb_buf[0] = 0;
}
return gspca_dev->usb_buf[0];
}
diff --git a/drivers/media/usb/gspca/ov534_9.c b/drivers/media/usb/gspca/ov534_9.c
index 47085cf2d7236..f2dca06069355 100644
--- a/drivers/media/usb/gspca/ov534_9.c
+++ b/drivers/media/usb/gspca/ov534_9.c
@@ -1157,6 +1157,7 @@ static u8 reg_r(struct gspca_dev *gspca_dev, u16 reg)
if (ret < 0) {
pr_err("reg_r err %d\n", ret);
gspca_dev->usb_err = ret;
+ return 0;
}
return gspca_dev->usb_buf[0];
}
diff --git a/drivers/media/usb/gspca/se401.c b/drivers/media/usb/gspca/se401.c
index 5102cea504710..6adbb0eca71fe 100644
--- a/drivers/media/usb/gspca/se401.c
+++ b/drivers/media/usb/gspca/se401.c
@@ -115,6 +115,11 @@ static void se401_read_req(struct gspca_dev *gspca_dev, u16 req, int silent)
pr_err("read req failed req %#04x error %d\n",
req, err);
gspca_dev->usb_err = err;
+ /*
+ * Make sure the buffer is zeroed to avoid uninitialized
+ * values.
+ */
+ memset(gspca_dev->usb_buf, 0, READ_REQ_SIZE);
}
}

diff --git a/drivers/media/usb/gspca/sn9c20x.c b/drivers/media/usb/gspca/sn9c20x.c
index 10269dad9d201..1a08a7a20114c 100644
--- a/drivers/media/usb/gspca/sn9c20x.c
+++ b/drivers/media/usb/gspca/sn9c20x.c
@@ -923,6 +923,11 @@ static void reg_r(struct gspca_dev *gspca_dev, u16 reg, u16 length)
if (unlikely(result < 0 || result != length)) {
pr_err("Read register %02x failed %d\n", reg, result);
gspca_dev->usb_err = result;
+ /*
+ * Make sure the buffer is zeroed to avoid uninitialized
+ * values.
+ */
+ memset(gspca_dev->usb_buf, 0, USB_BUF_SZ);
}
}

diff --git a/drivers/media/usb/gspca/sonixb.c b/drivers/media/usb/gspca/sonixb.c
index 6696b2ec34e96..83e98b85ab6a1 100644
--- a/drivers/media/usb/gspca/sonixb.c
+++ b/drivers/media/usb/gspca/sonixb.c
@@ -466,6 +466,11 @@ static void reg_r(struct gspca_dev *gspca_dev,
dev_err(gspca_dev->v4l2_dev.dev,
"Error reading register %02x: %d\n", value, res);
gspca_dev->usb_err = res;
+ /*
+ * Make sure the result is zeroed to avoid uninitialized
+ * values.
+ */
+ gspca_dev->usb_buf[0] = 0;
}
}

diff --git a/drivers/media/usb/gspca/sonixj.c b/drivers/media/usb/gspca/sonixj.c
index d49d76ec14212..9ec63f75b8ea4 100644
--- a/drivers/media/usb/gspca/sonixj.c
+++ b/drivers/media/usb/gspca/sonixj.c
@@ -1174,6 +1174,11 @@ static void reg_r(struct gspca_dev *gspca_dev,
if (ret < 0) {
pr_err("reg_r err %d\n", ret);
gspca_dev->usb_err = ret;
+ /*
+ * Make sure the buffer is zeroed to avoid uninitialized
+ * values.
+ */
+ memset(gspca_dev->usb_buf, 0, USB_BUF_SZ);
}
}

diff --git a/drivers/media/usb/gspca/spca1528.c b/drivers/media/usb/gspca/spca1528.c
index f38fd8949609f..ee93bd443df5d 100644
--- a/drivers/media/usb/gspca/spca1528.c
+++ b/drivers/media/usb/gspca/spca1528.c
@@ -84,6 +84,11 @@ static void reg_r(struct gspca_dev *gspca_dev,
if (ret < 0) {
pr_err("reg_r err %d\n", ret);
gspca_dev->usb_err = ret;
+ /*
+ * Make sure the buffer is zeroed to avoid uninitialized
+ * values.
+ */
+ memset(gspca_dev->usb_buf, 0, USB_BUF_SZ);
}
}

diff --git a/drivers/media/usb/gspca/sq930x.c b/drivers/media/usb/gspca/sq930x.c
index e274cf19a3ea2..b236e9dcd4685 100644
--- a/drivers/media/usb/gspca/sq930x.c
+++ b/drivers/media/usb/gspca/sq930x.c
@@ -438,6 +438,11 @@ static void reg_r(struct gspca_dev *gspca_dev,
if (ret < 0) {
pr_err("reg_r %04x failed %d\n", value, ret);
gspca_dev->usb_err = ret;
+ /*
+ * Make sure the buffer is zeroed to avoid uninitialized
+ * values.
+ */
+ memset(gspca_dev->usb_buf, 0, USB_BUF_SZ);
}
}

diff --git a/drivers/media/usb/gspca/sunplus.c b/drivers/media/usb/gspca/sunplus.c
index 46c9f2229a186..cc3e1478c5a09 100644
--- a/drivers/media/usb/gspca/sunplus.c
+++ b/drivers/media/usb/gspca/sunplus.c
@@ -268,6 +268,11 @@ static void reg_r(struct gspca_dev *gspca_dev,
if (ret < 0) {
pr_err("reg_r err %d\n", ret);
gspca_dev->usb_err = ret;
+ /*
+ * Make sure the buffer is zeroed to avoid uninitialized
+ * values.
+ */
+ memset(gspca_dev->usb_buf, 0, USB_BUF_SZ);
}
}

diff --git a/drivers/media/usb/gspca/vc032x.c b/drivers/media/usb/gspca/vc032x.c
index b4efb2fb36fa3..5032b9d7d9bb2 100644
--- a/drivers/media/usb/gspca/vc032x.c
+++ b/drivers/media/usb/gspca/vc032x.c
@@ -2919,6 +2919,11 @@ static void reg_r_i(struct gspca_dev *gspca_dev,
if (ret < 0) {
pr_err("reg_r err %d\n", ret);
gspca_dev->usb_err = ret;
+ /*
+ * Make sure the buffer is zeroed to avoid uninitialized
+ * values.
+ */
+ memset(gspca_dev->usb_buf, 0, USB_BUF_SZ);
}
}
static void reg_r(struct gspca_dev *gspca_dev,
diff --git a/drivers/media/usb/gspca/w996Xcf.c b/drivers/media/usb/gspca/w996Xcf.c
index 896f1b2b91793..948aaae4d47eb 100644
--- a/drivers/media/usb/gspca/w996Xcf.c
+++ b/drivers/media/usb/gspca/w996Xcf.c
@@ -147,6 +147,11 @@ static int w9968cf_read_sb(struct sd *sd)
} else {
pr_err("Read SB reg [01] failed\n");
sd->gspca_dev.usb_err = ret;
+ /*
+ * Make sure the buffer is zeroed to avoid uninitialized
+ * values.
+ */
+ memset(sd->gspca_dev.usb_buf, 0, 2);
}

udelay(W9968CF_I2C_BUS_DELAY);
--
2.20.1