media: gspca: zero usb_buf on error

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@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+397fd082ce5143e2f67d@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+06ddf1788cfd048c5e82@syzkaller.appspotmail.com
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

diff --git a/drivers/media/usb/gspca/konica.c b/drivers/media/usb/gspca/konica.c
index d8e4013..53db9a2 100644 (file)
--- a/drivers/media/usb/gspca/konica.c
+++ b/drivers/media/usb/gspca/konica.c
@@ -114,6 +114,11 @@ 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 5964970..880f569 100644 (file)
--- a/drivers/media/usb/gspca/nw80x.c
+++ b/drivers/media/usb/gspca/nw80x.c
@@ -1572,6 +1572,11 @@ 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 cfb1f53..f417dfc 100644 (file)
--- a/drivers/media/usb/gspca/ov519.c
+++ b/drivers/media/usb/gspca/ov519.c
@@ -2073,6 +2073,11 @@ static int reg_r(struct sd *sd, u16 index)
        } else {
                gspca_err(gspca_dev, "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;
@@ -2101,6 +2106,11 @@ static int reg_r8(struct sd *sd,
        } else {
                gspca_err(gspca_dev, "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 56521c9..185c1f1 100644 (file)
--- a/drivers/media/usb/gspca/ov534.c
+++ b/drivers/media/usb/gspca/ov534.c
@@ -693,6 +693,11 @@ 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 867f860..91efc65 100644 (file)
--- a/drivers/media/usb/gspca/ov534_9.c
+++ b/drivers/media/usb/gspca/ov534_9.c
@@ -1145,6 +1145,7 @@ 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 061deee..e087cfb 100644 (file)
--- a/drivers/media/usb/gspca/se401.c
+++ b/drivers/media/usb/gspca/se401.c
@@ -101,6 +101,11 @@ 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 b43f89f..12a2395 100644 (file)
--- a/drivers/media/usb/gspca/sn9c20x.c
+++ b/drivers/media/usb/gspca/sn9c20x.c
@@ -909,6 +909,11 @@ 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 046fc2c..4d655e2 100644 (file)
--- a/drivers/media/usb/gspca/sonixb.c
+++ b/drivers/media/usb/gspca/sonixb.c
@@ -453,6 +453,11 @@ 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 50a6c84..2e1bd2d 100644 (file)
--- a/drivers/media/usb/gspca/sonixj.c
+++ b/drivers/media/usb/gspca/sonixj.c
@@ -1162,6 +1162,11 @@ 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 2ae03b6..ccc4779 100644 (file)
--- a/drivers/media/usb/gspca/spca1528.c
+++ b/drivers/media/usb/gspca/spca1528.c
@@ -71,6 +71,11 @@ 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 d1ba088..c361024 100644 (file)
--- a/drivers/media/usb/gspca/sq930x.c
+++ b/drivers/media/usb/gspca/sq930x.c
@@ -425,6 +425,11 @@ 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 d0ddfa9..f4a4222 100644 (file)
--- a/drivers/media/usb/gspca/sunplus.c
+++ b/drivers/media/usb/gspca/sunplus.c
@@ -255,6 +255,11 @@ 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 588a847..4cb7c92 100644 (file)
--- a/drivers/media/usb/gspca/vc032x.c
+++ b/drivers/media/usb/gspca/vc032x.c
@@ -2906,6 +2906,11 @@ 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 16b679c..a8350ee 100644 (file)
--- a/drivers/media/usb/gspca/w996Xcf.c
+++ b/drivers/media/usb/gspca/w996Xcf.c
@@ -133,6 +133,11 @@ 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);