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. Signed-off-by: Hans Verkuil <hverkuil-ci...@xs4all.nl> Reported-and-tested-by: syzbot+1a35278dd0ebfb3a0...@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+397fd082ce5143e2f...@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+06ddf1788cfd048c5...@syzkaller.appspotmail.com --- Changes in v2: use USB_BUF_SZ instead of sizeof(gspca_dev->usb_buf) since usb_buf is a pointer. --- diff --git a/drivers/media/usb/gspca/konica.c b/drivers/media/usb/gspca/konica.c index d8e40137a204..53db9a2895ea 100644 --- 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 59649704beba..db3e1657670b 100644 --- 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 cfb1f53bc17e..f417dfc0b872 100644 --- 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 56521c991db4..185c1f10fb30 100644 --- 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 867f860a9650..91efc650cf76 100644 --- 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 061deee138c3..e087cfb5980b 100644 --- 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 b43f89fee6c1..490af88e88ac 100644 --- 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 046fc2c2a135..4d655e2da9cb 100644 --- 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 50a6c8425827..acf931a2bf1f 100644 --- 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 2ae03b60163f..ec1811895f85 100644 --- 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 d1ba0888d798..cd9bf31ed437 100644 --- 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 d0ddfa957ca9..0648d0db5515 100644 --- 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 588a847ea483..e652a6becb3e 100644 --- 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 16b679c2de21..a8350ee9712f 100644 --- 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);
