From d2f33830a8046f14474120b4dae4d71ee668ec18 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Fri, 16 Aug 2019 03:38:13 -0300 Subject: media: gspca: zero usb_buf on error [ 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@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 Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/usb/gspca/sonixj.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/media/usb/gspca/sonixj.c') diff --git a/drivers/media/usb/gspca/sonixj.c b/drivers/media/usb/gspca/sonixj.c index 5eeaf16ac5e8..c53002a5ccb7 100644 --- a/drivers/media/usb/gspca/sonixj.c +++ b/drivers/media/usb/gspca/sonixj.c @@ -1170,6 +1170,11 @@ 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); } } -- cgit v1.2.3