For fixing syzbot "KMSAN: uninit-value in digitv_rc_query" In scenario testing for syzbot, failure reading from digitv_ctrl_msg() [1]. Eg: [ 91.846657][ T3844] dvb-usb: bulk message failed: -22 (7/0) digitv_rc_query() always return 0. But in this case a wrong thing happens. Reported-by: syzbot+6bf9606ee955b646c0e1@xxxxxxxxxxxxxxxxxxxxxxxxx Tested-by: syzbot+6bf9606ee955b646c0e1@xxxxxxxxxxxxxxxxxxxxxxxxx [1]: https://syzkaller.appspot.com/text?tag=CrashLog&x=16860a63600000 [2]: https://groups.google.com/d/msg/syzkaller-bugs/-TXIJAZ0J9Q/T4PEUQoeAQAJ Signed-off-by: Phong Tran <tranmanphong@xxxxxxxxx> --- drivers/media/usb/dvb-usb/digitv.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/media/usb/dvb-usb/digitv.c b/drivers/media/usb/dvb-usb/digitv.c index dd5bb230cec1..61bc8945e6b9 100644 --- a/drivers/media/usb/dvb-usb/digitv.c +++ b/drivers/media/usb/dvb-usb/digitv.c @@ -231,17 +231,21 @@ static struct rc_map_table rc_map_digitv_table[] = { static int digitv_rc_query(struct dvb_usb_device *d, u32 *event, int *state) { int i; - u8 key[5]; + u8 key[5] = { 0 }; u8 b[4] = { 0 }; + int ret; *event = 0; *state = REMOTE_NO_KEY_PRESSED; - digitv_ctrl_msg(d,USB_READ_REMOTE,0,NULL,0,&key[1],4); - + ret = digitv_ctrl_msg(d, USB_READ_REMOTE, 0, NULL, 0, &key[1], 4); + if (ret < 0) + return ret; /* Tell the device we've read the remote. Not sure how necessary this is, but the Nebula SDK does it. */ - digitv_ctrl_msg(d,USB_WRITE_REMOTE,0,b,4,NULL,0); + ret = digitv_ctrl_msg(d, USB_WRITE_REMOTE, 0, b, 4, NULL, 0); + if (ret < 0) + return ret; /* if something is inside the buffer, simulate key press */ if (key[1] != 0) -- 2.20.1
