From d18ca5b7ceca0e9674cb4bb2ed476b0fcbb23ba2 Mon Sep 17 00:00:00 2001 From: Antti Palosaari Date: Tue, 6 Oct 2015 00:22:23 -0300 Subject: [PATCH] [media] rtl28xxu: fix control message flaws Add lock to prevent concurrent access for control message as control message function uses shared buffer. Without the lock there may be remote control polling which messes the buffer causing IO errors. Increase buffer size and add check for maximum supported message length. Link: https://bugzilla.kernel.org/show_bug.cgi?id=103391 Fixes: c56222a6b25c ("[media] rtl28xxu: move usb buffers to state") Cc: # 4.0+ Signed-off-by: Antti Palosaari --- drivers/media/usb/dvb-usb-v2/rtl28xxu.c | 15 +++++++++++++-- drivers/media/usb/dvb-usb-v2/rtl28xxu.h | 2 +- 2 files changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c index c3cac4c..197a4f2 100644 --- a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c +++ b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c @@ -34,6 +34,14 @@ static int rtl28xxu_ctrl_msg(struct dvb_usb_device *d, struct rtl28xxu_req *req) unsigned int pipe; u8 requesttype; + mutex_lock(&d->usb_mutex); + + if (req->size > sizeof(dev->buf)) { + dev_err(&d->intf->dev, "too large message %u\n", req->size); + ret = -EINVAL; + goto err_mutex_unlock; + } + if (req->index & CMD_WR_FLAG) { /* write */ memcpy(dev->buf, req->data, req->size); @@ -50,14 +58,17 @@ static int rtl28xxu_ctrl_msg(struct dvb_usb_device *d, struct rtl28xxu_req *req) dvb_usb_dbg_usb_control_msg(d->udev, 0, requesttype, req->value, req->index, dev->buf, req->size); if (ret < 0) - goto err; + goto err_mutex_unlock; /* read request, copy returned data to return buf */ if (requesttype == (USB_TYPE_VENDOR | USB_DIR_IN)) memcpy(req->data, dev->buf, req->size); + mutex_unlock(&d->usb_mutex); + return 0; -err: +err_mutex_unlock: + mutex_unlock(&d->usb_mutex); dev_dbg(&d->intf->dev, "failed=%d\n", ret); return ret; } diff --git a/drivers/media/usb/dvb-usb-v2/rtl28xxu.h b/drivers/media/usb/dvb-usb-v2/rtl28xxu.h index 9f6115a..1380629 100644 --- a/drivers/media/usb/dvb-usb-v2/rtl28xxu.h +++ b/drivers/media/usb/dvb-usb-v2/rtl28xxu.h @@ -71,7 +71,7 @@ struct rtl28xxu_dev { - u8 buf[28]; + u8 buf[128]; u8 chip_id; u8 tuner; char *tuner_name; -- 2.7.4