From 8a10da264663f97ad8b5c85343274ad903b32196 Mon Sep 17 00:00:00 2001 From: Alexey Khoroshilov Date: Wed, 4 Sep 2013 00:37:17 +0400 Subject: [PATCH] rtl8187: fix use after free on failure path in rtl8187_init_urbs() In case of __dev_alloc_skb() failure rtl8187_init_urbs() calls usb_free_urb(entry) where 'entry' can points to urb allocated at the previous iteration. That means refcnt will be decremented incorrectly and the urb can be used after memory deallocation. The patch fixes the issue and implements error handling of init_urbs in rtl8187_start(). Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov Signed-off-by: John W. Linville --- drivers/net/wireless/rtl818x/rtl8187/dev.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/net/wireless/rtl818x/rtl8187/dev.c b/drivers/net/wireless/rtl818x/rtl8187/dev.c index 841fb9dfc9da..9a6edb0c014e 100644 --- a/drivers/net/wireless/rtl818x/rtl8187/dev.c +++ b/drivers/net/wireless/rtl818x/rtl8187/dev.c @@ -438,17 +438,16 @@ static int rtl8187_init_urbs(struct ieee80211_hw *dev) skb_queue_tail(&priv->rx_queue, skb); usb_anchor_urb(entry, &priv->anchored); ret = usb_submit_urb(entry, GFP_KERNEL); + usb_put_urb(entry); if (ret) { skb_unlink(skb, &priv->rx_queue); usb_unanchor_urb(entry); goto err; } - usb_free_urb(entry); } return ret; err: - usb_free_urb(entry); kfree_skb(skb); usb_kill_anchored_urbs(&priv->anchored); return ret; @@ -956,8 +955,12 @@ static int rtl8187_start(struct ieee80211_hw *dev) (RETRY_COUNT << 8 /* short retry limit */) | (RETRY_COUNT << 0 /* long retry limit */) | (7 << 21 /* MAX TX DMA */)); - rtl8187_init_urbs(dev); - rtl8187b_init_status_urb(dev); + ret = rtl8187_init_urbs(dev); + if (ret) + goto rtl8187_start_exit; + ret = rtl8187b_init_status_urb(dev); + if (ret) + usb_kill_anchored_urbs(&priv->anchored); goto rtl8187_start_exit; } @@ -966,7 +969,9 @@ static int rtl8187_start(struct ieee80211_hw *dev) rtl818x_iowrite32(priv, &priv->map->MAR[0], ~0); rtl818x_iowrite32(priv, &priv->map->MAR[1], ~0); - rtl8187_init_urbs(dev); + ret = rtl8187_init_urbs(dev); + if (ret) + goto rtl8187_start_exit; reg = RTL818X_RX_CONF_ONLYERLPKT | RTL818X_RX_CONF_RX_AUTORESETPHY | -- 2.20.1