From 22b68b93ae2506bd56ee3bf232a51bc8ab955b56 Mon Sep 17 00:00:00 2001 From: Larry Finger Date: Mon, 19 Dec 2016 20:38:12 -0600 Subject: [PATCH] rtlwifi: Fix kernel oops introduced with commit e49656147359 With commit e49656147359 {"rtlwifi: Use dev_kfree_skb_irq instead of kfree_skb"), the method used to free an skb was changed because the kfree_skb() was inside a spinlock. What was forgotten is that kfree_skb() guards against a NULL value for the argument. Routine dev_kfree_skb_irq() does not, and a test is needed to prevent kernel panics. Fixes: e49656147359 ("rtlwifi: Use dev_kfree_skb_irq instead of kfree_skb") Signed-off-by: Larry Finger Cc: Stable # 4.9+ Cc: Wei Yongjun Signed-off-by: Kalle Valo --- drivers/net/wireless/realtek/rtlwifi/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/realtek/rtlwifi/core.c b/drivers/net/wireless/realtek/rtlwifi/core.c index 2caa4ad04dba..ded1493fee9c 100644 --- a/drivers/net/wireless/realtek/rtlwifi/core.c +++ b/drivers/net/wireless/realtek/rtlwifi/core.c @@ -1829,7 +1829,8 @@ bool rtl_cmd_send_packet(struct ieee80211_hw *hw, struct sk_buff *skb) spin_lock_irqsave(&rtlpriv->locks.irq_th_lock, flags); pskb = __skb_dequeue(&ring->queue); - dev_kfree_skb_irq(pskb); + if (pskb) + dev_kfree_skb_irq(pskb); /*this is wrong, fill_tx_cmddesc needs update*/ pdesc = &ring->desc[0];