From mboxrd@z Thu Jan 1 00:00:00 1970 From: Myungho Jung Subject: [PATCH] p54: Prevent from dereferencing null pointer when releasing SKB Date: Thu, 20 Apr 2017 11:25:23 -0700 Message-ID: <1492712723-9350-1-git-send-email-mhjungk@gmail.com> Cc: netdev@vger.kernel.org To: edumazet@google.com Return-path: Received: from mail-oi0-f65.google.com ([209.85.218.65]:34189 "EHLO mail-oi0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S971290AbdDTSZZ (ORCPT ); Thu, 20 Apr 2017 14:25:25 -0400 Received: by mail-oi0-f65.google.com with SMTP id y11so10025222oie.1 for ; Thu, 20 Apr 2017 11:25:25 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Added NULL check to make __dev_kfree_skb_irq consistent with kfree family of functions. Link: https://bugzilla.kernel.org/show_bug.cgi?id=195289 Signed-off-by: Myungho Jung --- net/core/dev.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/core/dev.c b/net/core/dev.c index 7869ae3..22be2a6 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2450,6 +2450,9 @@ void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason) { unsigned long flags; + if (unlikely(!skb)) + return; + if (likely(atomic_read(&skb->users) == 1)) { smp_rmb(); atomic_set(&skb->users, 0); -- 2.7.4