This is a note to let you know that I've just added the patch titled net: core: Prevent from dereferencing null pointer when releasing SKB to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-core-prevent-from-dereferencing-null-pointer-when-releasing-skb.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Thu Oct 5 10:28:31 CEST 2017 From: Myungho Jung <mhjungk@xxxxxxxxx> Date: Tue, 25 Apr 2017 11:58:15 -0700 Subject: net: core: Prevent from dereferencing null pointer when releasing SKB From: Myungho Jung <mhjungk@xxxxxxxxx> [ Upstream commit 9899886d5e8ec5b343b1efe44f185a0e68dc6454 ] 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 <mhjungk@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/core/dev.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2355,6 +2355,9 @@ void __dev_kfree_skb_irq(struct sk_buff { unsigned long flags; + if (unlikely(!skb)) + return; + if (likely(atomic_read(&skb->users) == 1)) { smp_rmb(); atomic_set(&skb->users, 0); Patches currently in stable-queue which might be from mhjungk@xxxxxxxxx are queue-4.9/net-core-prevent-from-dereferencing-null-pointer-when-releasing-skb.patch