This is a note to let you know that I've just added the patch titled
Fix handling of verdicts after NF_QUEUE
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: fix-handling-of-verdicts-after-nf_queue.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@vger.kernel.org know about it.
From dbanerje@akamai.com Thu Dec 14 18:38:57 2017
From: Debabrata Banerjee dbanerje@akamai.com Date: Wed, 13 Dec 2017 15:33:37 -0500 Subject: Fix handling of verdicts after NF_QUEUE To: Pablo Neira Ayuso pablo@netfilter.org Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org, "David S . Miller" davem@davemloft.net, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, stable@vger.kernel.org, dbanerje@akamai.com Message-ID: 20171213203337.314-1-dbanerje@akamai.com
From: Debabrata Banerjee dbanerje@akamai.com
[This fix is only needed for v4.9 stable since v4.10+ does not have the issue]
A verdict of NF_STOLEN after NF_QUEUE will cause an incorrect return value and a potential kernel panic via double free of skb's
This was broken by commit 7034b566a4e7 ("netfilter: fix nf_queue handling") and subsequently fixed in v4.10 by commit c63cbc460419 ("netfilter: use switch() to handle verdict cases from nf_hook_slow()"). However that commit cannot be cleanly cherry-picked to v4.9
Signed-off-by: Debabrata Banerjee dbanerje@akamai.com Acked-by: Pablo Neira Ayuso pablo@netfilter.org
--- net/netfilter/core.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/net/netfilter/core.c +++ b/net/netfilter/core.c @@ -364,6 +364,11 @@ next_hook: ret = nf_queue(skb, state, &entry, verdict); if (ret == 1 && entry) goto next_hook; + } else { + /* Implicit handling for NF_STOLEN, as well as any other + * non conventional verdicts. + */ + ret = 0; } return ret; }
Patches currently in stable-queue which might be from dbanerje@akamai.com are
queue-4.9/fix-handling-of-verdicts-after-nf_queue.patch