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;a=summary
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@xxxxxxxxxxxxxxx> know about it.
>From dbanerje@xxxxxxxxxx Thu Dec 14 18:38:57 2017
From: Debabrata Banerjee <dbanerje@xxxxxxxxxx>
Date: Wed, 13 Dec 2017 15:33:37 -0500
Subject: Fix handling of verdicts after NF_QUEUE
To: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>, "David S . Miller" <davem@xxxxxxxxxxxxx>, netfilter-devel@xxxxxxxxxxxxxxx, coreteam@xxxxxxxxxxxxx, netdev@xxxxxxxxxxxxxxx, stable@xxxxxxxxxxxxxxx, dbanerje@xxxxxxxxxx
Message-ID: <20171213203337.314-1-dbanerje@xxxxxxxxxx>
From: Debabrata Banerjee <dbanerje@xxxxxxxxxx>
[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@xxxxxxxxxx>
Acked-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
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@xxxxxxxxxx are
queue-4.9/fix-handling-of-verdicts-after-nf_queue.patch