This is a note to let you know that we have just queued up the patch titled Subject: netfilter: Fix kernel panic with REDIRECT target. to the 2.6.23-stable tree. Its filename is netfilter-fix-kernel-panic-with-redirect-target.patch A git repo of this tree can be found at http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary >From stable-bounces@xxxxxxxxxxxxxxxx Wed Nov 28 00:57:19 2007 From: Evgeniy Polyakov <johnpol@xxxxxxxxxxx> Date: Wed, 28 Nov 2007 09:56:54 +0100 Subject: netfilter: Fix kernel panic with REDIRECT target. To: stable@xxxxxxxxxx Cc: Netfilter Development Mailinglist <netfilter-devel@xxxxxxxxxxxxxxx>, "David S. Miller" <davem@xxxxxxxxxxxxx> Message-ID: <474D2D56.9090503@xxxxxxxxx> From: Evgeniy Polyakov <johnpol@xxxxxxxxxxx> This patch fixes a NAT regression in 2.6.23, resulting in a crash when a connection is NATed and matches a conntrack helper after NAT. Please apply, thanks. [NETFILTER]: Fix kernel panic with REDIRECT target. Upstream commit 1f305323ff5b9ddc1a4346d36072bcdb58f3f68a When connection tracking entry (nf_conn) is about to copy itself it can have some of its extension users (like nat) as being already freed and thus not required to be copied. Actually looking at this function I suspect it was copied from nf_nat_setup_info() and thus bug was introduced. Report and testing from David <david@xxxxxxxxxxxxxxx>. [ Patrick McHardy states: I now understand whats happening: - new connection is allocated without helper - connection is REDIRECTed to localhost - nf_nat_setup_info adds NAT extension, but doesn't initialize it yet - nf_conntrack_alter_reply performs a helper lookup based on the new tuple, finds the SIP helper and allocates a helper extension, causing reallocation because of too little space - nf_nat_move_storage is called with the uninitialized nat extension So your fix is entirely correct, thanks a lot :) ] Signed-off-by: Evgeniy Polyakov <johnpol@xxxxxxxxxxx> Acked-by: Patrick McHardy <kaber@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx> --- net/ipv4/netfilter/nf_nat_core.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) --- a/net/ipv4/netfilter/nf_nat_core.c +++ b/net/ipv4/netfilter/nf_nat_core.c @@ -607,13 +607,10 @@ static void nf_nat_move_storage(struct n struct nf_conn_nat *new_nat = nf_ct_ext_find(conntrack, NF_CT_EXT_NAT); struct nf_conn_nat *old_nat = (struct nf_conn_nat *)old; struct nf_conn *ct = old_nat->ct; - unsigned int srchash; - if (!(ct->status & IPS_NAT_DONE_MASK)) + if (!ct || !(ct->status & IPS_NAT_DONE_MASK)) return; - srchash = hash_by_src(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); - write_lock_bh(&nf_nat_lock); hlist_replace_rcu(&old_nat->bysource, &new_nat->bysource); new_nat->ct = ct; Patches currently in stable-queue which might be from johnpol@xxxxxxxxxxx are queue-2.6.23/netfilter-fix-null-pointer-dereference-in-nf_nat_move_storage.patch queue-2.6.23/netfilter-fix-kernel-panic-with-redirect-target.patch - To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html