From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [Bug 42809] New: kernel panic when receiving an ipsec packet Date: Thu, 23 Feb 2012 15:36:26 +0100 Message-ID: <1330007786.15610.26.camel@edumazet-laptop> References: <20120222092056.5fca788b@nehalam.linuxnetplumber.net> <4F4528CE.7080702@linuxsystems.it> <4F458F82.3060808@linuxsystems.it> <1329961083.15610.2.camel@edumazet-laptop> <4F459E37.9010507@linuxsystems.it> <1329962785.15610.8.camel@edumazet-laptop> <4F46430D.3060802@linuxsystems.it> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Linux Networking Developer Mailing List , openadsl-users@lists.sourceforge.net, openadsl-devel@lists.sourceforge.net, 660804@bugs.debian.org, support@traverse.com.au, support@rocksolidelectronics.com To: =?ISO-8859-1?Q?Niccol=F2?= Belli , David Miller Return-path: Received: from mail-we0-f174.google.com ([74.125.82.174]:57016 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753084Ab2BWOge (ORCPT ); Thu, 23 Feb 2012 09:36:34 -0500 Received: by werb13 with SMTP id b13so789898wer.19 for ; Thu, 23 Feb 2012 06:36:33 -0800 (PST) In-Reply-To: <4F46430D.3060802@linuxsystems.it> Sender: netdev-owner@vger.kernel.org List-ID: > Your patch does solve the problem, thanks! >=20 Thanks for testing. Here is the official patch I submit for review then. [PATCH] ipsec: be careful of non existing mac headers Nicollo Belli reported ipsec crashes in case we handle a frame without mac header (atm in his case) Before copying mac header, better make sure it is present. Bugzilla reference: https://bugzilla.kernel.org/show_bug.cgi?id=3D4280= 9 Reported-by: Niccol=C3=B2 Belli Tested-by: Niccol=C3=B2 Belli Signed-off-by: Eric Dumazet --- net/ipv4/xfrm4_mode_beet.c | 9 +++++---- net/ipv4/xfrm4_mode_tunnel.c | 10 ++++++---- net/ipv6/xfrm6_mode_beet.c | 9 +++++---- net/ipv6/xfrm6_mode_tunnel.c | 10 ++++++---- 4 files changed, 22 insertions(+), 16 deletions(-) diff --git a/net/ipv4/xfrm4_mode_beet.c b/net/ipv4/xfrm4_mode_beet.c index 6341818..d3451f6 100644 --- a/net/ipv4/xfrm4_mode_beet.c +++ b/net/ipv4/xfrm4_mode_beet.c @@ -111,10 +111,11 @@ static int xfrm4_beet_input(struct xfrm_state *x,= struct sk_buff *skb) skb_push(skb, sizeof(*iph)); skb_reset_network_header(skb); =20 - memmove(skb->data - skb->mac_len, skb_mac_header(skb), - skb->mac_len); - skb_set_mac_header(skb, -skb->mac_len); - + if (skb_mac_header_was_set(skb)) { + memmove(skb->data - skb->mac_len, skb_mac_header(skb), + skb->mac_len); + skb_set_mac_header(skb, -skb->mac_len); + } xfrm4_beet_make_header(skb); =20 iph =3D ip_hdr(skb); diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.= c index 534972e..a646f30 100644 --- a/net/ipv4/xfrm4_mode_tunnel.c +++ b/net/ipv4/xfrm4_mode_tunnel.c @@ -66,7 +66,6 @@ static int xfrm4_mode_tunnel_output(struct xfrm_state= *x, struct sk_buff *skb) =20 static int xfrm4_mode_tunnel_input(struct xfrm_state *x, struct sk_buf= f *skb) { - const unsigned char *old_mac; int err =3D -EINVAL; =20 if (XFRM_MODE_SKB_CB(skb)->protocol !=3D IPPROTO_IPIP) @@ -84,9 +83,12 @@ static int xfrm4_mode_tunnel_input(struct xfrm_state= *x, struct sk_buff *skb) if (!(x->props.flags & XFRM_STATE_NOECN)) ipip_ecn_decapsulate(skb); =20 - old_mac =3D skb_mac_header(skb); - skb_set_mac_header(skb, -skb->mac_len); - memmove(skb_mac_header(skb), old_mac, skb->mac_len); + if (skb_mac_header_was_set(skb)) { + const unsigned char *old_mac =3D skb_mac_header(skb); + + skb_set_mac_header(skb, -skb->mac_len); + memmove(skb_mac_header(skb), old_mac, skb->mac_len); + } skb_reset_network_header(skb); err =3D 0; =20 diff --git a/net/ipv6/xfrm6_mode_beet.c b/net/ipv6/xfrm6_mode_beet.c index a81ce94..74c4b92 100644 --- a/net/ipv6/xfrm6_mode_beet.c +++ b/net/ipv6/xfrm6_mode_beet.c @@ -80,7 +80,6 @@ static int xfrm6_beet_output(struct xfrm_state *x, st= ruct sk_buff *skb) static int xfrm6_beet_input(struct xfrm_state *x, struct sk_buff *skb) { struct ipv6hdr *ip6h; - const unsigned char *old_mac; int size =3D sizeof(struct ipv6hdr); int err; =20 @@ -91,10 +90,12 @@ static int xfrm6_beet_input(struct xfrm_state *x, s= truct sk_buff *skb) __skb_push(skb, size); skb_reset_network_header(skb); =20 - old_mac =3D skb_mac_header(skb); - skb_set_mac_header(skb, -skb->mac_len); - memmove(skb_mac_header(skb), old_mac, skb->mac_len); + if (skb_mac_header_was_set(skb)) { + const unsigned char *old_mac =3D skb_mac_header(skb); =20 + skb_set_mac_header(skb, -skb->mac_len); + memmove(skb_mac_header(skb), old_mac, skb->mac_len); + } xfrm6_beet_make_header(skb); =20 ip6h =3D ipv6_hdr(skb); diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.= c index 261e6e6..edb7091 100644 --- a/net/ipv6/xfrm6_mode_tunnel.c +++ b/net/ipv6/xfrm6_mode_tunnel.c @@ -63,7 +63,6 @@ static int xfrm6_mode_tunnel_output(struct xfrm_state= *x, struct sk_buff *skb) static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buf= f *skb) { int err =3D -EINVAL; - const unsigned char *old_mac; =20 if (XFRM_MODE_SKB_CB(skb)->protocol !=3D IPPROTO_IPV6) goto out; @@ -80,9 +79,12 @@ static int xfrm6_mode_tunnel_input(struct xfrm_state= *x, struct sk_buff *skb) if (!(x->props.flags & XFRM_STATE_NOECN)) ipip6_ecn_decapsulate(skb); =20 - old_mac =3D skb_mac_header(skb); - skb_set_mac_header(skb, -skb->mac_len); - memmove(skb_mac_header(skb), old_mac, skb->mac_len); + if (skb_mac_header_was_set(skb)) { + const unsigned char *old_mac =3D skb_mac_header(skb); + + skb_set_mac_header(skb, -skb->mac_len); + memmove(skb_mac_header(skb), old_mac, skb->mac_len); + } skb_reset_network_header(skb); err =3D 0; =20