All of lore.kernel.org
 help / color / mirror / Atom feed
From: <gregkh@linuxfoundation.org>
To: edumazet@google.com, casey@schaufler-ca.com, davem@davemloft.net,
	gregkh@linuxfoundation.org, james.l.morris@oracle.com
Cc: <stable@vger.kernel.org>, <stable-commits@vger.kernel.org>
Subject: Patch "tcp: add tcp_v4_fill_cb()/tcp_v4_restore_cb()" has been added to the 4.14-stable tree
Date: Thu, 14 Dec 2017 11:47:46 +0100	[thread overview]
Message-ID: <15132484667490@kroah.com> (raw)


This is a note to let you know that I've just added the patch titled

    tcp: add tcp_v4_fill_cb()/tcp_v4_restore_cb()

to the 4.14-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:
     tcp-add-tcp_v4_fill_cb-tcp_v4_restore_cb.patch
and it can be found in the queue-4.14 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 foo@baz Thu Dec 14 11:45:40 CET 2017
From: Eric Dumazet <edumazet@google.com>
Date: Sun, 3 Dec 2017 09:32:59 -0800
Subject: tcp: add tcp_v4_fill_cb()/tcp_v4_restore_cb()

From: Eric Dumazet <edumazet@google.com>


[ Upstream commit eeea10b83a139451130df1594f26710c8fa390c8 ]

James Morris reported kernel stack corruption bug [1] while
running the SELinux testsuite, and bisected to a recent
commit bffa72cf7f9d ("net: sk_buff rbnode reorg")

We believe this commit is fine, but exposes an older bug.

SELinux code runs from tcp_filter() and might send an ICMP,
expecting IP options to be found in skb->cb[] using regular IPCB placement.

We need to defer TCP mangling of skb->cb[] after tcp_filter() calls.

This patch adds tcp_v4_fill_cb()/tcp_v4_restore_cb() in a very
similar way we added them for IPv6.

[1]
[  339.806024] SELinux: failure in selinux_parse_skb(), unable to parse packet
[  339.822505] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff81745af5
[  339.822505]
[  339.852250] CPU: 4 PID: 3642 Comm: client Not tainted 4.15.0-rc1-test #15
[  339.868498] Hardware name: LENOVO 10FGS0VA1L/30BC, BIOS FWKT68A   01/19/2017
[  339.885060] Call Trace:
[  339.896875]  <IRQ>
[  339.908103]  dump_stack+0x63/0x87
[  339.920645]  panic+0xe8/0x248
[  339.932668]  ? ip_push_pending_frames+0x33/0x40
[  339.946328]  ? icmp_send+0x525/0x530
[  339.958861]  ? kfree_skbmem+0x60/0x70
[  339.971431]  __stack_chk_fail+0x1b/0x20
[  339.984049]  icmp_send+0x525/0x530
[  339.996205]  ? netlbl_skbuff_err+0x36/0x40
[  340.008997]  ? selinux_netlbl_err+0x11/0x20
[  340.021816]  ? selinux_socket_sock_rcv_skb+0x211/0x230
[  340.035529]  ? security_sock_rcv_skb+0x3b/0x50
[  340.048471]  ? sk_filter_trim_cap+0x44/0x1c0
[  340.061246]  ? tcp_v4_inbound_md5_hash+0x69/0x1b0
[  340.074562]  ? tcp_filter+0x2c/0x40
[  340.086400]  ? tcp_v4_rcv+0x820/0xa20
[  340.098329]  ? ip_local_deliver_finish+0x71/0x1a0
[  340.111279]  ? ip_local_deliver+0x6f/0xe0
[  340.123535]  ? ip_rcv_finish+0x3a0/0x3a0
[  340.135523]  ? ip_rcv_finish+0xdb/0x3a0
[  340.147442]  ? ip_rcv+0x27c/0x3c0
[  340.158668]  ? inet_del_offload+0x40/0x40
[  340.170580]  ? __netif_receive_skb_core+0x4ac/0x900
[  340.183285]  ? rcu_accelerate_cbs+0x5b/0x80
[  340.195282]  ? __netif_receive_skb+0x18/0x60
[  340.207288]  ? process_backlog+0x95/0x140
[  340.218948]  ? net_rx_action+0x26c/0x3b0
[  340.230416]  ? __do_softirq+0xc9/0x26a
[  340.241625]  ? do_softirq_own_stack+0x2a/0x40
[  340.253368]  </IRQ>
[  340.262673]  ? do_softirq+0x50/0x60
[  340.273450]  ? __local_bh_enable_ip+0x57/0x60
[  340.285045]  ? ip_finish_output2+0x175/0x350
[  340.296403]  ? ip_finish_output+0x127/0x1d0
[  340.307665]  ? nf_hook_slow+0x3c/0xb0
[  340.318230]  ? ip_output+0x72/0xe0
[  340.328524]  ? ip_fragment.constprop.54+0x80/0x80
[  340.340070]  ? ip_local_out+0x35/0x40
[  340.350497]  ? ip_queue_xmit+0x15c/0x3f0
[  340.361060]  ? __kmalloc_reserve.isra.40+0x31/0x90
[  340.372484]  ? __skb_clone+0x2e/0x130
[  340.382633]  ? tcp_transmit_skb+0x558/0xa10
[  340.393262]  ? tcp_connect+0x938/0xad0
[  340.403370]  ? ktime_get_with_offset+0x4c/0xb0
[  340.414206]  ? tcp_v4_connect+0x457/0x4e0
[  340.424471]  ? __inet_stream_connect+0xb3/0x300
[  340.435195]  ? inet_stream_connect+0x3b/0x60
[  340.445607]  ? SYSC_connect+0xd9/0x110
[  340.455455]  ? __audit_syscall_entry+0xaf/0x100
[  340.466112]  ? syscall_trace_enter+0x1d0/0x2b0
[  340.476636]  ? __audit_syscall_exit+0x209/0x290
[  340.487151]  ? SyS_connect+0xe/0x10
[  340.496453]  ? do_syscall_64+0x67/0x1b0
[  340.506078]  ? entry_SYSCALL64_slow_path+0x25/0x25

Fixes: 971f10eca186 ("tcp: better TCP_SKB_CB layout to reduce cache line misses")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: James Morris <james.l.morris@oracle.com>
Tested-by: James Morris <james.l.morris@oracle.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv4/tcp_ipv4.c |   59 +++++++++++++++++++++++++++++++++++-----------------
 net/ipv6/tcp_ipv6.c |   10 +++++---
 2 files changed, 46 insertions(+), 23 deletions(-)

--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1587,6 +1587,34 @@ int tcp_filter(struct sock *sk, struct s
 }
 EXPORT_SYMBOL(tcp_filter);
 
+static void tcp_v4_restore_cb(struct sk_buff *skb)
+{
+	memmove(IPCB(skb), &TCP_SKB_CB(skb)->header.h4,
+		sizeof(struct inet_skb_parm));
+}
+
+static void tcp_v4_fill_cb(struct sk_buff *skb, const struct iphdr *iph,
+			   const struct tcphdr *th)
+{
+	/* This is tricky : We move IPCB at its correct location into TCP_SKB_CB()
+	 * barrier() makes sure compiler wont play fool^Waliasing games.
+	 */
+	memmove(&TCP_SKB_CB(skb)->header.h4, IPCB(skb),
+		sizeof(struct inet_skb_parm));
+	barrier();
+
+	TCP_SKB_CB(skb)->seq = ntohl(th->seq);
+	TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
+				    skb->len - th->doff * 4);
+	TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
+	TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
+	TCP_SKB_CB(skb)->tcp_tw_isn = 0;
+	TCP_SKB_CB(skb)->ip_dsfield = ipv4_get_dsfield(iph);
+	TCP_SKB_CB(skb)->sacked	 = 0;
+	TCP_SKB_CB(skb)->has_rxtstamp =
+			skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
+}
+
 /*
  *	From tcp_input.c
  */
@@ -1627,24 +1655,6 @@ int tcp_v4_rcv(struct sk_buff *skb)
 
 	th = (const struct tcphdr *)skb->data;
 	iph = ip_hdr(skb);
-	/* This is tricky : We move IPCB at its correct location into TCP_SKB_CB()
-	 * barrier() makes sure compiler wont play fool^Waliasing games.
-	 */
-	memmove(&TCP_SKB_CB(skb)->header.h4, IPCB(skb),
-		sizeof(struct inet_skb_parm));
-	barrier();
-
-	TCP_SKB_CB(skb)->seq = ntohl(th->seq);
-	TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
-				    skb->len - th->doff * 4);
-	TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
-	TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
-	TCP_SKB_CB(skb)->tcp_tw_isn = 0;
-	TCP_SKB_CB(skb)->ip_dsfield = ipv4_get_dsfield(iph);
-	TCP_SKB_CB(skb)->sacked	 = 0;
-	TCP_SKB_CB(skb)->has_rxtstamp =
-			skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
-
 lookup:
 	sk = __inet_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th), th->source,
 			       th->dest, sdif, &refcounted);
@@ -1675,14 +1685,19 @@ process:
 		sock_hold(sk);
 		refcounted = true;
 		nsk = NULL;
-		if (!tcp_filter(sk, skb))
+		if (!tcp_filter(sk, skb)) {
+			th = (const struct tcphdr *)skb->data;
+			iph = ip_hdr(skb);
+			tcp_v4_fill_cb(skb, iph, th);
 			nsk = tcp_check_req(sk, skb, req, false);
+		}
 		if (!nsk) {
 			reqsk_put(req);
 			goto discard_and_relse;
 		}
 		if (nsk == sk) {
 			reqsk_put(req);
+			tcp_v4_restore_cb(skb);
 		} else if (tcp_child_process(sk, nsk, skb)) {
 			tcp_v4_send_reset(nsk, skb);
 			goto discard_and_relse;
@@ -1708,6 +1723,7 @@ process:
 		goto discard_and_relse;
 	th = (const struct tcphdr *)skb->data;
 	iph = ip_hdr(skb);
+	tcp_v4_fill_cb(skb, iph, th);
 
 	skb->dev = NULL;
 
@@ -1738,6 +1754,8 @@ no_tcp_socket:
 	if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
 		goto discard_it;
 
+	tcp_v4_fill_cb(skb, iph, th);
+
 	if (tcp_checksum_complete(skb)) {
 csum_error:
 		__TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
@@ -1764,6 +1782,8 @@ do_time_wait:
 		goto discard_it;
 	}
 
+	tcp_v4_fill_cb(skb, iph, th);
+
 	if (tcp_checksum_complete(skb)) {
 		inet_twsk_put(inet_twsk(sk));
 		goto csum_error;
@@ -1780,6 +1800,7 @@ do_time_wait:
 		if (sk2) {
 			inet_twsk_deschedule_put(inet_twsk(sk));
 			sk = sk2;
+			tcp_v4_restore_cb(skb);
 			refcounted = false;
 			goto process;
 		}
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1448,7 +1448,6 @@ process:
 		struct sock *nsk;
 
 		sk = req->rsk_listener;
-		tcp_v6_fill_cb(skb, hdr, th);
 		if (tcp_v6_inbound_md5_hash(sk, skb)) {
 			sk_drops_add(sk, skb);
 			reqsk_put(req);
@@ -1461,8 +1460,12 @@ process:
 		sock_hold(sk);
 		refcounted = true;
 		nsk = NULL;
-		if (!tcp_filter(sk, skb))
+		if (!tcp_filter(sk, skb)) {
+			th = (const struct tcphdr *)skb->data;
+			hdr = ipv6_hdr(skb);
+			tcp_v6_fill_cb(skb, hdr, th);
 			nsk = tcp_check_req(sk, skb, req, false);
+		}
 		if (!nsk) {
 			reqsk_put(req);
 			goto discard_and_relse;
@@ -1486,8 +1489,6 @@ process:
 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
 		goto discard_and_relse;
 
-	tcp_v6_fill_cb(skb, hdr, th);
-
 	if (tcp_v6_inbound_md5_hash(sk, skb))
 		goto discard_and_relse;
 
@@ -1495,6 +1496,7 @@ process:
 		goto discard_and_relse;
 	th = (const struct tcphdr *)skb->data;
 	hdr = ipv6_hdr(skb);
+	tcp_v6_fill_cb(skb, hdr, th);
 
 	skb->dev = NULL;
 


Patches currently in stable-queue which might be from edumazet@google.com are

queue-4.14/tcp-add-tcp_v4_fill_cb-tcp_v4_restore_cb.patch
queue-4.14/net-thunderx-fix-tcp-udp-checksum-offload-for-ipv6-pkts.patch
queue-4.14/tcp-remove-buggy-call-to-tcp_v6_restore_cb.patch
queue-4.14/net-packet-fix-a-race-in-packet_bind-and-packet_notifier.patch
queue-4.14/tcp-use-ipcb-instead-of-tcp_skb_cb-in-inet_exact_dif_match.patch
queue-4.14/net-thunderx-fix-tcp-udp-checksum-offload-for-ipv4-pkts.patch
queue-4.14/packet-fix-crash-in-fanout_demux_rollover.patch
queue-4.14/net-remove-hlist_nulls_add_tail_rcu.patch
queue-4.14/tcp-when-scheduling-tlp-time-of-rto-should-account-for-current-ack.patch
queue-4.14/tcp-dccp-block-bh-before-arming-time_wait-timer.patch
queue-4.14/tcp-use-current-time-in-tcp_rcv_space_adjust.patch

                 reply	other threads:[~2017-12-14 10:48 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=15132484667490@kroah.com \
    --to=gregkh@linuxfoundation.org \
    --cc=casey@schaufler-ca.com \
    --cc=davem@davemloft.net \
    --cc=edumazet@google.com \
    --cc=james.l.morris@oracle.com \
    --cc=stable-commits@vger.kernel.org \
    --cc=stable@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.