From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org,
syzbot+9adb4b567003cac781f0@syzkaller.appspotmail.com,
Willem de Bruijn <willemb@google.com>,
"David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.9 04/33] ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pull
Date: Fri, 27 Jul 2018 12:08:45 +0200 [thread overview]
Message-ID: <20180727100827.833022084@linuxfoundation.org> (raw)
In-Reply-To: <20180727100827.665729981@linuxfoundation.org>
4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Willem de Bruijn <willemb@google.com>
[ Upstream commit 2efd4fca703a6707cad16ab486eaab8fc7f0fd49 ]
Syzbot reported a read beyond the end of the skb head when returning
IPV6_ORIGDSTADDR:
BUG: KMSAN: kernel-infoleak in put_cmsg+0x5ef/0x860 net/core/scm.c:242
CPU: 0 PID: 4501 Comm: syz-executor128 Not tainted 4.17.0+ #9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x185/0x1d0 lib/dump_stack.c:113
kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:1125
kmsan_internal_check_memory+0x138/0x1f0 mm/kmsan/kmsan.c:1219
kmsan_copy_to_user+0x7a/0x160 mm/kmsan/kmsan.c:1261
copy_to_user include/linux/uaccess.h:184 [inline]
put_cmsg+0x5ef/0x860 net/core/scm.c:242
ip6_datagram_recv_specific_ctl+0x1cf3/0x1eb0 net/ipv6/datagram.c:719
ip6_datagram_recv_ctl+0x41c/0x450 net/ipv6/datagram.c:733
rawv6_recvmsg+0x10fb/0x1460 net/ipv6/raw.c:521
[..]
This logic and its ipv4 counterpart read the destination port from
the packet at skb_transport_offset(skb) + 4.
With MSG_MORE and a local SOCK_RAW sender, syzbot was able to cook a
packet that stores headers exactly up to skb_transport_offset(skb) in
the head and the remainder in a frag.
Call pskb_may_pull before accessing the pointer to ensure that it lies
in skb head.
Link: http://lkml.kernel.org/r/CAF=yD-LEJwZj5a1-bAAj2Oy_hKmGygV6rsJ_WOrAYnv-fnayiQ@mail.gmail.com
Reported-by: syzbot+9adb4b567003cac781f0@syzkaller.appspotmail.com
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ipv4/ip_sockglue.c | 7 +++++--
net/ipv6/datagram.c | 7 +++++--
2 files changed, 10 insertions(+), 4 deletions(-)
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -135,15 +135,18 @@ static void ip_cmsg_recv_dstaddr(struct
{
struct sockaddr_in sin;
const struct iphdr *iph = ip_hdr(skb);
- __be16 *ports = (__be16 *)skb_transport_header(skb);
+ __be16 *ports;
+ int end;
- if (skb_transport_offset(skb) + 4 > (int)skb->len)
+ end = skb_transport_offset(skb) + 4;
+ if (end > 0 && !pskb_may_pull(skb, end))
return;
/* All current transport protocols have the port numbers in the
* first four bytes of the transport header and this function is
* written with this assumption in mind.
*/
+ ports = (__be16 *)skb_transport_header(skb);
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = iph->daddr;
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -694,13 +694,16 @@ void ip6_datagram_recv_specific_ctl(stru
}
if (np->rxopt.bits.rxorigdstaddr) {
struct sockaddr_in6 sin6;
- __be16 *ports = (__be16 *) skb_transport_header(skb);
+ __be16 *ports;
+ int end;
- if (skb_transport_offset(skb) + 4 <= (int)skb->len) {
+ end = skb_transport_offset(skb) + 4;
+ if (end <= 0 || pskb_may_pull(skb, end)) {
/* All current transport protocols have the port numbers in the
* first four bytes of the transport header and this function is
* written with this assumption in mind.
*/
+ ports = (__be16 *)skb_transport_header(skb);
sin6.sin6_family = AF_INET6;
sin6.sin6_addr = ipv6_hdr(skb)->daddr;
next prev parent reply other threads:[~2018-07-27 10:10 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-27 10:08 [PATCH 4.9 00/33] 4.9.116-stable review Greg Kroah-Hartman
2018-07-27 10:08 ` [PATCH 4.9 01/33] MIPS: ath79: fix register address in ath79_ddr_wb_flush() Greg Kroah-Hartman
2018-07-27 10:08 ` [PATCH 4.9 02/33] MIPS: Fix off-by-one in pci_resource_to_user() Greg Kroah-Hartman
2018-07-27 10:08 ` [PATCH 4.9 03/33] ip: hash fragments consistently Greg Kroah-Hartman
2018-07-27 10:08 ` Greg Kroah-Hartman [this message]
2018-07-27 10:08 ` [PATCH 4.9 05/33] net/mlx4_core: Save the qpn from the input modifier in RST2INIT wrapper Greg Kroah-Hartman
2018-07-27 10:08 ` [PATCH 4.9 06/33] net: skb_segment() should not return NULL Greg Kroah-Hartman
2018-07-27 10:08 ` [PATCH 4.9 07/33] net/mlx5: Adjust clock overflow work period Greg Kroah-Hartman
2018-07-27 10:08 ` [PATCH 4.9 08/33] net/mlx5e: Dont allow aRFS for encapsulated packets Greg Kroah-Hartman
2018-07-27 10:08 ` [PATCH 4.9 09/33] net/mlx5e: Fix quota counting in aRFS expire flow Greg Kroah-Hartman
2018-07-27 10:08 ` [PATCH 4.9 10/33] multicast: do not restore deleted record source filter mode to new one Greg Kroah-Hartman
2018-07-27 10:08 ` [PATCH 4.9 11/33] net: phy: consider PHY_IGNORE_INTERRUPT in phy_start_aneg_priv Greg Kroah-Hartman
2018-07-27 10:08 ` [PATCH 4.9 12/33] rtnetlink: add rtnl_link_state check in rtnl_configure_link Greg Kroah-Hartman
2018-07-27 10:08 ` [PATCH 4.9 13/33] tcp: fix dctcp delayed ACK schedule Greg Kroah-Hartman
2018-07-27 10:08 ` [PATCH 4.9 14/33] tcp: helpers to send special DCTCP ack Greg Kroah-Hartman
2018-07-27 10:08 ` [PATCH 4.9 15/33] tcp: do not cancel delay-AcK on DCTCP special ACK Greg Kroah-Hartman
2018-07-27 10:08 ` [PATCH 4.9 16/33] tcp: do not delay ACK in DCTCP upon CE status change Greg Kroah-Hartman
2018-07-27 10:08 ` [PATCH 4.9 17/33] tcp: free batches of packets in tcp_prune_ofo_queue() Greg Kroah-Hartman
2018-07-27 10:08 ` [PATCH 4.9 18/33] tcp: avoid collapses in tcp_prune_queue() if possible Greg Kroah-Hartman
2018-07-27 10:09 ` [PATCH 4.9 19/33] tcp: detect malicious patterns in tcp_collapse_ofo_queue() Greg Kroah-Hartman
2018-07-27 10:09 ` [PATCH 4.9 20/33] tcp: call tcp_drop() from tcp_data_queue_ofo() Greg Kroah-Hartman
2018-07-27 10:09 ` [PATCH 4.9 21/33] usb: cdc_acm: Add quirk for Castles VEGA3000 Greg Kroah-Hartman
2018-07-27 10:09 ` [PATCH 4.9 22/33] usb: core: handle hub C_PORT_OVER_CURRENT condition Greg Kroah-Hartman
2018-07-27 10:09 ` [PATCH 4.9 23/33] usb: gadget: f_fs: Only return delayed status when len is 0 Greg Kroah-Hartman
2018-07-27 10:09 ` [PATCH 4.9 24/33] driver core: Partially revert "driver core: correct devices shutdown order" Greg Kroah-Hartman
2018-07-27 10:09 ` [PATCH 4.9 25/33] can: xilinx_can: fix RX loop if RXNEMP is asserted without RXOK Greg Kroah-Hartman
2018-07-27 10:09 ` [PATCH 4.9 26/33] can: xilinx_can: fix power management handling Greg Kroah-Hartman
2018-07-27 10:09 ` [PATCH 4.9 27/33] can: xilinx_can: fix recovery from error states not being propagated Greg Kroah-Hartman
2018-07-27 10:09 ` [PATCH 4.9 28/33] can: xilinx_can: fix device dropping off bus on RX overrun Greg Kroah-Hartman
2018-07-27 10:09 ` [PATCH 4.9 29/33] can: xilinx_can: keep only 1-2 frames in TX FIFO to fix TX accounting Greg Kroah-Hartman
2018-07-27 10:09 ` [PATCH 4.9 30/33] can: xilinx_can: fix incorrect clear of non-processed interrupts Greg Kroah-Hartman
2018-07-27 10:09 ` [PATCH 4.9 31/33] can: xilinx_can: fix RX overflow interrupt not being enabled Greg Kroah-Hartman
2018-07-27 10:09 ` [PATCH 4.9 32/33] turn off -Wattribute-alias Greg Kroah-Hartman
2018-07-27 10:09 ` [PATCH 4.9 33/33] exec: avoid gcc-8 warning for get_task_comm Greg Kroah-Hartman
2018-07-27 12:21 ` [PATCH 4.9 00/33] 4.9.116-stable review Nathan Chancellor
2018-07-27 17:29 ` Guenter Roeck
2018-07-27 20:01 ` Shuah Khan
2018-07-28 6:55 ` Naresh Kamboju
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=20180727100827.833022084@linuxfoundation.org \
--to=gregkh@linuxfoundation.org \
--cc=davem@davemloft.net \
--cc=linux-kernel@vger.kernel.org \
--cc=stable@vger.kernel.org \
--cc=syzbot+9adb4b567003cac781f0@syzkaller.appspotmail.com \
--cc=willemb@google.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).