linux/net
Eric Dumazet 8ce48623f0 ipv6: tcp: restore IP6CB for pktoptions skbs
Baozeng Ding reported following KASAN splat :

BUG: KASAN: use-after-free in ip6_datagram_recv_specific_ctl+0x13f1/0x15c0 at addr ffff880029c84ec8
Read of size 1 by task poc/25548
Call Trace:
 [<ffffffff82cf43c9>] dump_stack+0x12e/0x185 /lib/dump_stack.c:15
 [<     inline     >] print_address_description /mm/kasan/report.c:204
 [<ffffffff817ced3b>] kasan_report_error+0x48b/0x4b0 /mm/kasan/report.c:283
 [<     inline     >] kasan_report /mm/kasan/report.c:303
 [<ffffffff817ced9e>] __asan_report_load1_noabort+0x3e/0x40 /mm/kasan/report.c:321
 [<ffffffff85c71da1>] ip6_datagram_recv_specific_ctl+0x13f1/0x15c0 /net/ipv6/datagram.c:687
 [<ffffffff85c734c3>] ip6_datagram_recv_ctl+0x33/0x40
 [<ffffffff85c0b07c>] do_ipv6_getsockopt.isra.4+0xaec/0x2150
 [<ffffffff85c0c7f6>] ipv6_getsockopt+0x116/0x230
 [<ffffffff859b5a12>] tcp_getsockopt+0x82/0xd0 /net/ipv4/tcp.c:3035
 [<ffffffff855fb385>] sock_common_getsockopt+0x95/0xd0 /net/core/sock.c:2647
 [<     inline     >] SYSC_getsockopt /net/socket.c:1776
 [<ffffffff855f8ba2>] SyS_getsockopt+0x142/0x230 /net/socket.c:1758
 [<ffffffff8685cdc5>] entry_SYSCALL_64_fastpath+0x23/0xc6
Memory state around the buggy address:
 ffff880029c84d80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff880029c84e00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> ffff880029c84e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff880029c84f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff880029c84f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

He also provided a syzkaller reproducer.

Issue is that ip6_datagram_recv_specific_ctl() expects to find IP6CB
data that was moved at a different place in tcp_v6_rcv()

This patch moves tcp_v6_restore_cb() up and calls it from
tcp_v6_do_rcv() when np->pktoptions is set.

Fixes: 971f10eca1 ("tcp: better TCP_SKB_CB layout to reduce cache line misses")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Baozeng Ding <sploving1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-13 11:07:34 -04:00
..
6lowpan 6lowpan: ndisc: no overreact if no short address is available 2016-09-19 20:19:34 +02:00
9p IB/core: add support to create a unsafe global rkey to ib_create_pd 2016-09-23 13:47:44 -04:00
802
8021q net: remove type_check from dev_get_nest_level() 2016-08-13 15:15:54 -07:00
appletalk appletalk: use IS_ENABLED() instead of checking for built-in or module 2016-09-10 21:19:10 -07:00
atm lec: use IS_ENABLED() instead of checking for built-in or module 2016-09-10 21:19:10 -07:00
ax25
batman-adv treewide: remove redundant #include <linux/kconfig.h> 2016-10-11 15:06:33 -07:00
bluetooth Bluetooth: Refactor append name and appearance 2016-10-06 11:52:29 +02:00
bridge netfilter: bridge: clarify bridge/netfilter message 2016-10-02 22:44:03 -04:00
caif
can
ceph crush: remove redundant local variable 2016-10-05 23:02:10 +02:00
core Merge branch 'akpm' (patches from Andrew) 2016-10-07 21:38:00 -07:00
dcb
dccp Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-07-29 17:38:46 -07:00
decnet
dns_resolver
dsa net: dsa: add port fast ageing 2016-09-23 08:38:50 -04:00
ethernet
hsr
ieee802154
ipv4 Merge branch 'akpm' (patches from Andrew) 2016-10-07 21:38:00 -07:00
ipv6 ipv6: tcp: restore IP6CB for pktoptions skbs 2016-10-13 11:07:34 -04:00
ipx
irda Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-09-23 06:46:57 -04:00
iucv Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-07-29 17:38:46 -07:00
kcm Merge branch 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-07 15:36:58 -07:00
key
l2tp l2tp: constify net_device_ops structures 2016-09-17 10:07:23 -04:00
l3mdev net: ipv6: Remove l3mdev_get_saddr6 2016-09-10 23:12:53 -07:00
lapb
llc llc: switch type to bool as the timeout is only tested versus 0 2016-09-17 10:05:05 -04:00
mac80211 Merge remote-tracking branch 'net-next/master' into mac80211-next 2016-10-04 09:46:44 +02:00
mac802154 mac802154: use rate limited warnings for malformed frames 2016-09-19 20:19:34 +02:00
mpls mpls: move mpls_hdr to a common location 2016-10-03 02:00:21 -04:00
ncsi net/ncsi: Introduce ncsi_stop_dev() 2016-10-04 02:11:51 -04:00
netfilter netfilter: Fix slab corruption. 2016-10-11 04:44:37 -04:00
netlabel
netlink netlink: do not enter direct reclaim from netlink_dump() 2016-10-06 20:53:13 -04:00
netrom
nfc
openvswitch openvswitch: add NETIF_F_HW_VLAN_STAG_TX to internal dev 2016-10-13 10:03:23 -04:00
packet packet: call fanout_release, while UNREGISTERING a netdev 2016-10-06 20:50:18 -04:00
phonet
qrtr
rds IB/core: add support to create a unsafe global rkey to ib_create_pd 2016-09-23 13:47:44 -04:00
rfkill
rose
rxrpc rxrpc: Don't request an ACK on the last DATA packet of a call's Tx phase 2016-10-06 08:11:51 +01:00
sched net_sched: reorder pernet ops and act ops registrations 2016-10-13 10:26:43 -04:00
sctp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-10-02 22:20:41 -04:00
strparser strparser: Propagate correct error code in strp_recv() 2016-10-12 01:51:49 -04:00
sunrpc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
switchdev switchdev: remove FIB offload infrastructure 2016-09-28 04:48:00 -04:00
tipc tipc: fix possible memory leak in tipc_udp_enable() 2016-09-13 11:28:32 -04:00
unix skb_splice_bits(): get rid of callback 2016-10-03 20:40:56 -04:00
vmw_vsock VSOCK: Don't dec ack backlog twice for rejected connections 2016-09-27 07:59:25 -04:00
wimax
wireless Merge remote-tracking branch 'net-next/master' into mac80211-next 2016-10-04 09:46:44 +02:00
x25 net: x25: remove null checks on arrays calling_ae and called_ae 2016-09-09 18:13:30 -07:00
xfrm proc: Reduce cache miss in xfrm_statistics_seq_show 2016-09-30 01:50:45 -04:00
Kconfig strparser: Stream parser for messages 2016-08-17 19:36:23 -04:00
Makefile strparser: Stream parser for messages 2016-08-17 19:36:23 -04:00
compat.c
socket.c vfs: Remove {get,set,remove}xattr inode operations 2016-10-07 21:48:36 -04:00
sysctl_net.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2016-10-06 09:52:23 -07:00