linux/net
Vlad Yasevich b14878ccb7 net: sctp: cache auth_enable per endpoint
Currently, it is possible to create an SCTP socket, then switch
auth_enable via sysctl setting to 1 and crash the system on connect:

Oops[#1]:
CPU: 0 PID: 0 Comm: swapper Not tainted 3.14.1-mipsgit-20140415 #1
task: ffffffff8056ce80 ti: ffffffff8055c000 task.ti: ffffffff8055c000
[...]
Call Trace:
[<ffffffff8043c4e8>] sctp_auth_asoc_set_default_hmac+0x68/0x80
[<ffffffff8042b300>] sctp_process_init+0x5e0/0x8a4
[<ffffffff8042188c>] sctp_sf_do_5_1B_init+0x234/0x34c
[<ffffffff804228c8>] sctp_do_sm+0xb4/0x1e8
[<ffffffff80425a08>] sctp_endpoint_bh_rcv+0x1c4/0x214
[<ffffffff8043af68>] sctp_rcv+0x588/0x630
[<ffffffff8043e8e8>] sctp6_rcv+0x10/0x24
[<ffffffff803acb50>] ip6_input+0x2c0/0x440
[<ffffffff8030fc00>] __netif_receive_skb_core+0x4a8/0x564
[<ffffffff80310650>] process_backlog+0xb4/0x18c
[<ffffffff80313cbc>] net_rx_action+0x12c/0x210
[<ffffffff80034254>] __do_softirq+0x17c/0x2ac
[<ffffffff800345e0>] irq_exit+0x54/0xb0
[<ffffffff800075a4>] ret_from_irq+0x0/0x4
[<ffffffff800090ec>] rm7k_wait_irqoff+0x24/0x48
[<ffffffff8005e388>] cpu_startup_entry+0xc0/0x148
[<ffffffff805a88b0>] start_kernel+0x37c/0x398
Code: dd0900b8  000330f8  0126302d <dcc60000> 50c0fff1  0047182a  a48306a0
03e00008  00000000
---[ end trace b530b0551467f2fd ]---
Kernel panic - not syncing: Fatal exception in interrupt

What happens while auth_enable=0 in that case is, that
ep->auth_hmacs is initialized to NULL in sctp_auth_init_hmacs()
when endpoint is being created.

After that point, if an admin switches over to auth_enable=1,
the machine can crash due to NULL pointer dereference during
reception of an INIT chunk. When we enter sctp_process_init()
via sctp_sf_do_5_1B_init() in order to respond to an INIT chunk,
the INIT verification succeeds and while we walk and process
all INIT params via sctp_process_param() we find that
net->sctp.auth_enable is set, therefore do not fall through,
but invoke sctp_auth_asoc_set_default_hmac() instead, and thus,
dereference what we have set to NULL during endpoint
initialization phase.

The fix is to make auth_enable immutable by caching its value
during endpoint initialization, so that its original value is
being carried along until destruction. The bug seems to originate
from the very first days.

Fix in joint work with Daniel Borkmann.

Reported-by: Joshua Kinard <kumba@gentoo.org>
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Tested-by: Joshua Kinard <kumba@gentoo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-18 18:32:00 -04:00
..
9p A bunch of updates and cleanup within the transport layer, 2014-04-11 14:14:57 -07:00
802 neigh: use NEIGH_VAR_INIT in ndo_neigh_setup functions. 2014-01-16 11:31:58 -08:00
8021q vlan: Fix lockdep warning when vlan dev handle notification 2014-04-18 17:48:30 -04:00
appletalk appletalk: fix checkpatch error with indent 2014-02-14 16:18:32 -05:00
atm net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
ax25 net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
batman-adv batman-adv: Start new development cycle 2014-03-22 09:18:59 +01:00
bluetooth net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
bridge bridge: Fix double free and memory leak around br_allowed_ingress 2014-04-11 15:12:47 -04:00
caif net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
can can: remove CAN FD compatibility for CAN 2.0 sockets 2014-03-03 14:29:52 +01:00
ceph net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
core vlan: Fix lockdep warning when vlan dev handle notification 2014-04-18 17:48:30 -04:00
dcb dcb: use __dev_get_by_name instead of dev_get_by_name to find interface 2014-01-14 18:50:46 -08:00
dccp ipv4: add a sock pointer to ip_queue_xmit() 2014-04-15 12:58:34 -04:00
decnet ipv4: add a sock pointer to dst->output() path. 2014-04-15 13:47:15 -04:00
dns_resolver net/*: Fix FSF address in file headers 2013-12-06 12:37:57 -05:00
dsa dsa: Use ether_addr_copy 2014-01-21 18:13:05 -08:00
ethernet net: eth_type_trans() should use skb_header_pointer() 2014-01-16 15:30:31 -08:00
hsr hsr: replace del_timer by del_timer_sync 2014-03-27 15:28:06 -04:00
ieee802154 mac802154: make csma/cca parameters per-wpan 2014-04-01 16:25:51 -04:00
ipv4 ip_tunnel: use the right netns in ioctl handler 2014-04-16 15:16:02 -04:00
ipv6 ip6_tunnel: use the right netns in ioctl handler 2014-04-16 15:16:02 -04:00
ipx ipx: implement shutdown() 2014-02-12 19:26:32 -05:00
irda net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
iucv net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
key net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
l2tp ipv4: add a sock pointer to ip_queue_xmit() 2014-04-15 12:58:34 -04:00
lapb
llc llc: remove noisy WARN from llc_mac_hdr_init 2014-01-28 18:01:32 -08:00
mac80211 mac80211: exclude AP_VLAN interfaces from tx power calculation 2014-04-11 09:37:41 +02:00
mac802154 mac802154: fix duplicate #include headers 2014-04-07 13:18:44 -04:00
mpls
netfilter netfilter: nf_tables: fix nft_cmp_fast failure on big endian for size < 4 2014-04-14 10:38:02 +02:00
netlabel netlabel: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
netlink net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
netrom net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
nfc net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
openvswitch ipv4: add a sock pointer to dst->output() path. 2014-04-15 13:47:15 -04:00
packet net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
phonet net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
rds net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
rfkill net: rfkill: move poll work to power efficient workqueue 2014-02-04 21:58:16 +01:00
rose net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
rxrpc net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
sched net-sysfs: expose number of carrier on/off changes 2014-03-31 16:24:52 -04:00
sctp net: sctp: cache auth_enable per endpoint 2014-04-18 18:32:00 -04:00
sunrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-04-12 17:31:22 -07:00
tipc net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
unix net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
vmw_vsock net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
wimax wimax: remove dead code 2013-11-21 13:09:42 -05:00
wireless Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem 2014-03-21 14:02:04 -04:00
x25 net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
xfrm ipv4: add a sock pointer to dst->output() path. 2014-04-15 13:47:15 -04:00
compat.c net/compat: convert to COMPAT_SYSCALL_DEFINE with changing parameter types 2014-03-06 16:30:45 +01:00
Kconfig Merge branch 'for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2014-04-03 13:05:42 -07:00
Makefile net: move 6lowpan compression code to separate module 2014-01-15 15:36:38 -08:00
nonet.c
socket.c net: use SYSCALL_DEFINEx for sys_recv 2014-04-16 15:15:05 -04:00
sysctl_net.c