linux/net
Eric W. Biederman 7c8a61d9ee net/sctp: Always set scope_id in sctp_inet6_skb_msgname
Alexandar Potapenko while testing the kernel with KMSAN and syzkaller
discovered that in some configurations sctp would leak 4 bytes of
kernel stack.

Working with his reproducer I discovered that those 4 bytes that
are leaked is the scope id of an ipv6 address returned by recvmsg.

With a little code inspection and a shrewd guess I discovered that
sctp_inet6_skb_msgname only initializes the scope_id field for link
local ipv6 addresses to the interface index the link local address
pertains to instead of initializing the scope_id field for all ipv6
addresses.

That is almost reasonable as scope_id's are meaniningful only for link
local addresses.  Set the scope_id in all other cases to 0 which is
not a valid interface index to make it clear there is nothing useful
in the scope_id field.

There should be no danger of breaking userspace as the stack leak
guaranteed that previously meaningless random data was being returned.

Fixes: 372f525b495c ("SCTP:  Resync with LKSCTP tree.")
History-tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Reported-by: Alexander Potapenko <glider@google.com>
Tested-by: Alexander Potapenko <glider@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-16 23:00:30 +09:00
..
6lowpan License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
9p License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
802 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
8021q Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-12 09:17:05 +09:00
appletalk License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
atm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
ax25 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
batman-adv
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
bpf
bridge net: bridge: add vlan_tunnel to bridge port policies 2017-11-14 21:54:55 +09:00
caif License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
can Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
ceph License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
core Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
dcb
dccp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
decnet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
dns_resolver
dsa net: dsa: lan9303: calculate offload_fwd_mark from tag 2017-11-14 21:47:48 +09:00
ethernet
hsr net: hsr: Convert timers to use timer_setup() 2017-10-25 13:00:27 +09:00
ieee802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
ife MAINTAINERS: Update Yotam's E-mail 2017-11-01 12:19:03 +09:00
ipv4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
ipv6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
ipx Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
iucv
kcm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
key af_key: replace BUG_ON on WARN_ON in net_exit hook 2017-11-14 15:45:52 +09:00
l2tp l2tp: exit_net cleanup check added 2017-11-14 15:45:53 +09:00
l3mdev
lapb
llc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
mac80211 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
mac802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
mpls Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
ncsi net/ncsi: Don't return error on normal response 2017-11-11 15:09:44 +09:00
netfilter netfilter: add ifdef around ctnetlink_proto_size 2017-11-16 10:49:00 +09:00
netlabel Merge branch 'linus' into locking/core, to resolve conflicts 2017-11-07 10:32:44 +01:00
netlink netlink: remove unnecessary forward declaration 2017-11-14 21:51:14 +09:00
netrom Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
nfc genetlink: fix genlmsg_nlhdr() 2017-11-16 10:49:00 +09:00
nsh openvswitch: enable NSH support 2017-11-08 16:12:33 +09:00
openvswitch openvswitch: meter: fix NULL pointer dereference in ovs_meter_cmd_reply_start 2017-11-15 14:16:07 +09:00
packet packet: exit_net cleanup check added 2017-11-14 15:45:52 +09:00
phonet phonet: exit_net cleanup check added 2017-11-14 15:45:53 +09:00
psample MAINTAINERS: Update Yotam's E-mail 2017-11-01 12:19:03 +09:00
qrtr Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-10 10:00:18 +09:00
rds Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-12 09:17:05 +09:00
rfkill
rose net: rose: mark expected switch fall-throughs 2017-10-22 02:02:26 +01:00
rxrpc RxRPC development 2017-11-14 16:17:38 +09:00
sched netem: remove unnecessary 64 bit modulus 2017-11-15 14:14:16 +09:00
sctp net/sctp: Always set scope_id in sctp_inet6_skb_msgname 2017-11-16 23:00:30 +09:00
smc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
strparser strparser: Use delayed work instead of timer for msg timeout 2017-10-25 10:37:11 +09:00
sunrpc Modules updates for v4.15 2017-11-15 13:46:33 -08:00
switchdev net: bridge: Add/del switchdev object on host join/leave 2017-11-10 13:41:40 +09:00
tipc tipc: enforce valid ratio between skb truesize and contents 2017-11-16 10:49:00 +09:00
tls tls: don't override sk_write_space if tls_set_sw_offload fails. 2017-11-14 16:26:35 +09:00
unix Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
vmw_vsock Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
wimax License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
wireless genetlink: fix genlmsg_nlhdr() 2017-11-16 10:49:00 +09:00
x25 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
xfrm Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec 2017-11-16 22:33:54 +09:00
compat.c
Kconfig
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
socket.c
sysctl_net.c