linux/net
Taehee Yoo ba61539c6a ip_tunnel: fix use-after-free in ip_tunnel_lookup()
In the datapath, the ip_tunnel_lookup() is used and it internally uses
fallback tunnel device pointer, which is fb_tunnel_dev.
This pointer variable should be set to NULL when a fb interface is deleted.
But there is no routine to set fb_tunnel_dev pointer to NULL.
So, this pointer will be still used after interface is deleted and
it eventually results in the use-after-free problem.

Test commands:
    ip netns add A
    ip netns add B
    ip link add eth0 type veth peer name eth1
    ip link set eth0 netns A
    ip link set eth1 netns B

    ip netns exec A ip link set lo up
    ip netns exec A ip link set eth0 up
    ip netns exec A ip link add gre1 type gre local 10.0.0.1 \
	    remote 10.0.0.2
    ip netns exec A ip link set gre1 up
    ip netns exec A ip a a 10.0.100.1/24 dev gre1
    ip netns exec A ip a a 10.0.0.1/24 dev eth0

    ip netns exec B ip link set lo up
    ip netns exec B ip link set eth1 up
    ip netns exec B ip link add gre1 type gre local 10.0.0.2 \
	    remote 10.0.0.1
    ip netns exec B ip link set gre1 up
    ip netns exec B ip a a 10.0.100.2/24 dev gre1
    ip netns exec B ip a a 10.0.0.2/24 dev eth1
    ip netns exec A hping3 10.0.100.2 -2 --flood -d 60000 &
    ip netns del B

Splat looks like:
[   77.793450][    C3] ==================================================================
[   77.794702][    C3] BUG: KASAN: use-after-free in ip_tunnel_lookup+0xcc4/0xf30
[   77.795573][    C3] Read of size 4 at addr ffff888060bd9c84 by task hping3/2905
[   77.796398][    C3]
[   77.796664][    C3] CPU: 3 PID: 2905 Comm: hping3 Not tainted 5.8.0-rc1+ #616
[   77.797474][    C3] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   77.798453][    C3] Call Trace:
[   77.798815][    C3]  <IRQ>
[   77.799142][    C3]  dump_stack+0x9d/0xdb
[   77.799605][    C3]  print_address_description.constprop.7+0x2cc/0x450
[   77.800365][    C3]  ? ip_tunnel_lookup+0xcc4/0xf30
[   77.800908][    C3]  ? ip_tunnel_lookup+0xcc4/0xf30
[   77.801517][    C3]  ? ip_tunnel_lookup+0xcc4/0xf30
[   77.802145][    C3]  kasan_report+0x154/0x190
[   77.802821][    C3]  ? ip_tunnel_lookup+0xcc4/0xf30
[   77.803503][    C3]  ip_tunnel_lookup+0xcc4/0xf30
[   77.804165][    C3]  __ipgre_rcv+0x1ab/0xaa0 [ip_gre]
[   77.804862][    C3]  ? rcu_read_lock_sched_held+0xc0/0xc0
[   77.805621][    C3]  gre_rcv+0x304/0x1910 [ip_gre]
[   77.806293][    C3]  ? lock_acquire+0x1a9/0x870
[   77.806925][    C3]  ? gre_rcv+0xfe/0x354 [gre]
[   77.807559][    C3]  ? erspan_xmit+0x2e60/0x2e60 [ip_gre]
[   77.808305][    C3]  ? rcu_read_lock_sched_held+0xc0/0xc0
[   77.809032][    C3]  ? rcu_read_lock_held+0x90/0xa0
[   77.809713][    C3]  gre_rcv+0x1b8/0x354 [gre]
[ ... ]

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: c544193214 ("GRE: Refactor GRE tunneling code.")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-18 20:12:34 -07:00
..
6lowpan treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
9p 9p/xen: increase XEN_9PFS_RING_ORDER 2020-06-02 08:00:39 +02:00
802 net: 802: psnap.c: Use built-in RCU list checking 2020-02-24 13:02:53 -08:00
8021q Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-13 16:27:13 -07:00
appletalk ipv4,appletalk: move SIOCADDRT and SIOCDELRT handling into ->compat_ioctl 2020-05-18 17:35:02 -07:00
atm Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-13 16:27:13 -07:00
ax25 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-24 13:47:27 -07:00
batman-adv net: change addr_list_lock back to static key 2020-06-09 12:59:45 -07:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-06-03 16:27:18 -07:00
bpf bpf: Fix too large copy from user in bpf_test_init 2020-05-19 17:56:34 +02:00
bpfilter bpfilter: document build requirements for bpfilter_umh 2020-05-26 00:03:16 +09:00
bridge Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-13 16:27:13 -07:00
caif treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
can treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
ceph The highlights are: 2020-06-08 12:49:18 -07:00
core net: fix memleak in register_netdevice() 2020-06-18 20:05:54 -07:00
dcb treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
dccp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-13 16:27:13 -07:00
decnet treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
dns_resolver docs: networking: convert dns_resolver.txt to ReST 2020-04-28 14:39:46 -07:00
dsa Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-13 16:27:13 -07:00
ethernet net: move devres helpers into a separate source file 2020-05-23 16:56:17 -07:00
ethtool ethtool: linkinfo: remove an unnecessary NULL check 2020-06-05 13:10:02 -07:00
hsr treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
ieee802154 treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
ife net: Fix Kconfig indentation 2019-09-26 08:56:17 +02:00
ipv4 ip_tunnel: fix use-after-free in ip_tunnel_lookup() 2020-06-18 20:12:34 -07:00
ipv6 ip6_gre: fix use-after-free in ip6gre_tunnel_lookup() 2020-06-18 20:12:33 -07:00
iucv net/af_iucv: clean up function prototypes 2020-05-19 12:50:14 -07:00
kcm treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
key
l2tp treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
l3mdev treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
lapb treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
llc af_llc: fix if-statement empty body warning 2020-02-26 20:38:13 -08:00
mac80211 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-13 16:27:13 -07:00
mac802154 treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
mpls treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
mptcp mptcp: fix memory leak in mptcp_subflow_create_socket() 2020-06-15 18:08:50 -07:00
ncsi treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
netfilter netfilter: flowtable: Make nf_flow_table_offload_add/del_cb inline 2020-06-15 18:06:52 -07:00
netlabel treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
netlink Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-13 16:27:13 -07:00
netrom net: change addr_list_lock back to static key 2020-06-09 12:59:45 -07:00
nfc treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
nsh treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
openvswitch treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
packet treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
phonet sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
psample net: psample: fix build error when CONFIG_INET is not enabled 2020-05-23 16:36:05 -07:00
qrtr treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
rds net/rds: NULL pointer de-reference in rds_ib_add_one() 2020-06-15 12:58:59 -07:00
rfkill rfkill: Fix incorrect check to avoid NULL pointer dereference 2019-12-16 10:15:49 +01:00
rose net: change addr_list_lock back to static key 2020-06-09 12:59:45 -07:00
rxrpc rxrpc: Fix race between incoming ACK parser and retransmitter 2020-06-11 18:18:22 -07:00
sched net/sched: act_ct: Make tcf_ct_flow_table_restore_skb inline 2020-06-15 18:06:52 -07:00
sctp treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
smc treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
strparser
sunrpc NFS Client Updates for Linux 5.8 2020-06-11 12:22:41 -07:00
switchdev treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
tipc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-13 16:27:13 -07:00
tls treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
unix treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
vmw_vsock vsock/vmci: make vmci_vsock_transport_cb() static 2020-06-05 13:18:26 -07:00
wimax
wireless Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-13 16:27:13 -07:00
x25 treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
xdp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-13 16:27:13 -07:00
xfrm treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
Makefile net: move devres helpers into a separate source file 2020-05-23 16:56:17 -07:00
compat.c switch cmsghdr_from_user_compat_to_kern() to copy_from_user() 2020-06-01 12:05:45 -07:00
devres.c net: devres: provide devm_register_netdev() 2020-05-23 16:56:17 -07:00
socket.c net: remove kernel_setsockopt 2020-05-29 13:10:39 -07:00
sysctl_net.c