linux/net
Roopa Prabhu 94a57f1f8a mpls: find_outdev: check for err ptr in addition to NULL check
find_outdev calls inet{,6}_fib_lookup_dev() or dev_get_by_index() to
find the output device. In case of an error, inet{,6}_fib_lookup_dev()
returns error pointer and dev_get_by_index() returns NULL. But the function
only checks for NULL and thus can end up calling dev_put on an ERR_PTR.
This patch adds an additional check for err ptr after the NULL check.

Before: Trying to add an mpls route with no oif from user, no available
path to 10.1.1.8 and no default route:
$ip -f mpls route add 100 as 200 via inet 10.1.1.8
[  822.337195] BUG: unable to handle kernel NULL pointer dereference at
00000000000003a3
[  822.340033] IP: [<ffffffff8148781e>] mpls_nh_assign_dev+0x10b/0x182
[  822.340033] PGD 1db38067 PUD 1de9e067 PMD 0
[  822.340033] Oops: 0000 [#1] SMP
[  822.340033] Modules linked in:
[  822.340033] CPU: 0 PID: 11148 Comm: ip Not tainted 4.5.0-rc7+ #54
[  822.340033] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org
04/01/2014
[  822.340033] task: ffff88001db82580 ti: ffff88001dad4000 task.ti:
ffff88001dad4000
[  822.340033] RIP: 0010:[<ffffffff8148781e>]  [<ffffffff8148781e>]
mpls_nh_assign_dev+0x10b/0x182
[  822.340033] RSP: 0018:ffff88001dad7a88  EFLAGS: 00010282
[  822.340033] RAX: ffffffffffffff9b RBX: ffffffffffffff9b RCX:
0000000000000002
[  822.340033] RDX: 00000000ffffff9b RSI: 0000000000000008 RDI:
0000000000000000
[  822.340033] RBP: ffff88001ddc9ea0 R08: ffff88001e9f1768 R09:
0000000000000000
[  822.340033] R10: ffff88001d9c1100 R11: ffff88001e3c89f0 R12:
ffffffff8187e0c0
[  822.340033] R13: ffffffff8187e0c0 R14: ffff88001ddc9e80 R15:
0000000000000004
[  822.340033] FS:  00007ff9ed798700(0000) GS:ffff88001fc00000(0000)
knlGS:0000000000000000
[  822.340033] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  822.340033] CR2: 00000000000003a3 CR3: 000000001de89000 CR4:
00000000000006f0
[  822.340033] Stack:
[  822.340033]  0000000000000000 0000000100000000 0000000000000000
0000000000000000
[  822.340033]  0000000000000000 0801010a00000000 0000000000000000
0000000000000000
[  822.340033]  0000000000000004 ffffffff8148749b ffffffff8187e0c0
000000000000001c
[  822.340033] Call Trace:
[  822.340033]  [<ffffffff8148749b>] ? mpls_rt_alloc+0x2b/0x3e
[  822.340033]  [<ffffffff81488e66>] ? mpls_rtm_newroute+0x358/0x3e2
[  822.340033]  [<ffffffff810e7bbc>] ? get_page+0x5/0xa
[  822.340033]  [<ffffffff813b7d94>] ? rtnetlink_rcv_msg+0x17e/0x191
[  822.340033]  [<ffffffff8111794e>] ? __kmalloc_track_caller+0x8c/0x9e
[  822.340033]  [<ffffffff813c9393>] ?
rht_key_hashfn.isra.20.constprop.57+0x14/0x1f
[  822.340033]  [<ffffffff813b7c16>] ? __rtnl_unlock+0xc/0xc
[  822.340033]  [<ffffffff813cb794>] ? netlink_rcv_skb+0x36/0x82
[  822.340033]  [<ffffffff813b4507>] ? rtnetlink_rcv+0x1f/0x28
[  822.340033]  [<ffffffff813cb2b1>] ? netlink_unicast+0x106/0x189
[  822.340033]  [<ffffffff813cb5b3>] ? netlink_sendmsg+0x27f/0x2c8
[  822.340033]  [<ffffffff81392ede>] ? sock_sendmsg_nosec+0x10/0x1b
[  822.340033]  [<ffffffff81393df1>] ? ___sys_sendmsg+0x182/0x1e3
[  822.340033]  [<ffffffff810e4f35>] ?
__alloc_pages_nodemask+0x11c/0x1e4
[  822.340033]  [<ffffffff8110619c>] ? PageAnon+0x5/0xd
[  822.340033]  [<ffffffff811062fe>] ? __page_set_anon_rmap+0x45/0x52
[  822.340033]  [<ffffffff810e7bbc>] ? get_page+0x5/0xa
[  822.340033]  [<ffffffff810e85ab>] ? __lru_cache_add+0x1a/0x3a
[  822.340033]  [<ffffffff81087ea9>] ? current_kernel_time64+0x9/0x30
[  822.340033]  [<ffffffff813940c4>] ? __sys_sendmsg+0x3c/0x5a
[  822.340033]  [<ffffffff8148f597>] ?
entry_SYSCALL_64_fastpath+0x12/0x6a
[  822.340033] Code: 83 08 04 00 00 65 ff 00 48 8b 3c 24 e8 40 7c f2 ff
eb 13 48 c7 c3 9f ff ff ff eb 0f 89 ce e8 f1 ae f1 ff 48 89 c3 48 85 db
74 15 <48> 8b 83 08 04 00 00 65 ff 08 48 81 fb 00 f0 ff ff 76 0d eb 07
[  822.340033] RIP  [<ffffffff8148781e>] mpls_nh_assign_dev+0x10b/0x182
[  822.340033]  RSP <ffff88001dad7a88>
[  822.340033] CR2: 00000000000003a3
[  822.435363] ---[ end trace 98cc65e6f6b8bf11 ]---

After patch:
$ip -f mpls route add 100 as 200 via inet 10.1.1.8
RTNETLINK answers: Network is unreachable

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-08 12:43:20 -04:00
..
6lowpan 6lowpan: iphc: fix SAM/DAM bit comment 2016-03-10 19:51:29 +01:00
9p net/9p: convert to new CQ API 2016-03-10 20:54:09 -05:00
802
8021q vlan: propagate gso_max_segs 2016-03-17 21:05:01 -04:00
appletalk
atm
ax25 ax25: add link layer header validation function 2016-03-09 22:13:01 -05:00
batman-adv batman-adv: clarify CFG80211 dependency 2016-03-02 13:45:47 -05:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2016-03-19 10:05:34 -07:00
bridge Revert "bridge: Fix incorrect variable assignment on error path in br_sysfs_addbr" 2016-04-06 15:42:45 -04:00
caif net: caif: fix misleading indentation 2016-03-14 13:09:50 -04:00
can
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2016-03-26 15:53:16 -07:00
core GRE: Disable segmentation offloads w/ CSUM and we are encapsulated via FOU 2016-04-07 16:56:33 -04:00
dcb
dccp tcp/dccp: remove obsolete WARN_ON() in icmp handlers 2016-03-17 21:06:40 -04:00
decnet
dns_resolver
dsa net: dsa: refine netdev event notifier 2016-03-14 16:05:32 -04:00
ethernet eth: Pull header from first fragment via eth_get_headlen 2016-02-24 13:58:05 -05:00
hsr
ieee802154 ieee802154: 6lowpan: fix return of netdev notifier 2016-02-23 20:29:40 +01:00
ipv4 GRE: Disable segmentation offloads w/ CSUM and we are encapsulated via FOU 2016-04-07 16:56:33 -04:00
ipv6 ipv6: Count in extension headers in skb->network_header 2016-04-07 22:41:37 -04:00
ipx
irda
iucv
kcm kcm: Add receive message timeout 2016-03-09 16:36:15 -05:00
key
l2tp ipv6: l2tp: fix a potential issue in l2tp_ip6_recv 2016-04-04 16:00:28 -04:00
l3mdev net: l3mdev: address selection should only consider devices in L3 domain 2016-02-26 14:22:26 -05:00
lapb
llc
mac80211 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-03-08 12:34:12 -05:00
mac802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2016-03-19 10:05:34 -07:00
mpls mpls: find_outdev: check for err ptr in addition to NULL check 2016-04-08 12:43:20 -04:00
netfilter netfilter: nfnetlink_queue: honor NFQA_CFG_F_FAIL_OPEN when netlink unicast fails 2016-03-28 17:59:20 +02:00
netlabel netlabel: do not initialise statics to NULL 2016-03-07 11:08:26 -05:00
netlink netlink: add support for NIC driver ioctls 2016-03-22 15:45:44 -04:00
netrom
nfc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2016-03-19 10:05:34 -07:00
openvswitch Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2016-03-28 15:38:59 -04:00
packet af_packet: tone down the Tx-ring unsupported spew. 2016-04-06 16:05:20 -04:00
phonet
rds RDS: fix congestion map corruption for PAGE_SIZE > 4k 2016-04-07 16:58:28 -04:00
rfkill Here's another round of updates for -next: 2016-03-01 17:03:27 -05:00
rose
rxrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2016-03-19 10:05:34 -07:00
sched cls_bpf: reset class and reuse major in da 2016-03-18 19:35:21 -04:00
sctp sctp: flush if we can't fit another DATA chunk 2016-04-05 15:39:44 -04:00
sunrpc Various bugfixes, a RDMA update from Chuck Lever, and support for a new 2016-03-24 10:41:00 -07:00
switchdev switchdev: fix typo in comments/doc 2016-03-24 14:51:24 -04:00
tipc tipc: make sure IPv6 header fits in skb headroom 2016-03-14 12:23:12 -04:00
unix Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-02-23 00:09:14 -05:00
vmw_vsock VSOCK: Detach QP check should filter out non matching QPs. 2016-04-06 16:39:09 -04:00
wimax
wireless Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2016-03-19 10:05:34 -07:00
x25
xfrm xfrm: Fix crash observed during device unregistration and decryption 2016-03-24 14:29:36 -04:00
compat.c
Kconfig Make DST_CACHE a silent config option 2016-03-21 22:56:38 -04:00
Makefile kcm: Kernel Connection Multiplexor module 2016-03-09 16:36:14 -05:00
socket.c net: Fix use after free in the recvmmsg exit path 2016-03-14 12:41:49 -04:00
sysctl_net.c