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
..
af_mpls.c	mpls: find_outdev: check for err ptr in addition to NULL check	2016-04-08 12:43:20 -04:00
internal.h	mpls: support for dead routes	2015-12-03 15:03:27 -05:00
Kconfig	mpls: ip tunnel support	2015-07-21 10:39:05 -07:00
Makefile	mpls: ip tunnel support	2015-07-21 10:39:05 -07:00
mpls_gso.c	net: Add priority to packet_offload objects.	2015-06-01 14:56:09 -07:00
mpls_iptunnel.c	mpls: autoload lwt module	2016-02-21 22:00:28 -05:00