| From foo@baz Mon 27 Jan 2020 04:06:27 PM CET |
| From: Eric Dumazet <edumazet@google.com> |
| Date: Tue, 21 Jan 2020 23:17:14 -0800 |
| Subject: gtp: make sure only SOCK_DGRAM UDP sockets are accepted |
| |
| From: Eric Dumazet <edumazet@google.com> |
| |
| [ Upstream commit 940ba14986657a50c15f694efca1beba31fa568f ] |
| |
| A malicious user could use RAW sockets and fool |
| GTP using them as standard SOCK_DGRAM UDP sockets. |
| |
| BUG: KMSAN: uninit-value in udp_tunnel_encap_enable include/net/udp_tunnel.h:174 [inline] |
| BUG: KMSAN: uninit-value in setup_udp_tunnel_sock+0x45e/0x6f0 net/ipv4/udp_tunnel.c:85 |
| CPU: 0 PID: 11262 Comm: syz-executor613 Not tainted 5.5.0-rc5-syzkaller #0 |
| Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 |
| Call Trace: |
| __dump_stack lib/dump_stack.c:77 [inline] |
| dump_stack+0x1c9/0x220 lib/dump_stack.c:118 |
| kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118 |
| __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 |
| udp_tunnel_encap_enable include/net/udp_tunnel.h:174 [inline] |
| setup_udp_tunnel_sock+0x45e/0x6f0 net/ipv4/udp_tunnel.c:85 |
| gtp_encap_enable_socket+0x37f/0x5a0 drivers/net/gtp.c:827 |
| gtp_encap_enable drivers/net/gtp.c:844 [inline] |
| gtp_newlink+0xfb/0x1e50 drivers/net/gtp.c:666 |
| __rtnl_newlink net/core/rtnetlink.c:3305 [inline] |
| rtnl_newlink+0x2973/0x3920 net/core/rtnetlink.c:3363 |
| rtnetlink_rcv_msg+0x1153/0x1570 net/core/rtnetlink.c:5424 |
| netlink_rcv_skb+0x451/0x650 net/netlink/af_netlink.c:2477 |
| rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5442 |
| netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] |
| netlink_unicast+0xf9e/0x1100 net/netlink/af_netlink.c:1328 |
| netlink_sendmsg+0x1248/0x14d0 net/netlink/af_netlink.c:1917 |
| sock_sendmsg_nosec net/socket.c:639 [inline] |
| sock_sendmsg net/socket.c:659 [inline] |
| ____sys_sendmsg+0x12b6/0x1350 net/socket.c:2330 |
| ___sys_sendmsg net/socket.c:2384 [inline] |
| __sys_sendmsg+0x451/0x5f0 net/socket.c:2417 |
| __do_sys_sendmsg net/socket.c:2426 [inline] |
| __se_sys_sendmsg+0x97/0xb0 net/socket.c:2424 |
| __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2424 |
| do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296 |
| entry_SYSCALL_64_after_hwframe+0x44/0xa9 |
| RIP: 0033:0x441359 |
| Code: e8 ac e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 |
| RSP: 002b:00007fff1cd0ac28 EFLAGS: 00000246 ORIG_RAX: 000000000000002e |
| RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441359 |
| RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000003 |
| RBP: 00000000006cb018 R08: 00000000004002c8 R09: 00000000004002c8 |
| R10: 00000000004002c8 R11: 0000000000000246 R12: 00000000004020d0 |
| R13: 0000000000402160 R14: 0000000000000000 R15: 0000000000000000 |
| |
| Uninit was created at: |
| kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:144 |
| kmsan_internal_alloc_meta_for_pages mm/kmsan/kmsan_shadow.c:307 [inline] |
| kmsan_alloc_page+0x12a/0x310 mm/kmsan/kmsan_shadow.c:336 |
| __alloc_pages_nodemask+0x57f2/0x5f60 mm/page_alloc.c:4800 |
| alloc_pages_current+0x67d/0x990 mm/mempolicy.c:2207 |
| alloc_pages include/linux/gfp.h:534 [inline] |
| alloc_slab_page+0x111/0x12f0 mm/slub.c:1511 |
| allocate_slab mm/slub.c:1656 [inline] |
| new_slab+0x2bc/0x1130 mm/slub.c:1722 |
| new_slab_objects mm/slub.c:2473 [inline] |
| ___slab_alloc+0x1533/0x1f30 mm/slub.c:2624 |
| __slab_alloc mm/slub.c:2664 [inline] |
| slab_alloc_node mm/slub.c:2738 [inline] |
| slab_alloc mm/slub.c:2783 [inline] |
| kmem_cache_alloc+0xb23/0xd70 mm/slub.c:2788 |
| sk_prot_alloc+0xf2/0x620 net/core/sock.c:1597 |
| sk_alloc+0xf0/0xbe0 net/core/sock.c:1657 |
| inet_create+0x7c7/0x1370 net/ipv4/af_inet.c:321 |
| __sock_create+0x8eb/0xf00 net/socket.c:1420 |
| sock_create net/socket.c:1471 [inline] |
| __sys_socket+0x1a1/0x600 net/socket.c:1513 |
| __do_sys_socket net/socket.c:1522 [inline] |
| __se_sys_socket+0x8d/0xb0 net/socket.c:1520 |
| __x64_sys_socket+0x4a/0x70 net/socket.c:1520 |
| do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296 |
| entry_SYSCALL_64_after_hwframe+0x44/0xa9 |
| |
| Fixes: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)") |
| Signed-off-by: Eric Dumazet <edumazet@google.com> |
| Cc: Pablo Neira <pablo@netfilter.org> |
| Reported-by: syzbot <syzkaller@googlegroups.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/net/gtp.c | 4 +++- |
| 1 file changed, 3 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/net/gtp.c |
| +++ b/drivers/net/gtp.c |
| @@ -836,7 +836,9 @@ static int gtp_encap_enable(struct net_d |
| return -ENOENT; |
| } |
| |
| - if (sock0->sk->sk_protocol != IPPROTO_UDP) { |
| + if (sock0->sk->sk_protocol != IPPROTO_UDP || |
| + sock0->sk->sk_type != SOCK_DGRAM || |
| + (sock0->sk->sk_family != AF_INET && sock0->sk->sk_family != AF_INET6)) { |
| netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp0); |
| err = -EINVAL; |
| goto err1; |
