linux/net/ipv6
Wei Wang 348a400272 ipv6: repair fib6 tree in failure case
In fib6_add(), it is possible that fib6_add_1() picks an intermediate
node and sets the node's fn->leaf to NULL in order to add this new
route. However, if fib6_add_rt2node() fails to add the new
route for some reason, fn->leaf will be left as NULL and could
potentially cause crash when fn->leaf is accessed in fib6_locate().
This patch makes sure fib6_repair_tree() is called to properly repair
fn->leaf in the above failure case.

Here is the syzkaller reported general protection fault in fib6_locate:
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Modules linked in:
CPU: 0 PID: 40937 Comm: syz-executor3 Not tainted
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d7d64100 ti: ffff8801d01a0000 task.ti: ffff8801d01a0000
RIP: 0010:[<ffffffff82a3e0e1>]  [<ffffffff82a3e0e1>] __ipv6_prefix_equal64_half include/net/ipv6.h:475 [inline]
RIP: 0010:[<ffffffff82a3e0e1>]  [<ffffffff82a3e0e1>] ipv6_prefix_equal include/net/ipv6.h:492 [inline]
RIP: 0010:[<ffffffff82a3e0e1>]  [<ffffffff82a3e0e1>] fib6_locate_1 net/ipv6/ip6_fib.c:1210 [inline]
RIP: 0010:[<ffffffff82a3e0e1>]  [<ffffffff82a3e0e1>] fib6_locate+0x281/0x3c0 net/ipv6/ip6_fib.c:1233
RSP: 0018:ffff8801d01a36a8  EFLAGS: 00010202
RAX: 0000000000000020 RBX: ffff8801bc790e00 RCX: ffffc90002983000
RDX: 0000000000001219 RSI: ffff8801d01a37a0 RDI: 0000000000000100
RBP: ffff8801d01a36f0 R08: 00000000000000ff R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000001
R13: dffffc0000000000 R14: ffff8801d01a37a0 R15: 0000000000000000
FS:  00007f6afd68c700(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004c6340 CR3: 00000000ba41f000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801d01a37a8 ffff8801d01a3780 ffffed003a0346f5 0000000c82a23ea0
 ffff8800b7bd7700 ffff8801d01a3780 ffff8800b6a1c940 ffffffff82a23ea0
 ffff8801d01a3920 ffff8801d01a3748 ffffffff82a223d6 ffff8801d7d64988
Call Trace:
 [<ffffffff82a223d6>] ip6_route_del+0x106/0x570 net/ipv6/route.c:2109
 [<ffffffff82a23f9d>] inet6_rtm_delroute+0xfd/0x100 net/ipv6/route.c:3075
 [<ffffffff82621359>] rtnetlink_rcv_msg+0x549/0x7a0 net/core/rtnetlink.c:3450
 [<ffffffff8274c1d1>] netlink_rcv_skb+0x141/0x370 net/netlink/af_netlink.c:2281
 [<ffffffff82613ddf>] rtnetlink_rcv+0x2f/0x40 net/core/rtnetlink.c:3456
 [<ffffffff8274ad38>] netlink_unicast_kernel net/netlink/af_netlink.c:1206 [inline]
 [<ffffffff8274ad38>] netlink_unicast+0x518/0x750 net/netlink/af_netlink.c:1232
 [<ffffffff8274b83e>] netlink_sendmsg+0x8ce/0xc30 net/netlink/af_netlink.c:1778
 [<ffffffff82564aff>] sock_sendmsg_nosec net/socket.c:609 [inline]
 [<ffffffff82564aff>] sock_sendmsg+0xcf/0x110 net/socket.c:619
 [<ffffffff82564d62>] sock_write_iter+0x222/0x3a0 net/socket.c:834
 [<ffffffff8178523d>] new_sync_write+0x1dd/0x2b0 fs/read_write.c:478
 [<ffffffff817853f4>] __vfs_write+0xe4/0x110 fs/read_write.c:491
 [<ffffffff81786c38>] vfs_write+0x178/0x4b0 fs/read_write.c:538
 [<ffffffff817892a9>] SYSC_write fs/read_write.c:585 [inline]
 [<ffffffff817892a9>] SyS_write+0xd9/0x1b0 fs/read_write.c:577
 [<ffffffff82c71e32>] entry_SYSCALL_64_fastpath+0x12/0x17

Note: there is no "Fixes" tag as this seems to be a bug introduced
very early.

Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-20 20:06:56 -07:00
..
ila Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-06-15 11:59:32 -04:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2017-06-30 06:27:09 -07:00
addrconf_core.c Ipvlan should return an error when an address is already in use. 2017-06-09 12:26:07 -04:00
addrconf.c net, ipv6: convert inet6_ifaddr.refcnt from atomic_t to refcount_t 2017-07-04 01:29:04 -07:00
addrlabel.c net, ipv6: convert ip6addrlbl_entry.refcnt from atomic_t to refcount_t 2017-07-04 01:29:04 -07:00
af_inet6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-04-26 22:39:08 -04:00
ah6.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2017-06-23 14:17:31 -04:00
anycast.c net, ipv6: convert ifacaddr6.aca_refcnt from atomic_t to refcount_t 2017-07-04 01:29:04 -07:00
calipso.c net, calipso: convert calipso_doi.refcount from atomic_t to refcount_t 2017-07-04 22:35:16 +01:00
datagram.c net: convert sock.sk_refcnt from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
esp6_offload.c esp6_offload: Fix IP6CB(skb)->nhoff for ESP GRO 2017-06-22 10:49:14 +02:00
esp6.c net: convert sock.sk_wmem_alloc from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
exthdrs_core.c
exthdrs_offload.c
exthdrs.c udp6: fix jumbogram reception 2017-07-31 22:01:21 -07:00
fib6_rules.c ipv6: Do not leak throw route references 2017-06-20 15:34:02 -04:00
fou6.c fou: make local function static 2017-05-21 13:42:36 -04:00
icmp.c net: don't global ICMP rate limit packets originating from loopback 2017-06-14 15:33:58 -04:00
inet6_connection_sock.c
inet6_hashtables.c net: convert sock.sk_refcnt from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
ip6_checksum.c
ip6_fib.c ipv6: repair fib6 tree in failure case 2017-08-20 20:06:56 -07:00
ip6_flowlabel.c
ip6_gre.c net: add netlink_ext_ack argument to rtnl_link_ops.validate 2017-06-26 23:13:22 -04:00
ip6_icmp.c
ip6_input.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-04-20 10:35:33 -04:00
ip6_offload.c ipv6: Fix leak in ipv6_gso_segment(). 2017-06-04 21:41:10 -04:00
ip6_offload.h
ip6_output.c udp: consistently apply ufo or fragmentation 2017-08-10 09:52:12 -07:00
ip6_tunnel.c net: add netlink_ext_ack argument to rtnl_link_ops.validate 2017-06-26 23:13:22 -04:00
ip6_udp_tunnel.c
ip6_vti.c net: add netlink_ext_ack argument to rtnl_link_ops.validate 2017-06-26 23:13:22 -04:00
ip6mr.c ip6mr: add netlink notifications on mrt6msg cache reports 2017-06-21 11:22:53 -04:00
ipcomp6.c
ipv6_sockglue.c Merge branch 'work.memdup_user' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-05 16:05:24 -07:00
Kconfig ipv6: sr: select DST_CACHE by default 2017-03-27 16:05:06 -07:00
Makefile
mcast_snoop.c
mcast.c net, ipv6: convert ifmcaddr6.mca_refcnt from atomic_t to refcount_t 2017-07-04 01:29:04 -07:00
mip6.c
ndisc.c networking: make skb_put & friends return void pointers 2017-06-16 11:48:39 -04:00
netfilter.c
output_core.c ipv6: avoid overflow of offset in ip6_find_1stfragopt 2017-07-19 22:50:14 -07:00
ping.c net: ping: do not abuse udp_poll() 2017-06-04 22:56:55 -04:00
proc.c proc: snmp6: Use correct type in memset 2017-06-12 09:53:14 -04:00
protocol.c net: Add sysctl to toggle early demux for tcp and udp 2017-03-24 13:17:07 -07:00
raw.c net: ping: do not abuse udp_poll() 2017-06-04 22:56:55 -04:00
reassembly.c
route.c ipv6: fix NULL dereference in ip6_route_dev_notify() 2017-08-15 17:06:34 -07:00
seg6_hmac.c
seg6_iptunnel.c net: add extack arg to lwtunnel build state 2017-05-30 11:55:32 -04:00
seg6.c ipv6: drop unused variables in seg6_genl_dumphac 2017-05-21 13:42:36 -04:00
sit.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-06-30 12:43:08 -04:00
syncookies.c ipv4: ipv6: initialize treq->txhash in cookie_v[46]_check() 2017-07-18 11:22:51 -07:00
sysctl_net_ipv6.c
tcp_ipv6.c tcp: fix possible deadlock in TCP stack vs BPF filter 2017-08-14 22:31:27 -07:00
tcpv6_offload.c
tunnel6.c
udp_impl.h udp: make *udp*_queue_rcv_skb() functions static 2017-05-18 10:23:33 -04:00
udp_offload.c net: avoid skb_warn_bad_offload false positives on UFO 2017-08-08 21:39:01 -07:00
udp.c datagram: When peeking datagrams with offset < 0 don't skip empty skbs 2017-08-18 15:12:54 -07:00
udplite.c
xfrm6_input.c xfrm6: Fix IPv6 payload_len in xfrm6_transport_finish 2017-06-22 10:49:14 +02:00
xfrm6_mode_beet.c networking: make skb_pull & friends return void pointers 2017-06-16 11:48:39 -04:00
xfrm6_mode_ro.c ipv6: xfrm: Handle errors reported by xfrm6_find_1stfragopt() 2017-06-02 13:57:27 -04:00
xfrm6_mode_transport.c ipv6: xfrm: Handle errors reported by xfrm6_find_1stfragopt() 2017-06-02 13:57:27 -04:00
xfrm6_mode_tunnel.c xfrm: Add encapsulation header offsets while SKB is not encrypted 2017-04-14 10:07:39 +02:00
xfrm6_output.c xfrm: Add an IPsec hardware offloading API 2017-04-14 10:06:10 +02:00
xfrm6_policy.c
xfrm6_protocol.c
xfrm6_state.c
xfrm6_tunnel.c net, ipv6: convert xfrm6_tunnel_spi.refcnt from atomic_t to refcount_t 2017-07-04 01:29:04 -07:00