linux/net/ipv6
Eric Dumazet 0e23387491 ipv6: fix races in ip6_dst_destroy()
We had many syzbot reports that seem to be caused by use-after-free
of struct fib6_info.

ip6_dst_destroy(), fib6_drop_pcpu_from() and rt6_remove_exception()
are writers vs rt->from, and use non consistent synchronization among
themselves.

Switching to xchg() will solve the issues with no possible
lockdep issues.

BUG: KASAN: user-memory-access in atomic_dec_and_test include/asm-generic/atomic-instrumented.h:747 [inline]
BUG: KASAN: user-memory-access in fib6_info_release include/net/ip6_fib.h:294 [inline]
BUG: KASAN: user-memory-access in fib6_info_release include/net/ip6_fib.h:292 [inline]
BUG: KASAN: user-memory-access in fib6_drop_pcpu_from net/ipv6/ip6_fib.c:927 [inline]
BUG: KASAN: user-memory-access in fib6_purge_rt+0x4f6/0x670 net/ipv6/ip6_fib.c:960
Write of size 4 at addr 0000000000ffffb4 by task syz-executor.1/7649

CPU: 0 PID: 7649 Comm: syz-executor.1 Not tainted 5.1.0-rc6+ #183
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+0x172/0x1f0 lib/dump_stack.c:113
 kasan_report.cold+0x5/0x40 mm/kasan/report.c:321
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x123/0x190 mm/kasan/generic.c:191
 kasan_check_write+0x14/0x20 mm/kasan/common.c:108
 atomic_dec_and_test include/asm-generic/atomic-instrumented.h:747 [inline]
 fib6_info_release include/net/ip6_fib.h:294 [inline]
 fib6_info_release include/net/ip6_fib.h:292 [inline]
 fib6_drop_pcpu_from net/ipv6/ip6_fib.c:927 [inline]
 fib6_purge_rt+0x4f6/0x670 net/ipv6/ip6_fib.c:960
 fib6_del_route net/ipv6/ip6_fib.c:1813 [inline]
 fib6_del+0xac2/0x10a0 net/ipv6/ip6_fib.c:1844
 fib6_clean_node+0x3a8/0x590 net/ipv6/ip6_fib.c:2006
 fib6_walk_continue+0x495/0x900 net/ipv6/ip6_fib.c:1928
 fib6_walk+0x9d/0x100 net/ipv6/ip6_fib.c:1976
 fib6_clean_tree+0xe0/0x120 net/ipv6/ip6_fib.c:2055
 __fib6_clean_all+0x118/0x2a0 net/ipv6/ip6_fib.c:2071
 fib6_clean_all+0x2b/0x40 net/ipv6/ip6_fib.c:2082
 rt6_sync_down_dev+0x134/0x150 net/ipv6/route.c:4057
 rt6_disable_ip+0x27/0x5f0 net/ipv6/route.c:4062
 addrconf_ifdown+0xa2/0x1220 net/ipv6/addrconf.c:3705
 addrconf_notify+0x19a/0x2260 net/ipv6/addrconf.c:3630
 notifier_call_chain+0xc7/0x240 kernel/notifier.c:93
 __raw_notifier_call_chain kernel/notifier.c:394 [inline]
 raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:401
 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1753
 call_netdevice_notifiers_extack net/core/dev.c:1765 [inline]
 call_netdevice_notifiers net/core/dev.c:1779 [inline]
 dev_close_many+0x33f/0x6f0 net/core/dev.c:1522
 rollback_registered_many+0x43b/0xfd0 net/core/dev.c:8177
 rollback_registered+0x109/0x1d0 net/core/dev.c:8242
 unregister_netdevice_queue net/core/dev.c:9289 [inline]
 unregister_netdevice_queue+0x1ee/0x2c0 net/core/dev.c:9282
 unregister_netdevice include/linux/netdevice.h:2658 [inline]
 __tun_detach+0xd5b/0x1000 drivers/net/tun.c:727
 tun_detach drivers/net/tun.c:744 [inline]
 tun_chr_close+0xe0/0x180 drivers/net/tun.c:3443
 __fput+0x2e5/0x8d0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x14a/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x90a/0x2fa0 kernel/exit.c:876
 do_group_exit+0x135/0x370 kernel/exit.c:980
 __do_sys_exit_group kernel/exit.c:991 [inline]
 __se_sys_exit_group kernel/exit.c:989 [inline]
 __x64_sys_exit_group+0x44/0x50 kernel/exit.c:989
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458da9
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffeafc2a6a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000001c RCX: 0000000000458da9
RDX: 0000000000412a80 RSI: 0000000000a54ef0 RDI: 0000000000000043
RBP: 00000000004be552 R08: 000000000000000c R09: 000000000004c0d1
R10: 0000000002341940 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00007ffeafc2a7f0 R14: 000000000004c065 R15: 00007ffeafc2a800

Fixes: a68886a691 ("net/ipv6: Make from in rt6_info rcu protected")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: David Ahern <dsahern@gmail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-30 23:38:38 -04:00
..
ila ila: Fix rhashtable walker list corruption 2019-03-27 22:46:16 -07:00
netfilter netfilter: ip6t_srh: fix NULL pointer dereferences 2019-03-18 16:22:48 +01:00
addrconf_core.c ipv6_stub: add ipv6_route_input stub/proxy. 2019-02-13 18:27:55 -08:00
addrconf.c net: ignore sysctl_devconf_inherit_init_net without SYSCTL 2019-03-04 13:14:34 -08:00
addrlabel.c net: ipv6: addrlabel: fix spelling mistake "requewst" -> "request" 2019-04-18 10:44:17 -07:00
af_inet6.c ipv6_stub: add ipv6_route_input stub/proxy. 2019-02-13 18:27:55 -08:00
ah6.c
anycast.c net/ipv6: compute anycast address hash only if dev is null 2018-11-08 17:04:43 -08:00
calipso.c
datagram.c ipv6: fix kernel-infoleak in ipv6_local_error() 2019-01-10 09:36:41 -05:00
esp6_offload.c xfrm: Reset secpath in xfrm failure 2019-03-08 07:32:16 +01:00
esp6.c esp: Skip TX bytes accounting when sending from a request socket 2019-01-28 11:20:58 +01:00
exthdrs_core.c
exthdrs_offload.c
exthdrs.c
fib6_notifier.c
fib6_rules.c
fou6.c fou, fou6: avoid uninit-value in gue_err() and gue6_err() 2019-03-08 15:19:53 -08:00
icmp.c ipv6: icmp: use percpu allocation 2019-02-24 21:57:26 -08:00
inet6_connection_sock.c
inet6_hashtables.c net: tcp6: prefer listeners bound to an address 2018-12-14 15:55:20 -08:00
ip6_checksum.c net: udp: fix handling of CHECKSUM_COMPLETE packets 2018-10-24 14:18:16 -07:00
ip6_fib.c ipv6: fix races in ip6_dst_destroy() 2019-04-30 23:38:38 -04:00
ip6_flowlabel.c ipv6/flowlabel: wait rcu grace period before put_pid() 2019-04-29 23:30:13 -04:00
ip6_gre.c net: ip6_gre: fix possible use-after-free in ip6erspan_rcv 2019-04-08 16:16:47 -07:00
ip6_icmp.c
ip6_input.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-12-09 21:43:31 -08:00
ip6_offload.c gso: validate gso_type on ipip style tunnels 2019-02-20 11:24:27 -08:00
ip6_offload.h
ip6_output.c ipv6: Fix dangling pointer when ipv6 fragment 2019-04-03 21:42:20 -07:00
ip6_tunnel.c ip6_tunnel: Match to ARPHRD_TUNNEL6 for dev type 2019-04-02 13:19:34 -07:00
ip6_udp_tunnel.c net/ipv6/udp_tunnel: prefer SO_BINDTOIFINDEX over SO_BINDTODEVICE 2019-01-17 14:55:52 -08:00
ip6_vti.c ip: validate header length on virtual device xmit 2019-01-01 12:05:02 -08:00
ip6mr.c ip6mr: Do not call __IP6_INC_STATS() from preemptible context 2019-03-04 10:55:48 -08:00
ipcomp6.c
ipv6_sockglue.c net: ipv6: add socket option IPV6_ROUTER_ALERT_ISOLATE 2019-03-03 21:05:10 -08:00
Kconfig
Makefile
mcast_snoop.c net: remove unneeded switch fall-through 2019-02-21 13:48:00 -08:00
mcast.c bridge: join all-snoopers multicast address 2019-01-22 17:18:08 -08:00
mip6.c
ndisc.c ipv6/ndisc: Preserve IPv6 control buffer if protocol error handlers are called 2018-10-26 15:58:06 -07:00
netfilter.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2019-02-18 11:38:30 -08:00
output_core.c
ping.c
proc.c
protocol.c
raw.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-12-20 11:53:36 -08:00
reassembly.c net: remove unused struct inet_frag_queue.fragments field 2019-02-26 08:27:05 -08:00
route.c ipv6: fix races in ip6_dst_destroy() 2019-04-30 23:38:38 -04:00
seg6_hmac.c
seg6_iptunnel.c ipv6: sr: clear IP6CB(skb) on SRH ip4ip6 encapsulation 2019-01-30 14:06:12 -08:00
seg6_local.c
seg6.c ipv6: propagate genlmsg_reply return code 2019-02-12 12:36:02 -05:00
sit.c ipv6: sit: reset ip header pointer in ipip6_rcv 2019-04-04 18:34:23 -07:00
syncookies.c
sysctl_net_ipv6.c
tcp_ipv6.c tcp: do not use ipv6 header for ipv4 flow 2019-03-19 14:00:27 -07:00
tcpv6_offload.c net: use indirect call wrappers at GRO transport layer 2018-12-15 13:23:02 -08:00
tunnel6.c net: Convert protocol error handlers from void to int 2018-11-08 17:13:08 -08:00
udp_impl.h udp6: add missing rehash callback to udplite 2019-01-17 15:01:08 -08:00
udp_offload.c net: use indirect call wrappers at GRO transport layer 2018-12-15 13:23:02 -08:00
udp.c udpv6: Check address length before reading address family 2019-04-12 10:25:03 -07:00
udplite.c udp6: add missing rehash callback to udplite 2019-01-17 15:01:08 -08:00
xfrm6_input.c net: use skb_sec_path helper in more places 2018-12-19 11:21:37 -08:00
xfrm6_mode_beet.c
xfrm6_mode_ro.c
xfrm6_mode_transport.c
xfrm6_mode_tunnel.c
xfrm6_output.c
xfrm6_policy.c xfrm6: remove BUG_ON from xfrm6_dst_ifdown 2018-11-22 07:55:48 +01:00
xfrm6_protocol.c net: Convert protocol error handlers from void to int 2018-11-08 17:13:08 -08:00
xfrm6_state.c
xfrm6_tunnel.c xfrm: clean up xfrm protocol checks 2019-03-26 08:35:36 +01:00