kernel_optimize_test/net/ipv4
Alexander Potapenko 86f4c90a1c ipv4, ipv6: ensure raw socket message is big enough to hold an IP header
raw_send_hdrinc() and rawv6_send_hdrinc() expect that the buffer copied
from the userspace contains the IPv4/IPv6 header, so if too few bytes are
copied, parts of the header may remain uninitialized.

This bug has been detected with KMSAN.

For the record, the KMSAN report:

==================================================================
BUG: KMSAN: use of unitialized memory in nf_ct_frag6_gather+0xf5a/0x44a0
inter: 0
CPU: 0 PID: 1036 Comm: probe Not tainted 4.11.0-rc5+ #2455
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16
 dump_stack+0x143/0x1b0 lib/dump_stack.c:52
 kmsan_report+0x16b/0x1e0 mm/kmsan/kmsan.c:1078
 __kmsan_warning_32+0x5c/0xa0 mm/kmsan/kmsan_instr.c:510
 nf_ct_frag6_gather+0xf5a/0x44a0 net/ipv6/netfilter/nf_conntrack_reasm.c:577
 ipv6_defrag+0x1d9/0x280 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c:68
 nf_hook_entry_hookfn ./include/linux/netfilter.h:102
 nf_hook_slow+0x13f/0x3c0 net/netfilter/core.c:310
 nf_hook ./include/linux/netfilter.h:212
 NF_HOOK ./include/linux/netfilter.h:255
 rawv6_send_hdrinc net/ipv6/raw.c:673
 rawv6_sendmsg+0x2fcb/0x41a0 net/ipv6/raw.c:919
 inet_sendmsg+0x3f8/0x6d0 net/ipv4/af_inet.c:762
 sock_sendmsg_nosec net/socket.c:633
 sock_sendmsg net/socket.c:643
 SYSC_sendto+0x6a5/0x7c0 net/socket.c:1696
 SyS_sendto+0xbc/0xe0 net/socket.c:1664
 do_syscall_64+0x72/0xa0 arch/x86/entry/common.c:285
 entry_SYSCALL64_slow_path+0x25/0x25 arch/x86/entry/entry_64.S:246
RIP: 0033:0x436e03
RSP: 002b:00007ffce48baf38 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00000000004002b0 RCX: 0000000000436e03
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007ffce48baf90 R08: 00007ffce48baf50 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000401790 R14: 0000000000401820 R15: 0000000000000000
origin: 00000000d9400053
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:362
 kmsan_internal_poison_shadow+0xb1/0x1a0 mm/kmsan/kmsan.c:257
 kmsan_poison_shadow+0x6d/0xc0 mm/kmsan/kmsan.c:270
 slab_alloc_node mm/slub.c:2735
 __kmalloc_node_track_caller+0x1f4/0x390 mm/slub.c:4341
 __kmalloc_reserve net/core/skbuff.c:138
 __alloc_skb+0x2cd/0x740 net/core/skbuff.c:231
 alloc_skb ./include/linux/skbuff.h:933
 alloc_skb_with_frags+0x209/0xbc0 net/core/skbuff.c:4678
 sock_alloc_send_pskb+0x9ff/0xe00 net/core/sock.c:1903
 sock_alloc_send_skb+0xe4/0x100 net/core/sock.c:1920
 rawv6_send_hdrinc net/ipv6/raw.c:638
 rawv6_sendmsg+0x2918/0x41a0 net/ipv6/raw.c:919
 inet_sendmsg+0x3f8/0x6d0 net/ipv4/af_inet.c:762
 sock_sendmsg_nosec net/socket.c:633
 sock_sendmsg net/socket.c:643
 SYSC_sendto+0x6a5/0x7c0 net/socket.c:1696
 SyS_sendto+0xbc/0xe0 net/socket.c:1664
 do_syscall_64+0x72/0xa0 arch/x86/entry/common.c:285
 return_from_SYSCALL_64+0x0/0x6a arch/x86/entry/entry_64.S:246
==================================================================

, triggered by the following syscalls:
  socket(PF_INET6, SOCK_RAW, IPPROTO_RAW) = 3
  sendto(3, NULL, 0, 0, {sa_family=AF_INET6, sin6_port=htons(0), inet_pton(AF_INET6, "ff00::", &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, 28) = -1 EPERM

A similar report is triggered in net/ipv4/raw.c if we use a PF_INET socket
instead of a PF_INET6 one.

Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-04 11:02:46 -04:00
..
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2017-05-01 10:47:53 -04:00
af_inet.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-05-02 16:40:27 -07:00
ah4.c
arp.c
cipso_ipv4.c
datagram.c
devinet.c
esp4_offload.c
esp4.c net/esp4: Fix invalid esph pointer crash 2017-05-01 14:58:50 -04:00
fib_frontend.c net: fib: Decrease one unnecessary rt cache flush in fib_disable_ip 2017-04-27 16:33:30 -04:00
fib_lookup.h
fib_notifier.c
fib_rules.c
fib_semantics.c
fib_trie.c
fou.c
gre_demux.c
gre_offload.c
icmp.c
igmp.c
inet_connection_sock.c
inet_diag.c
inet_fragment.c
inet_hashtables.c
inet_timewait_sock.c
inetpeer.c
ip_forward.c
ip_fragment.c
ip_gre.c
ip_input.c
ip_options.c
ip_output.c
ip_sockglue.c ipv4: get rid of ip_ra_lock 2017-04-30 22:44:04 -04:00
ip_tunnel_core.c
ip_tunnel.c
ip_vti.c
ipcomp.c
ipconfig.c
ipip.c
ipmr.c
Kconfig
Makefile
netfilter.c
ping.c
proc.c net/tcp_fastopen: Add snmp counter for blackhole detection 2017-04-24 14:27:17 -04:00
protocol.c
raw_diag.c
raw.c ipv4, ipv6: ensure raw socket message is big enough to hold an IP header 2017-05-04 11:02:46 -04:00
route.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-04-26 22:39:08 -04:00
syncookies.c
sysctl_net_ipv4.c net/tcp_fastopen: Disable active side TFO in certain scenarios 2017-04-24 14:27:17 -04:00
tcp_bbr.c
tcp_bic.c
tcp_cdg.c
tcp_cong.c tcp: memset ca_priv data to 0 properly 2017-04-26 14:58:32 -04:00
tcp_cubic.c
tcp_dctcp.c
tcp_diag.c
tcp_fastopen.c net/tcp_fastopen: Add snmp counter for blackhole detection 2017-04-24 14:27:17 -04:00
tcp_highspeed.c
tcp_htcp.c
tcp_hybla.c
tcp_illinois.c
tcp_input.c tcp: switch rcv_rtt_est and rcvq_space to high resolution timestamps 2017-04-26 14:44:39 -04:00
tcp_ipv4.c net/tcp_fastopen: Disable active side TFO in certain scenarios 2017-04-24 14:27:17 -04:00
tcp_lp.c tcp: fix wraparound issue in tcp_lp 2017-05-02 15:07:02 -04:00
tcp_metrics.c
tcp_minisocks.c tcp: do not inherit fastopen_req from parent 2017-05-04 11:00:04 -04:00
tcp_nv.c
tcp_offload.c
tcp_output.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-05-02 16:40:27 -07:00
tcp_probe.c
tcp_rate.c tcp: do not pass timestamp to tcp_rate_gen() 2017-04-26 14:44:38 -04:00
tcp_recovery.c tcp: tcp_rack_reo_timeout() must update tp->tcp_mstamp 2017-04-27 11:46:15 -04:00
tcp_scalable.c
tcp_timer.c net/tcp_fastopen: Remove mss check in tcp_write_timeout() 2017-04-24 14:27:17 -04:00
tcp_vegas.c
tcp_vegas.h
tcp_veno.c
tcp_westwood.c
tcp_yeah.c
tcp.c tcp: fix access to sk->sk_state in tcp_poll() 2017-04-30 22:24:16 -04:00
tunnel4.c
udp_diag.c
udp_impl.h
udp_offload.c udp: disable inner UDP checksum offloads in IPsec case 2017-04-24 13:48:54 -04:00
udp_tunnel.c
udp.c
udplite.c
xfrm4_input.c
xfrm4_mode_beet.c
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c
xfrm4_output.c
xfrm4_policy.c
xfrm4_protocol.c
xfrm4_state.c
xfrm4_tunnel.c