litmus-rt-ext-res.git/net/ipv4, branch EXT-RES

ipv4, ipv6: ensure raw socket message is big enough to hold an IP header

2017-05-14T12:00:21+00:00

[ Upstream commit 86f4c90a1c5c1493f07f2d12c1079f5bf01936f2 ]

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 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: do not inherit fastopen_req from parent

2017-05-14T12:00:21+00:00

[ Upstream commit 8b485ce69876c65db12ed390e7f9c0d2a64eff2c ]

Under fuzzer stress, it is possible that a child gets a non NULL
fastopen_req pointer from its parent at accept() time, when/if parent
morphs from listener to active session.

We need to make sure this can not happen, by clearing the field after
socket cloning.

BUG: Double free or freeing an invalid pointer
Unexpected shadow byte: 0xFB
CPU: 3 PID: 20933 Comm: syz-executor3 Not tainted 4.11.0+ #306
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
01/01/2011
Call Trace:
 
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x292/0x395 lib/dump_stack.c:52
 kasan_object_err+0x1c/0x70 mm/kasan/report.c:164
 kasan_report_double_free+0x5c/0x70 mm/kasan/report.c:185
 kasan_slab_free+0x9d/0xc0 mm/kasan/kasan.c:580
 slab_free_hook mm/slub.c:1357 [inline]
 slab_free_freelist_hook mm/slub.c:1379 [inline]
 slab_free mm/slub.c:2961 [inline]
 kfree+0xe8/0x2b0 mm/slub.c:3882
 tcp_free_fastopen_req net/ipv4/tcp.c:1077 [inline]
 tcp_disconnect+0xc15/0x13e0 net/ipv4/tcp.c:2328
 inet_child_forget+0xb8/0x600 net/ipv4/inet_connection_sock.c:898
 inet_csk_reqsk_queue_add+0x1e7/0x250
net/ipv4/inet_connection_sock.c:928
 tcp_get_cookie_sock+0x21a/0x510 net/ipv4/syncookies.c:217
 cookie_v4_check+0x1a19/0x28b0 net/ipv4/syncookies.c:384
 tcp_v4_cookie_check net/ipv4/tcp_ipv4.c:1384 [inline]
 tcp_v4_do_rcv+0x731/0x940 net/ipv4/tcp_ipv4.c:1421
 tcp_v4_rcv+0x2dc0/0x31c0 net/ipv4/tcp_ipv4.c:1715
 ip_local_deliver_finish+0x4cc/0xc20 net/ipv4/ip_input.c:216
 NF_HOOK include/linux/netfilter.h:257 [inline]
 ip_local_deliver+0x1ce/0x700 net/ipv4/ip_input.c:257
 dst_input include/net/dst.h:492 [inline]
 ip_rcv_finish+0xb1d/0x20b0 net/ipv4/ip_input.c:396
 NF_HOOK include/linux/netfilter.h:257 [inline]
 ip_rcv+0xd8c/0x19c0 net/ipv4/ip_input.c:487
 __netif_receive_skb_core+0x1ad1/0x3400 net/core/dev.c:4210
 __netif_receive_skb+0x2a/0x1a0 net/core/dev.c:4248
 process_backlog+0xe5/0x6c0 net/core/dev.c:4868
 napi_poll net/core/dev.c:5270 [inline]
 net_rx_action+0xe70/0x18e0 net/core/dev.c:5335
 __do_softirq+0x2fb/0xb99 kernel/softirq.c:284
 do_softirq_own_stack+0x1c/0x30 arch/x86/entry/entry_64.S:899
 
 do_softirq.part.17+0x1e8/0x230 kernel/softirq.c:328
 do_softirq kernel/softirq.c:176 [inline]
 __local_bh_enable_ip+0x1cf/0x1e0 kernel/softirq.c:181
 local_bh_enable include/linux/bottom_half.h:31 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:931 [inline]
 ip_finish_output2+0x9ab/0x15e0 net/ipv4/ip_output.c:230
 ip_finish_output+0xa35/0xdf0 net/ipv4/ip_output.c:316
 NF_HOOK_COND include/linux/netfilter.h:246 [inline]
 ip_output+0x1f6/0x7b0 net/ipv4/ip_output.c:404
 dst_output include/net/dst.h:486 [inline]
 ip_local_out+0x95/0x160 net/ipv4/ip_output.c:124
 ip_queue_xmit+0x9a8/0x1a10 net/ipv4/ip_output.c:503
 tcp_transmit_skb+0x1ade/0x3470 net/ipv4/tcp_output.c:1057
 tcp_write_xmit+0x79e/0x55b0 net/ipv4/tcp_output.c:2265
 __tcp_push_pending_frames+0xfa/0x3a0 net/ipv4/tcp_output.c:2450
 tcp_push+0x4ee/0x780 net/ipv4/tcp.c:683
 tcp_sendmsg+0x128d/0x39b0 net/ipv4/tcp.c:1342
 inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:762
 sock_sendmsg_nosec net/socket.c:633 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:643
 SYSC_sendto+0x660/0x810 net/socket.c:1696
 SyS_sendto+0x40/0x50 net/socket.c:1664
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x446059
RSP: 002b:00007faa6761fb58 EFLAGS: 00000282 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000017 RCX: 0000000000446059
RDX: 0000000000000001 RSI: 0000000020ba3fcd RDI: 0000000000000017
RBP: 00000000006e40a0 R08: 0000000020ba4ff0 R09: 0000000000000010
R10: 0000000020000000 R11: 0000000000000282 R12: 0000000000708150
R13: 0000000000000000 R14: 00007faa676209c0 R15: 00007faa67620700
Object at ffff88003b5bbcb8, in cache kmalloc-64 size: 64
Allocated:
PID = 20909
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:513
 set_track mm/kasan/kasan.c:525 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:616
 kmem_cache_alloc_trace+0x82/0x270 mm/slub.c:2745
 kmalloc include/linux/slab.h:490 [inline]
 kzalloc include/linux/slab.h:663 [inline]
 tcp_sendmsg_fastopen net/ipv4/tcp.c:1094 [inline]
 tcp_sendmsg+0x221a/0x39b0 net/ipv4/tcp.c:1139
 inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:762
 sock_sendmsg_nosec net/socket.c:633 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:643
 SYSC_sendto+0x660/0x810 net/socket.c:1696
 SyS_sendto+0x40/0x50 net/socket.c:1664
 entry_SYSCALL_64_fastpath+0x1f/0xbe
Freed:
PID = 20909
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:513
 set_track mm/kasan/kasan.c:525 [inline]
 kasan_slab_free+0x73/0xc0 mm/kasan/kasan.c:589
 slab_free_hook mm/slub.c:1357 [inline]
 slab_free_freelist_hook mm/slub.c:1379 [inline]
 slab_free mm/slub.c:2961 [inline]
 kfree+0xe8/0x2b0 mm/slub.c:3882
 tcp_free_fastopen_req net/ipv4/tcp.c:1077 [inline]
 tcp_disconnect+0xc15/0x13e0 net/ipv4/tcp.c:2328
 __inet_stream_connect+0x20c/0xf90 net/ipv4/af_inet.c:593
 tcp_sendmsg_fastopen net/ipv4/tcp.c:1111 [inline]
 tcp_sendmsg+0x23a8/0x39b0 net/ipv4/tcp.c:1139
 inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:762
 sock_sendmsg_nosec net/socket.c:633 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:643
 SYSC_sendto+0x660/0x810 net/socket.c:1696
 SyS_sendto+0x40/0x50 net/socket.c:1664
 entry_SYSCALL_64_fastpath+0x1f/0xbe

Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets")
Fixes: 7db92362d2fe ("tcp: fix potential double free issue for fastopen_req")
Signed-off-by: Eric Dumazet 
Reported-by: Andrey Konovalov 
Acked-by: Wei Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: fix wraparound issue in tcp_lp

2017-05-14T12:00:21+00:00

[ Upstream commit a9f11f963a546fea9144f6a6d1a307e814a387e7 ]

Be careful when comparing tcp_time_stamp to some u32 quantity,
otherwise result can be surprising.

Fixes: 7c106d7e782b ("[TCP]: TCP Low Priority congestion control")
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: do not underestimate skb->truesize in tcp_trim_head()

2017-05-14T12:00:20+00:00

[ Upstream commit 7162fb242cb8322beb558828fd26b33c3e9fc805 ]

Andrey found a way to trigger the WARN_ON_ONCE(delta < len) in
skb_try_coalesce() using syzkaller and a filter attached to a TCP
socket over loopback interface.

I believe one issue with looped skbs is that tcp_trim_head() can end up
producing skb with under estimated truesize.

It hardly matters for normal conditions, since packets sent over
loopback are never truncated.

Bytes trimmed from skb->head should not change skb truesize, since
skb->head is not reallocated.

Signed-off-by: Eric Dumazet 
Reported-by: Andrey Konovalov 
Tested-by: Andrey Konovalov 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: memset ca_priv data to 0 properly

2017-05-03T15:36:37+00:00

[ Upstream commit c1201444075009507a6818de6518e2822b9a87c8 ]

Always zero out ca_priv data in tcp_assign_congestion_control() so that
ca_priv data is cleared out during socket creation.
Also always zero out ca_priv data in tcp_reinit_congestion_control() so
that when cc algorithm is changed, ca_priv data is cleared out as well.
We should still zero out ca_priv data even in TCP_CLOSE state because
user could call connect() on AF_UNSPEC to disconnect the socket and
leave it in TCP_CLOSE state and later call setsockopt() to switch cc
algorithm on this socket.

Fixes: 2b0a8c9ee ("tcp: add CDG congestion control")
Reported-by: Andrey Konovalov  
Signed-off-by: Wei Wang 
Acked-by: Eric Dumazet 
Acked-by: Yuchung Cheng 
Acked-by: Neal Cardwell 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net-timestamp: avoid use-after-free in ip_recv_error

2017-05-03T15:36:36+00:00

[ Upstream commit 1862d6208db0aeca9c8ace44915b08d5ab2cd667 ]

Syzkaller reported a use-after-free in ip_recv_error at line

    info->ipi_ifindex = skb->dev->ifindex;

This function is called on dequeue from the error queue, at which
point the device pointer may no longer be valid.

Save ifindex on enqueue in __skb_complete_tx_timestamp, when the
pointer is valid or NULL. Store it in temporary storage skb->cb.

It is safe to reference skb->dev here, as called from device drivers
or dev_queue_xmit. The exception is when called from tcp_ack_tstamp;
in that case it is NULL and ifindex is set to 0 (invalid).

Do not return a pktinfo cmsg if ifindex is 0. This maintains the
current behavior of not returning a cmsg if skb->dev was NULL.

On dequeue, the ipv4 path will cast from sock_exterr_skb to
in_pktinfo. Both have ifindex as their first element, so no explicit
conversion is needed. This is by design, introduced in commit
0b922b7a829c ("net: original ingress device index in PKTINFO"). For
ipv6 ip6_datagram_support_cmsg converts to in6_pktinfo.

Fixes: 829ae9d61165 ("net-timestamp: allow reading recv cmsg on errqueue with origin tstamp")
Reported-by: Andrey Konovalov 
Signed-off-by: Willem de Bruijn 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: clear saved_syn in tcp_disconnect()

2017-05-03T15:36:35+00:00

[ Upstream commit 17c3060b1701fc69daedb4c90be6325d3d9fca8e ]

In the (very unlikely) case a passive socket becomes a listener,
we do not want to duplicate its saved SYN headers.

This would lead to double frees, use after free, and please hackers and
various fuzzers

Tested:
    0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
   +0 setsockopt(3, IPPROTO_TCP, TCP_SAVE_SYN, [1], 4) = 0
   +0 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0

   +0 bind(3, ..., ...) = 0
   +0 listen(3, 5) = 0

   +0 < S 0:0(0) win 32972 
   +0 > S. 0:0(0) ack 1 <...>
  +.1 < . 1:1(0) ack 1 win 257
   +0 accept(3, ..., ...) = 4

   +0 connect(4, AF_UNSPEC, ...) = 0
   +0 close(3) = 0
   +0 bind(4, ..., ...) = 0
   +0 listen(4, 5) = 0

   +0 < S 0:0(0) win 32972 
   +0 > S. 0:0(0) ack 1 <...>
  +.1 < . 1:1(0) ack 1 win 257

Fixes: cd8ae85299d5 ("tcp: provide SYN headers for passive connections")
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipv4: fix multipath RTM_GETROUTE behavior when iif is given

2017-05-03T15:36:35+00:00

[ Upstream commit a8801799c6975601fd58ae62f48964caec2eb83f ]

inet_rtm_getroute synthesizes a skeletal ICMP skb, which is passed to
ip_route_input when iif is given. If a multipath route is present for
the designated destination, ip_multipath_icmp_hash ends up being called,
which uses the source/destination addresses within the skb to calculate
a hash. However, those are not set in the synthetic skb, causing it to
return an arbitrary and incorrect result.

Instead, use UDP, which gets no such special treatment.

Signed-off-by: Florian Larysch 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ping: implement proper locking

2017-05-03T15:36:34+00:00

commit 43a6684519ab0a6c52024b5e25322476cabad893 upstream.

We got a report of yet another bug in ping

http://www.openwall.com/lists/oss-security/2017/03/24/6

->disconnect() is not called with socket lock held.

Fix this by acquiring ping rwlock earlier.

Thanks to Daniel, Alexander and Andrey for letting us know this problem.

Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind")
Signed-off-by: Eric Dumazet 
Reported-by: Daniel Jiang 
Reported-by: Solar Designer 
Reported-by: Andrey Konovalov 
Signed-off-by: David S. Miller 
Cc: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

tcp: initialize icsk_ack.lrcvtime at session start time

2017-03-30T07:41:22+00:00

[ Upstream commit 15bb7745e94a665caf42bfaabf0ce062845b533b ]

icsk_ack.lrcvtime has a 0 value at socket creation time.

tcpi_last_data_recv can have bogus value if no payload is ever received.

This patch initializes icsk_ack.lrcvtime for active sessions
in tcp_finish_connect(), and for passive sessions in
tcp_create_openreq_child()

Signed-off-by: Eric Dumazet 
Acked-by: Neal Cardwell 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman