linux.git/net/ipv6, branch v4.0-rc4 Linux kernel source tree ip: fix error queue empty skb handling 2015-03-09T03:01:54+00:00 Willem de Bruijn willemb@google.com 2015-03-08T01:33:22+00:00 c247f0534cc5a5a547a343903f42295a471844e2 When reading from the error queue, msg_name and msg_control are only populated for some errors. A new exception for empty timestamp skbs added a false positive on icmp errors without payload. `traceroute -M udpconn` only displayed gateways that return payload with the icmp error: the embedded network headers are pulled before sock_queue_err_skb, leaving an skb with skb->len == 0 otherwise. Fix this regression by refining when msg_name and msg_control branches are taken. The solutions for the two fields are independent. msg_name only makes sense for errors that configure serr->port and serr->addr_offset. Test the first instead of skb->len. This also fixes another issue. saddr could hold the wrong data, as serr->addr_offset is not initialized in some code paths, pointing to the start of the network header. It is only valid when serr->port is set (non-zero). msg_control support differs between IPv4 and IPv6. IPv4 only honors requests for ICMP and timestamps with SOF_TIMESTAMPING_OPT_CMSG. The skb->len test can simply be removed, because skb->dev is also tested and never true for empty skbs. IPv6 honors requests for all errors aside from local errors and timestamps on empty skbs. In both cases, make the policy more explicit by moving this logic to a new function that decides whether to process msg_control and that optionally prepares the necessary fields in skb->cb[]. After this change, the IPv4 and IPv6 paths are more similar. The last case is rxrpc. Here, simply refine to only match timestamps. Fixes: 49ca0d8bfaf3 ("net-timestamp: no-payload option") Reported-by: Jan Niehusmann <jan@gondor.com> Signed-off-by: Willem de Bruijn <willemb@google.com> ---- Changes v1->v2 - fix local origin test inversion in ip6_datagram_support_cmsg - make v4 and v6 code paths more similar by introducing analogous ipv4_datagram_support_cmsg - fix compile bug in rxrpc Signed-off-by: David S. Miller <davem@davemloft.net> 
When reading from the error queue, msg_name and msg_control are only
populated for some errors. A new exception for empty timestamp skbs
added a false positive on icmp errors without payload.

`traceroute -M udpconn` only displayed gateways that return payload
with the icmp error: the embedded network headers are pulled before
sock_queue_err_skb, leaving an skb with skb->len == 0 otherwise.

Fix this regression by refining when msg_name and msg_control
branches are taken. The solutions for the two fields are independent.

msg_name only makes sense for errors that configure serr->port and
serr->addr_offset. Test the first instead of skb->len. This also fixes
another issue. saddr could hold the wrong data, as serr->addr_offset
is not initialized  in some code paths, pointing to the start of the
network header. It is only valid when serr->port is set (non-zero).

msg_control support differs between IPv4 and IPv6. IPv4 only honors
requests for ICMP and timestamps with SOF_TIMESTAMPING_OPT_CMSG. The
skb->len test can simply be removed, because skb->dev is also tested
and never true for empty skbs. IPv6 honors requests for all errors
aside from local errors and timestamps on empty skbs.

In both cases, make the policy more explicit by moving this logic to
a new function that decides whether to process msg_control and that
optionally prepares the necessary fields in skb->cb[]. After this
change, the IPv4 and IPv6 paths are more similar.

The last case is rxrpc. Here, simply refine to only match timestamps.

Fixes: 49ca0d8bfaf3 ("net-timestamp: no-payload option")

Reported-by: Jan Niehusmann <jan@gondor.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>

----

Changes
  v1->v2
  - fix local origin test inversion in ip6_datagram_support_cmsg
  - make v4 and v6 code paths more similar by introducing analogous
    ipv4_datagram_support_cmsg
  - fix compile bug in rxrpc
Signed-off-by: David S. Miller <davem@davemloft.net>
net: ping: Return EAFNOSUPPORT when appropriate. 2015-03-04T20:46:51+00:00 Lorenzo Colitti lorenzo@google.com 2015-03-03T14:16:16+00:00 9145736d4862145684009d6a72a6e61324a9439e 1. For an IPv4 ping socket, ping_check_bind_addr does not check the family of the socket address that's passed in. Instead, make it behave like inet_bind, which enforces either that the address family is AF_INET, or that the family is AF_UNSPEC and the address is 0.0.0.0. 2. For an IPv6 ping socket, ping_check_bind_addr returns EINVAL if the socket family is not AF_INET6. Return EAFNOSUPPORT instead, for consistency with inet6_bind. 3. Make ping_v4_sendmsg and ping_v6_sendmsg return EAFNOSUPPORT instead of EINVAL if an incorrect socket address structure is passed in. 4. Make IPv6 ping sockets be IPv6-only. The code does not support IPv4, and it cannot easily be made to support IPv4 because the protocol numbers for ICMP and ICMPv6 are different. This makes connect(::ffff:192.0.2.1) fail with EAFNOSUPPORT instead of making the socket unusable. Among other things, this fixes an oops that can be triggered by: int s = socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP); struct sockaddr_in6 sin6 = { .sin6_family = AF_INET6, .sin6_addr = in6addr_any, }; bind(s, (struct sockaddr *) &sin6, sizeof(sin6)); Change-Id: If06ca86d9f1e4593c0d6df174caca3487c57a241 Signed-off-by: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
1. For an IPv4 ping socket, ping_check_bind_addr does not check
   the family of the socket address that's passed in. Instead,
   make it behave like inet_bind, which enforces either that the
   address family is AF_INET, or that the family is AF_UNSPEC and
   the address is 0.0.0.0.
2. For an IPv6 ping socket, ping_check_bind_addr returns EINVAL
   if the socket family is not AF_INET6. Return EAFNOSUPPORT
   instead, for consistency with inet6_bind.
3. Make ping_v4_sendmsg and ping_v6_sendmsg return EAFNOSUPPORT
   instead of EINVAL if an incorrect socket address structure is
   passed in.
4. Make IPv6 ping sockets be IPv6-only. The code does not support
   IPv4, and it cannot easily be made to support IPv4 because
   the protocol numbers for ICMP and ICMPv6 are different. This
   makes connect(::ffff:192.0.2.1) fail with EAFNOSUPPORT instead
   of making the socket unusable.

Among other things, this fixes an oops that can be triggered by:

    int s = socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP);
    struct sockaddr_in6 sin6 = {
        .sin6_family = AF_INET6,
        .sin6_addr = in6addr_any,
    };
    bind(s, (struct sockaddr *) &sin6, sizeof(sin6));

Change-Id: If06ca86d9f1e4593c0d6df174caca3487c57a241
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
udp: only allow UFO for packets from SOCK_DGRAM sockets 2015-03-03T03:19:29+00:00 Michal Kubeček mkubecek@suse.cz 2015-03-02T17:27:11+00:00 acf8dd0a9d0b9e4cdb597c2f74802f79c699e802 If an over-MTU UDP datagram is sent through a SOCK_RAW socket to a UFO-capable device, ip_ufo_append_data() sets skb->ip_summed to CHECKSUM_PARTIAL unconditionally as all GSO code assumes transport layer checksum is to be computed on segmentation. However, in this case, skb->csum_start and skb->csum_offset are never set as raw socket transmit path bypasses udp_send_skb() where they are usually set. As a result, driver may access invalid memory when trying to calculate the checksum and store the result (as observed in virtio_net driver). Moreover, the very idea of modifying the userspace provided UDP header is IMHO against raw socket semantics (I wasn't able to find a document clearly stating this or the opposite, though). And while allowing CHECKSUM_NONE in the UFO case would be more efficient, it would be a bit too intrusive change just to handle a corner case like this. Therefore disallowing UFO for packets from SOCK_DGRAM seems to be the best option. Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net> 
If an over-MTU UDP datagram is sent through a SOCK_RAW socket to a
UFO-capable device, ip_ufo_append_data() sets skb->ip_summed to
CHECKSUM_PARTIAL unconditionally as all GSO code assumes transport layer
checksum is to be computed on segmentation. However, in this case,
skb->csum_start and skb->csum_offset are never set as raw socket
transmit path bypasses udp_send_skb() where they are usually set. As a
result, driver may access invalid memory when trying to calculate the
checksum and store the result (as observed in virtio_net driver).

Moreover, the very idea of modifying the userspace provided UDP header
is IMHO against raw socket semantics (I wasn't able to find a document
clearly stating this or the opposite, though). And while allowing
CHECKSUM_NONE in the UFO case would be more efficient, it would be a bit
too intrusive change just to handle a corner case like this. Therefore
disallowing UFO for packets from SOCK_DGRAM seems to be the best option.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
ipv6: addrconf: validate new MTU before applying it 2015-02-23T23:16:12+00:00 Marcelo Leitner mleitner@redhat.com 2015-02-23T14:17:13+00:00 77751427a1ff25b27d47a4c36b12c3c8667855ac Currently we don't check if the new MTU is valid or not and this allows one to configure a smaller than minimum allowed by RFCs or even bigger than interface own MTU, which is a problem as it may lead to packet drops. If you have a daemon like NetworkManager running, this may be exploited by remote attackers by forging RA packets with an invalid MTU, possibly leading to a DoS. (NetworkManager currently only validates for values too small, but not for too big ones.) The fix is just to make sure the new value is valid. That is, between IPV6_MIN_MTU and interface's MTU. Note that similar check is already performed at ndisc_router_discovery(), for when kernel itself parses the RA. Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net> 
Currently we don't check if the new MTU is valid or not and this allows
one to configure a smaller than minimum allowed by RFCs or even bigger
than interface own MTU, which is a problem as it may lead to packet
drops.

If you have a daemon like NetworkManager running, this may be exploited
by remote attackers by forging RA packets with an invalid MTU, possibly
leading to a DoS. (NetworkManager currently only validates for values
too small, but not for too big ones.)

The fix is just to make sure the new value is valid. That is, between
IPV6_MIN_MTU and interface's MTU.

Note that similar check is already performed at
ndisc_router_discovery(), for when kernel itself parses the RA.

Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
ipv6: fix ipv6_cow_metrics for non DST_HOST case 2015-02-15T04:26:16+00:00 Martin KaFai Lau kafai@fb.com 2015-02-13T00:14:08+00:00 3b4711757d7903ab6fa88a9e7ab8901b8227da60 ipv6_cow_metrics() currently assumes only DST_HOST routes require dynamic metrics allocation from inetpeer. The assumption breaks when ndisc discovered router with RTAX_MTU and RTAX_HOPLIMIT metric. Refer to ndisc_router_discovery() in ndisc.c and note that dst_metric_set() is called after the route is created. This patch creates the metrics array (by calling dst_cow_metrics_generic) in ipv6_cow_metrics(). Test: radvd.conf: interface qemubr0 { AdvLinkMTU 1300; AdvCurHopLimit 30; prefix fd00:face:face:face::/64 { AdvOnLink on; AdvAutonomous on; AdvRouterAddr off; }; }; Before: [root@qemu1 ~]# ip -6 r show | egrep -v unreachable fd00:face:face:face::/64 dev eth0 proto kernel metric 256 expires 27sec fe80::/64 dev eth0 proto kernel metric 256 default via fe80::74df:d0ff:fe23:8ef2 dev eth0 proto ra metric 1024 expires 27sec After: [root@qemu1 ~]# ip -6 r show | egrep -v unreachable fd00:face:face:face::/64 dev eth0 proto kernel metric 256 expires 27sec mtu 1300 fe80::/64 dev eth0 proto kernel metric 256 mtu 1300 default via fe80::74df:d0ff:fe23:8ef2 dev eth0 proto ra metric 1024 expires 27sec mtu 1300 hoplimit 30 Fixes: 8e2ec639173f325 (ipv6: don't use inetpeer to store metrics for routes.) Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
ipv6_cow_metrics() currently assumes only DST_HOST routes require
dynamic metrics allocation from inetpeer.  The assumption breaks
when ndisc discovered router with RTAX_MTU and RTAX_HOPLIMIT metric.
Refer to ndisc_router_discovery() in ndisc.c and note that dst_metric_set()
is called after the route is created.

This patch creates the metrics array (by calling dst_cow_metrics_generic) in
ipv6_cow_metrics().

Test:
radvd.conf:
interface qemubr0
{
	AdvLinkMTU 1300;
	AdvCurHopLimit 30;

	prefix fd00:face:face:face::/64
	{
		AdvOnLink on;
		AdvAutonomous on;
		AdvRouterAddr off;
	};
};

Before:
[root@qemu1 ~]# ip -6 r show | egrep -v unreachable
fd00:face:face:face::/64 dev eth0  proto kernel  metric 256  expires 27sec
fe80::/64 dev eth0  proto kernel  metric 256
default via fe80::74df:d0ff:fe23:8ef2 dev eth0  proto ra  metric 1024  expires 27sec

After:
[root@qemu1 ~]# ip -6 r show | egrep -v unreachable
fd00:face:face:face::/64 dev eth0  proto kernel  metric 256  expires 27sec mtu 1300
fe80::/64 dev eth0  proto kernel  metric 256  mtu 1300
default via fe80::74df:d0ff:fe23:8ef2 dev eth0  proto ra  metric 1024  expires 27sec mtu 1300 hoplimit 30

Fixes: 8e2ec639173f325 (ipv6: don't use inetpeer to store metrics for routes.)
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ipv6: fix possible deadlock in ip6_fl_purge / ip6_fl_gc 2015-02-12T15:13:03+00:00 Jan Stancek jstancek@redhat.com 2015-02-11T13:06:23+00:00 4762fb980465463734f02c67c67f40beb8903f73 Use spin_lock_bh in ip6_fl_purge() to prevent following potentially deadlock scenario between ip6_fl_purge() and ip6_fl_gc() timer. ================================= [ INFO: inconsistent lock state ] 3.19.0 #1 Not tainted --------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/5/0 [HC0[0]:SC1[1]:HE1:SE0] takes: (ip6_fl_lock){+.?...}, at: [<ffffffff8171155d>] ip6_fl_gc+0x2d/0x180 {SOFTIRQ-ON-W} state was registered at: [<ffffffff810ee9a0>] __lock_acquire+0x4a0/0x10b0 [<ffffffff810efd54>] lock_acquire+0xc4/0x2b0 [<ffffffff81751d2d>] _raw_spin_lock+0x3d/0x80 [<ffffffff81711798>] ip6_flowlabel_net_exit+0x28/0x110 [<ffffffff815f9759>] ops_exit_list.isra.1+0x39/0x60 [<ffffffff815fa320>] cleanup_net+0x100/0x1e0 [<ffffffff810ad80a>] process_one_work+0x20a/0x830 [<ffffffff810adf4b>] worker_thread+0x11b/0x460 [<ffffffff810b42f4>] kthread+0x104/0x120 [<ffffffff81752bfc>] ret_from_fork+0x7c/0xb0 irq event stamp: 84640 hardirqs last enabled at (84640): [<ffffffff81752080>] _raw_spin_unlock_irq+0x30/0x50 hardirqs last disabled at (84639): [<ffffffff81751eff>] _raw_spin_lock_irq+0x1f/0x80 softirqs last enabled at (84628): [<ffffffff81091ad1>] _local_bh_enable+0x21/0x50 softirqs last disabled at (84629): [<ffffffff81093b7d>] irq_exit+0x12d/0x150 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(ip6_fl_lock); <Interrupt> lock(ip6_fl_lock); *** DEADLOCK *** Signed-off-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Use spin_lock_bh in ip6_fl_purge() to prevent following potentially
deadlock scenario between ip6_fl_purge() and ip6_fl_gc() timer.

  =================================
  [ INFO: inconsistent lock state ]
  3.19.0 #1 Not tainted
  ---------------------------------
  inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
  swapper/5/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
   (ip6_fl_lock){+.?...}, at: [<ffffffff8171155d>] ip6_fl_gc+0x2d/0x180
  {SOFTIRQ-ON-W} state was registered at:
    [<ffffffff810ee9a0>] __lock_acquire+0x4a0/0x10b0
    [<ffffffff810efd54>] lock_acquire+0xc4/0x2b0
    [<ffffffff81751d2d>] _raw_spin_lock+0x3d/0x80
    [<ffffffff81711798>] ip6_flowlabel_net_exit+0x28/0x110
    [<ffffffff815f9759>] ops_exit_list.isra.1+0x39/0x60
    [<ffffffff815fa320>] cleanup_net+0x100/0x1e0
    [<ffffffff810ad80a>] process_one_work+0x20a/0x830
    [<ffffffff810adf4b>] worker_thread+0x11b/0x460
    [<ffffffff810b42f4>] kthread+0x104/0x120
    [<ffffffff81752bfc>] ret_from_fork+0x7c/0xb0
  irq event stamp: 84640
  hardirqs last  enabled at (84640): [<ffffffff81752080>] _raw_spin_unlock_irq+0x30/0x50
  hardirqs last disabled at (84639): [<ffffffff81751eff>] _raw_spin_lock_irq+0x1f/0x80
  softirqs last  enabled at (84628): [<ffffffff81091ad1>] _local_bh_enable+0x21/0x50
  softirqs last disabled at (84629): [<ffffffff81093b7d>] irq_exit+0x12d/0x150

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(ip6_fl_lock);
    <Interrupt>
      lock(ip6_fl_lock);

   *** DEADLOCK ***

Signed-off-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
udp: Set SKB_GSO_UDP_TUNNEL* in UDP GRO path 2015-02-11T23:12:10+00:00 Tom Herbert therbert@google.com 2015-02-11T00:30:29+00:00 6db93ea13b7937c0523ea1f977b322f1347a5633 Properly set GSO types and skb->encapsulation in the UDP tunnel GRO complete so that packets are properly represented for GSO. This sets SKB_GSO_UDP_TUNNEL or SKB_GSO_UDP_TUNNEL_CSUM depending on whether non-zero checksums were received, and sets SKB_GSO_TUNNEL_REMCSUM if the remote checksum option was processed. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Properly set GSO types and skb->encapsulation in the UDP tunnel GRO
complete so that packets are properly represented for GSO. This sets
SKB_GSO_UDP_TUNNEL or SKB_GSO_UDP_TUNNEL_CSUM depending on whether
non-zero checksums were received, and sets SKB_GSO_TUNNEL_REMCSUM if
the remote checksum option was processed.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ipv6: Partial checksum only UDP packets 2015-02-11T22:32:08+00:00 Vlad Yasevich vyasevich@gmail.com 2015-02-10T16:37:29+00:00 bf250a1fa769f2eb8fc7a4e28b3b523e9cb67eef ip6_append_data is used by other protocols and some of them can't be partially checksummed. Only partially checksum UDP protocol. Fixes: 32dce968dd987a (ipv6: Allow for partial checksums on non-ufo packets) Reported-by: Sabrina Dubroca <sd@queasysnail.net> Tested-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
ip6_append_data is used by other protocols and some of them can't
be partially checksummed.  Only partially checksum UDP protocol.

Fixes: 32dce968dd987a (ipv6: Allow for partial checksums on non-ufo packets)
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Tested-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-02-09T22:35:57+00:00 David S. Miller davem@davemloft.net 2015-02-09T22:35:57+00:00 2573beec56aa28a0e6d4430fb6796d0c76308bcf Signed-off-by: David S. Miller <davem@davemloft.net> 
Signed-off-by: David S. Miller <davem@davemloft.net>
ipv6: Make __ipv6_select_ident static 2015-02-09T22:21:03+00:00 Vlad Yasevich vyasevich@gmail.com 2015-02-09T14:38:21+00:00 8381eacf5c3b35cf7755f4bc521c4d56d24c1cd9 Make __ipv6_select_ident() static as it isn't used outside the file. Fixes: 0508c07f5e0c9 (ipv6: Select fragment id during UFO segmentation if not set.) Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Make __ipv6_select_ident() static as it isn't used outside
the file.

Fixes: 0508c07f5e0c9 (ipv6: Select fragment id during UFO segmentation if not set.)
Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>