linux-stable.git/net/sctp/protocol.c, branch v4.7 Linux kernel stable tree sctp: fix copying more bytes than expected in sctp_add_bind_addr 2016-03-08T20:04:08+00:00 Marcelo Ricardo Leitner marcelo.leitner@gmail.com 2016-03-08T13:34:28+00:00 133800d1f0288b9ddfc0d0aded10d9efa82d5b8c Dmitry reported that sctp_add_bind_addr may read more bytes than expected in case the parameter is a IPv4 addr supplied by the user through calls such as sctp_bindx_add(), because it always copies sizeof(union sctp_addr) while the buffer may be just a struct sockaddr_in, which is smaller. This patch then fixes it by limiting the memcpy to the min between the union size and a (new parameter) provided addr size. Where possible this parameter still is the size of that union, except for reading from user-provided buffers, which then it accounts for protocol type. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Dmitry reported that sctp_add_bind_addr may read more bytes than
expected in case the parameter is a IPv4 addr supplied by the user
through calls such as sctp_bindx_add(), because it always copies
sizeof(union sctp_addr) while the buffer may be just a struct
sockaddr_in, which is smaller.

This patch then fixes it by limiting the memcpy to the min between the
union size and a (new parameter) provided addr size. Where possible this
parameter still is the size of that union, except for reading from
user-provided buffers, which then it accounts for protocol type.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sctp: Fix port hash table size computation 2016-02-22T02:52:51+00:00 Neil Horman nhorman@tuxdriver.com 2016-02-18T21:10:57+00:00 d9749fb5942f51555dc9ce1ac0dbb1806960a975 Dmitry Vyukov noted recently that the sctp_port_hashtable had an error in its size computation, observing that the current method never guaranteed that the hashsize (measured in number of entries) would be a power of two, which the input hash function for that table requires. The root cause of the problem is that two values need to be computed (one, the allocation order of the storage requries, as passed to __get_free_pages, and two the number of entries for the hash table). Both need to be ^2, but for different reasons, and the existing code is simply computing one order value, and using it as the basis for both, which is wrong (i.e. it assumes that ((1<<order)*PAGE_SIZE)/sizeof(bucket) is still ^2 when its not). To fix this, we change the logic slightly. We start by computing a goal allocation order (which is limited by the maximum size hash table we want to support. Then we attempt to allocate that size table, decreasing the order until a successful allocation is made. Then, with the resultant successful order we compute the number of buckets that hash table supports, which we then round down to the nearest power of two, giving us the number of entries the table actually supports. I've tested this locally here, using non-debug and spinlock-debug kernels, and the number of entries in the hashtable consistently work out to be powers of two in all cases. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> CC: Dmitry Vyukov <dvyukov@google.com> CC: Vladislav Yasevich <vyasevich@gmail.com> CC: "David S. Miller" <davem@davemloft.net> Signed-off-by: David S. Miller <davem@davemloft.net> 
Dmitry Vyukov noted recently that the sctp_port_hashtable had an error in
its size computation, observing that the current method never guaranteed
that the hashsize (measured in number of entries) would be a power of two,
which the input hash function for that table requires.  The root cause of
the problem is that two values need to be computed (one, the allocation
order of the storage requries, as passed to __get_free_pages, and two the
number of entries for the hash table).  Both need to be ^2, but for
different reasons, and the existing code is simply computing one order
value, and using it as the basis for both, which is wrong (i.e. it assumes
that ((1<<order)*PAGE_SIZE)/sizeof(bucket) is still ^2 when its not).

To fix this, we change the logic slightly.  We start by computing a goal
allocation order (which is limited by the maximum size hash table we want
to support.  Then we attempt to allocate that size table, decreasing the
order until a successful allocation is made.  Then, with the resultant
successful order we compute the number of buckets that hash table supports,
which we then round down to the nearest power of two, giving us the number
of entries the table actually supports.

I've tested this locally here, using non-debug and spinlock-debug kernels,
and the number of entries in the hashtable consistently work out to be
powers of two in all cases.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
CC: Dmitry Vyukov <dvyukov@google.com>
CC: Vladislav Yasevich <vyasevich@gmail.com>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
sctp: drop the old assoc hashtable of sctp 2016-01-05T17:24:01+00:00 Xin Long lucien.xin@gmail.com 2015-12-30T15:50:49+00:00 b5eff7128366c4a7a9b502097a968ec9cae2bea2 transport hashtable will replace the association hashtable, so association hashtable is not used in sctp any more, so drop the codes about that. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
transport hashtable will replace the association hashtable,
so association hashtable is not used in sctp any more, so
drop the codes about that.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sctp: apply rhashtable api to send/recv path 2016-01-05T17:24:01+00:00 Xin Long lucien.xin@gmail.com 2015-12-30T15:50:47+00:00 4f0087812648b7611157ae22954acfaed820d24e apply lookup apis to two functions, for __sctp_endpoint_lookup_assoc and __sctp_lookup_association, it's invoked in the protection of sock lock, it will be safe, but sctp_lookup_association need to call rcu_read_lock() and to detect the t->dead to protect it. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
apply lookup apis to two functions, for __sctp_endpoint_lookup_assoc
and __sctp_lookup_association, it's invoked in the protection of sock
lock, it will be safe, but sctp_lookup_association need to call
rcu_read_lock() and to detect the t->dead to protect it.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: sctp: dynamically enable or disable pf state 2015-12-16T15:56:50+00:00 Zhu Yanjun zyjzyj2000@gmail.com 2015-12-16T05:55:04+00:00 566178f853c1aa57be9c16007c7cca07df5d51b6 As we all know, the value of pf_retrans >= max_retrans_path can disable pf state. The variables of pf_retrans and max_retrans_path can be changed by the userspace application. Sometimes the user expects to disable pf state while the 2 variables are changed to enable pf state. So it is necessary to introduce a new variable to disable pf state. According to the suggestions from Vlad Yasevich, extra1 and extra2 are removed. The initialization of pf_enable is added. Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: Zhu Yanjun <zyjzyj2000@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
As we all know, the value of pf_retrans >= max_retrans_path can
disable pf state. The variables of pf_retrans and max_retrans_path
can be changed by the userspace application.

Sometimes the user expects to disable pf state while the 2
variables are changed to enable pf state. So it is necessary to
introduce a new variable to disable pf state.

According to the suggestions from Vlad Yasevich, extra1 and extra2
are removed. The initialization of pf_enable is added.

Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Zhu Yanjun <zyjzyj2000@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sctp: use GFP_KERNEL in sctp_init() 2015-12-16T04:27:45+00:00 Eric Dumazet edumazet@google.com 2015-12-15T23:33:39+00:00 6857a02af5386e9f5d11734363741dbe6b0a6959 modules init functions being called from process context, we better use GFP_KERNEL allocations to increase our chances to get these high-order pages we want for SCTP hash tables. This mostly matters if SCTP module is loaded once memory got fragmented. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
modules init functions being called from process context, we better
use GFP_KERNEL allocations to increase our chances to get these
high-order pages we want for SCTP hash tables.

This mostly matters if SCTP module is loaded once memory got fragmented.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sctp: fix race on protocol/netns initialization 2015-09-11T22:00:02+00:00 Marcelo Ricardo Leitner marcelo.leitner@gmail.com 2015-09-10T20:31:15+00:00 8e2d61e0aed2b7c4ecb35844fe07e0b2b762dee4 Consider sctp module is unloaded and is being requested because an user is creating a sctp socket. During initialization, sctp will add the new protocol type and then initialize pernet subsys: status = sctp_v4_protosw_init(); if (status) goto err_protosw_init; status = sctp_v6_protosw_init(); if (status) goto err_v6_protosw_init; status = register_pernet_subsys(&sctp_net_ops); The problem is that after those calls to sctp_v{4,6}_protosw_init(), it is possible for userspace to create SCTP sockets like if the module is already fully loaded. If that happens, one of the possible effects is that we will have readers for net->sctp.local_addr_list list earlier than expected and sctp_net_init() does not take precautions while dealing with that list, leading to a potential panic but not limited to that, as sctp_sock_init() will copy a bunch of blank/partially initialized values from net->sctp. The race happens like this: CPU 0 | CPU 1 socket() | __sock_create | socket() inet_create | __sock_create list_for_each_entry_rcu( | answer, &inetsw[sock->type], | list) { | inet_create /* no hits */ | if (unlikely(err)) { | ... | request_module() | /* socket creation is blocked | * the module is fully loaded | */ | sctp_init | sctp_v4_protosw_init | inet_register_protosw | list_add_rcu(&p->list, | last_perm); | | list_for_each_entry_rcu( | answer, &inetsw[sock->type], sctp_v6_protosw_init | list) { | /* hit, so assumes protocol | * is already loaded | */ | /* socket creation continues | * before netns is initialized | */ register_pernet_subsys | Simply inverting the initialization order between register_pernet_subsys() and sctp_v4_protosw_init() is not possible because register_pernet_subsys() will create a control sctp socket, so the protocol must be already visible by then. Deferring the socket creation to a work-queue is not good specially because we loose the ability to handle its errors. So, as suggested by Vlad, the fix is to split netns initialization in two moments: defaults and control socket, so that the defaults are already loaded by when we register the protocol, while control socket initialization is kept at the same moment it is today. Fixes: 4db67e808640 ("sctp: Make the address lists per network namespace") Signed-off-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Consider sctp module is unloaded and is being requested because an user
is creating a sctp socket.

During initialization, sctp will add the new protocol type and then
initialize pernet subsys:

        status = sctp_v4_protosw_init();
        if (status)
                goto err_protosw_init;

        status = sctp_v6_protosw_init();
        if (status)
                goto err_v6_protosw_init;

        status = register_pernet_subsys(&sctp_net_ops);

The problem is that after those calls to sctp_v{4,6}_protosw_init(), it
is possible for userspace to create SCTP sockets like if the module is
already fully loaded. If that happens, one of the possible effects is
that we will have readers for net->sctp.local_addr_list list earlier
than expected and sctp_net_init() does not take precautions while
dealing with that list, leading to a potential panic but not limited to
that, as sctp_sock_init() will copy a bunch of blank/partially
initialized values from net->sctp.

The race happens like this:

     CPU 0                           |  CPU 1
  socket()                           |
   __sock_create                     | socket()
    inet_create                      |  __sock_create
     list_for_each_entry_rcu(        |
        answer, &inetsw[sock->type], |
        list) {                      |   inet_create
      /* no hits */                  |
     if (unlikely(err)) {            |
      ...                            |
      request_module()               |
      /* socket creation is blocked  |
       * the module is fully loaded  |
       */                            |
       sctp_init                     |
        sctp_v4_protosw_init         |
         inet_register_protosw       |
          list_add_rcu(&p->list,     |
                       last_perm);   |
                                     |  list_for_each_entry_rcu(
                                     |     answer, &inetsw[sock->type],
        sctp_v6_protosw_init         |     list) {
                                     |     /* hit, so assumes protocol
                                     |      * is already loaded
                                     |      */
                                     |  /* socket creation continues
                                     |   * before netns is initialized
                                     |   */
        register_pernet_subsys       |

Simply inverting the initialization order between
register_pernet_subsys() and sctp_v4_protosw_init() is not possible
because register_pernet_subsys() will create a control sctp socket, so
the protocol must be already visible by then. Deferring the socket
creation to a work-queue is not good specially because we loose the
ability to handle its errors.

So, as suggested by Vlad, the fix is to split netns initialization in
two moments: defaults and control socket, so that the defaults are
already loaded by when we register the protocol, while control socket
initialization is kept at the same moment it is today.

Fixes: 4db67e808640 ("sctp: Make the address lists per network namespace")
Signed-off-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sctp: add routing output fallback 2015-09-03T22:43:05+00:00 Marcelo Ricardo Leitner marcelo.leitner@gmail.com 2015-09-02T19:20:22+00:00 410f03831c0768f2b1850d28ba697b167ddcb89b Commit 0ca50d12fe46 added a restriction that the address must belong to the output interface, so that sctp will use the right interface even when using secondary addresses. But it breaks IPVS setups, on which people is used to attach VIP addresses to loopback interface on real servers. It's preferred to attach to the interface actually in use, but it's a very common setup and that used to work. This patch then saves the first routing good result, even if it would be going out through an interface that doesn't have that address. If no better hit found, it's then used. This effectively restores the original behavior if no better interface could be found. Fixes: 0ca50d12fe46 ("sctp: fix src address selection if using secondary addresses") Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Commit 0ca50d12fe46 added a restriction that the address must belong to
the output interface, so that sctp will use the right interface even
when using secondary addresses.

But it breaks IPVS setups, on which people is used to attach VIP
addresses to loopback interface on real servers. It's preferred to
attach to the interface actually in use, but it's a very common setup
and that used to work.

This patch then saves the first routing good result, even if it would be
going out through an interface that doesn't have that address. If no
better hit found, it's then used. This effectively restores the original
behavior if no better interface could be found.

Fixes: 0ca50d12fe46 ("sctp: fix src address selection if using secondary addresses")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sctp: fix dst leak 2015-09-03T22:43:05+00:00 Marcelo Ricardo Leitner marcelo.leitner@gmail.com 2015-09-02T19:20:21+00:00 d82f0f1fc8a4f214a50c9dfc64e3896f9894afb7 Commit 0ca50d12fe46 failed to release the reference to dst entries that it decided to skip. Fixes: 0ca50d12fe46 ("sctp: fix src address selection if using secondary addresses") Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Commit 0ca50d12fe46 failed to release the reference to dst entries that
it decided to skip.

Fixes: 0ca50d12fe46 ("sctp: fix src address selection if using secondary addresses")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sctp: fix src address selection if using secondary addresses 2015-07-21T07:20:17+00:00 Marcelo Ricardo Leitner marcelo.leitner@gmail.com 2015-07-17T15:34:18+00:00 0ca50d12fe46cdf3c0dc9ec5ca98607a52afdc62 In short, sctp is likely to incorrectly choose src address if socket is bound to secondary addresses. This patch fixes it by adding a new check that checks if such src address belongs to the interface that routing identified as output. This is enough to avoid rp_filter drops on remote peer. Details: Currently, sctp will do a routing attempt without specifying the src address and compare the returned value (preferred source) with the addresses that the socket is bound to. When using secondary addresses, this will not match. Then it will try specifying each of the addresses that the socket is bound to and re-routing, checking if that address is valid as src for that dst. Thing is, this check alone is weak: # ip r l 192.168.100.0/24 dev eth1 proto kernel scope link src 192.168.100.149 192.168.122.0/24 dev eth0 proto kernel scope link src 192.168.122.147 # ip a l 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether 52:54:00:15:18:6a brd ff:ff:ff:ff:ff:ff inet 192.168.122.147/24 brd 192.168.122.255 scope global dynamic eth0 valid_lft 2160sec preferred_lft 2160sec inet 192.168.122.148/24 scope global secondary eth0 valid_lft forever preferred_lft forever inet6 fe80::5054:ff:fe15:186a/64 scope link valid_lft forever preferred_lft forever 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether 52:54:00:b3:91:46 brd ff:ff:ff:ff:ff:ff inet 192.168.100.149/24 brd 192.168.100.255 scope global dynamic eth1 valid_lft 2162sec preferred_lft 2162sec inet 192.168.100.148/24 scope global secondary eth1 valid_lft forever preferred_lft forever inet6 fe80::5054:ff:feb3:9146/64 scope link valid_lft forever preferred_lft forever 4: ens9: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether 52:54:00:05:47:ee brd ff:ff:ff:ff:ff:ff inet6 fe80::5054:ff:fe05:47ee/64 scope link valid_lft forever preferred_lft forever # ip r g 192.168.100.193 from 192.168.122.148 192.168.100.193 from 192.168.122.148 dev eth1 cache Even if you specify an interface: # ip r g 192.168.100.193 from 192.168.122.148 oif eth1 192.168.100.193 from 192.168.122.148 dev eth1 cache Although this would be valid, peers using rp_filter will drop such packets as their src doesn't match the routes for that interface. Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
In short, sctp is likely to incorrectly choose src address if socket is
bound to secondary addresses. This patch fixes it by adding a new check
that checks if such src address belongs to the interface that routing
identified as output.

This is enough to avoid rp_filter drops on remote peer.

Details:

Currently, sctp will do a routing attempt without specifying the src
address and compare the returned value (preferred source) with the
addresses that the socket is bound to. When using secondary addresses,
this will not match.

Then it will try specifying each of the addresses that the socket is
bound to and re-routing, checking if that address is valid as src for
that dst. Thing is, this check alone is weak:

# ip r l
192.168.100.0/24 dev eth1  proto kernel  scope link  src 192.168.100.149
192.168.122.0/24 dev eth0  proto kernel  scope link  src 192.168.122.147

# ip a l
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 52:54:00:15:18:6a brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.147/24 brd 192.168.122.255 scope global dynamic eth0
       valid_lft 2160sec preferred_lft 2160sec
    inet 192.168.122.148/24 scope global secondary eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::5054:ff:fe15:186a/64 scope link
       valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 52:54:00:b3:91:46 brd ff:ff:ff:ff:ff:ff
    inet 192.168.100.149/24 brd 192.168.100.255 scope global dynamic eth1
       valid_lft 2162sec preferred_lft 2162sec
    inet 192.168.100.148/24 scope global secondary eth1
       valid_lft forever preferred_lft forever
    inet6 fe80::5054:ff:feb3:9146/64 scope link
       valid_lft forever preferred_lft forever
4: ens9: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 52:54:00:05:47:ee brd ff:ff:ff:ff:ff:ff
    inet6 fe80::5054:ff:fe05:47ee/64 scope link
       valid_lft forever preferred_lft forever

# ip r g 192.168.100.193 from 192.168.122.148
192.168.100.193 from 192.168.122.148 dev eth1
    cache

Even if you specify an interface:

# ip r g 192.168.100.193 from 192.168.122.148 oif eth1
192.168.100.193 from 192.168.122.148 dev eth1
    cache

Although this would be valid, peers using rp_filter will drop such
packets as their src doesn't match the routes for that interface.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>