Conflicts:
drivers/net/ethernet/mellanox/mlx4/main.c
net/packet/af_packet.c
Both conflicts were cases of simple overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
->auto_asconf_splist is per namespace and mangled by functions like
sctp_setsockopt_auto_asconf() which doesn't guarantee any serialization.
Also, the call to inet_sk_copy_descendant() was backuping
->auto_asconf_list through the copy but was not honoring
->do_auto_asconf, which could lead to list corruption if it was
different between both sockets.
This commit thus fixes the list handling by using ->addr_wq_lock
spinlock to protect the list. A special handling is done upon socket
creation and destruction for that. Error handlig on sctp_init_sock()
will never return an error after having initialized asconf, so
sctp_destroy_sock() can be called without addrq_wq_lock. The lock now
will be take on sctp_close_sock(), before locking the socket, so we
don't do it in inverse order compared to sctp_addr_wq_timeout_handler().
Instead of taking the lock on sctp_sock_migrate() for copying and
restoring the list values, it's preferred to avoid rewritting it by
implementing sctp_copy_descendant().
Issue was found with a test application that kept flipping sysctl
default_auto_asconf on and off, but one could trigger it by issuing
simultaneous setsockopt() calls on multiple sockets or by
creating/destroying sockets fast enough. This is only triggerable
locally.
Fixes: 9f7d653b67 ("sctp: Add Auto-ASCONF support (core).")
Reported-by: Ji Jianwen <jiji@redhat.com>
Suggested-by: Neil Horman <nhorman@tuxdriver.com>
Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, we can ask to authenticate DATA chunks and we can send DATA
chunks on the same packet as COOKIE_ECHO, but if you try to combine
both, the DATA chunk will be sent unauthenticated and peer won't accept
it, leading to a communication failure.
This happens because even though the data was queued after it was
requested to authenticate DATA chunks, it was also queued before we
could know that remote peer can handle authenticating, so
sctp_auth_send_cid() returns false.
The fix is whenever we set up an active key, re-check send queue for
chunks that now should be authenticated. As a result, such packet will
now contain COOKIE_ECHO + AUTH + DATA chunks, in that order.
Reported-by: Liu Wei <weliu@redhat.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of doing the rt6->rt6i_node check whenever we need
to get the route's cookie. Refactor it into rt6_get_cookie().
It is a prep work to handle FLOWI_FLAG_KNOWN_NH and also
percpu rt6_info later.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes the assumptions that the returned rt is always
a RTF_CACHE entry with the rt6i_dst and rt6i_src containing the
destination and source address. The dst and src can be recovered from
the calling site.
We may consider to rename (rt6i_dst, rt6i_src) to
(rt6i_key_dst, rt6i_key_src) later.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
In preparation for changing how struct net is refcounted
on kernel sockets pass the knowledge that we are creating
a kernel socket from sock_create_kern through to sk_alloc.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move the declaration for external variables to sctp.h file avoiding
to repeatedly declare them with extern keyword.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After TIPC doesn't depend on iocb argument in its internal
implementations of sendmsg() and recvmsg() hooks defined in proto
structure, no any user is using iocb argument in them at all now.
Then we can drop the redundant iocb argument completely from kinds of
implementations of both sendmsg() and recvmsg() in the entire
networking stack.
Cc: Christoph Hellwig <hch@lst.de>
Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As part of an effort to move skb->dropcount to skb->cb[] use a common
macro in protocol families using skb->cb[] for ancillary data to
validate available room in skb->cb[].
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/vxlan.c
drivers/vhost/net.c
include/linux/if_vlan.h
net/core/dev.c
The net/core/dev.c conflict was the overlap of one commit marking an
existing function static whilst another was adding a new function.
In the include/linux/if_vlan.h case, the type used for a local
variable was changed in 'net', whereas the function got rewritten
to fix a stacked vlan bug in 'net-next'.
In drivers/vhost/net.c, Al Viro's iov_iter conversions in 'net-next'
overlapped with an endainness fix for VHOST 1.0 in 'net'.
In drivers/net/vxlan.c, vxlan_find_vni() added a 'flags' parameter
in 'net-next' whereas in 'net' there was a bug fix to pass in the
correct network namespace pointer in calls to this function.
Signed-off-by: David S. Miller <davem@davemloft.net>
The kfree() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-By: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When making use of RFC5061, section 4.2.4. for setting the primary IP
address, we're passing a wrong parameter header to param_type2af(),
resulting always in NULL being returned.
At this point, param.p points to a sctp_addip_param struct, containing
a sctp_paramhdr (type = 0xc004, length = var), and crr_id as a correlation
id. Followed by that, as also presented in RFC5061 section 4.2.4., comes
the actual sctp_addr_param, which also contains a sctp_paramhdr, but
this time with the correct type SCTP_PARAM_IPV{4,6}_ADDRESS that
param_type2af() can make use of. Since we already hold a pointer to
addr_param from previous line, just reuse it for param_type2af().
Fixes: d6de309759 ("[SCTP]: Add the handling of "Set Primary IP Address" parameter to INIT")
Signed-off-by: Saran Maruti Ramanara <saran.neti@telus.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When hitting an INIT collision case during the 4WHS with AUTH enabled, as
already described in detail in commit 1be9a950c6 ("net: sctp: inherit
auth_capable on INIT collisions"), it can happen that we occasionally
still remotely trigger the following panic on server side which seems to
have been uncovered after the fix from commit 1be9a950c6 ...
[ 533.876389] BUG: unable to handle kernel paging request at 00000000ffffffff
[ 533.913657] IP: [<ffffffff811ac385>] __kmalloc+0x95/0x230
[ 533.940559] PGD 5030f2067 PUD 0
[ 533.957104] Oops: 0000 [#1] SMP
[ 533.974283] Modules linked in: sctp mlx4_en [...]
[ 534.939704] Call Trace:
[ 534.951833] [<ffffffff81294e30>] ? crypto_init_shash_ops+0x60/0xf0
[ 534.984213] [<ffffffff81294e30>] crypto_init_shash_ops+0x60/0xf0
[ 535.015025] [<ffffffff8128c8ed>] __crypto_alloc_tfm+0x6d/0x170
[ 535.045661] [<ffffffff8128d12c>] crypto_alloc_base+0x4c/0xb0
[ 535.074593] [<ffffffff8160bd42>] ? _raw_spin_lock_bh+0x12/0x50
[ 535.105239] [<ffffffffa0418c11>] sctp_inet_listen+0x161/0x1e0 [sctp]
[ 535.138606] [<ffffffff814e43bd>] SyS_listen+0x9d/0xb0
[ 535.166848] [<ffffffff816149a9>] system_call_fastpath+0x16/0x1b
... or depending on the the application, for example this one:
[ 1370.026490] BUG: unable to handle kernel paging request at 00000000ffffffff
[ 1370.026506] IP: [<ffffffff811ab455>] kmem_cache_alloc+0x75/0x1d0
[ 1370.054568] PGD 633c94067 PUD 0
[ 1370.070446] Oops: 0000 [#1] SMP
[ 1370.085010] Modules linked in: sctp kvm_amd kvm [...]
[ 1370.963431] Call Trace:
[ 1370.974632] [<ffffffff8120f7cf>] ? SyS_epoll_ctl+0x53f/0x960
[ 1371.000863] [<ffffffff8120f7cf>] SyS_epoll_ctl+0x53f/0x960
[ 1371.027154] [<ffffffff812100d3>] ? anon_inode_getfile+0xd3/0x170
[ 1371.054679] [<ffffffff811e3d67>] ? __alloc_fd+0xa7/0x130
[ 1371.080183] [<ffffffff816149a9>] system_call_fastpath+0x16/0x1b
With slab debugging enabled, we can see that the poison has been overwritten:
[ 669.826368] BUG kmalloc-128 (Tainted: G W ): Poison overwritten
[ 669.826385] INFO: 0xffff880228b32e50-0xffff880228b32e50. First byte 0x6a instead of 0x6b
[ 669.826414] INFO: Allocated in sctp_auth_create_key+0x23/0x50 [sctp] age=3 cpu=0 pid=18494
[ 669.826424] __slab_alloc+0x4bf/0x566
[ 669.826433] __kmalloc+0x280/0x310
[ 669.826453] sctp_auth_create_key+0x23/0x50 [sctp]
[ 669.826471] sctp_auth_asoc_create_secret+0xcb/0x1e0 [sctp]
[ 669.826488] sctp_auth_asoc_init_active_key+0x68/0xa0 [sctp]
[ 669.826505] sctp_do_sm+0x29d/0x17c0 [sctp] [...]
[ 669.826629] INFO: Freed in kzfree+0x31/0x40 age=1 cpu=0 pid=18494
[ 669.826635] __slab_free+0x39/0x2a8
[ 669.826643] kfree+0x1d6/0x230
[ 669.826650] kzfree+0x31/0x40
[ 669.826666] sctp_auth_key_put+0x19/0x20 [sctp]
[ 669.826681] sctp_assoc_update+0x1ee/0x2d0 [sctp]
[ 669.826695] sctp_do_sm+0x674/0x17c0 [sctp]
Since this only triggers in some collision-cases with AUTH, the problem at
heart is that sctp_auth_key_put() on asoc->asoc_shared_key is called twice
when having refcnt 1, once directly in sctp_assoc_update() and yet again
from within sctp_auth_asoc_init_active_key() via sctp_assoc_update() on
the already kzfree'd memory, which is also consistent with the observation
of the poison decrease from 0x6b to 0x6a (note: the overwrite is detected
at a later point in time when poison is checked on new allocation).
Reference counting of auth keys revisited:
Shared keys for AUTH chunks are being stored in endpoints and associations
in endpoint_shared_keys list. On endpoint creation, a null key is being
added; on association creation, all endpoint shared keys are being cached
and thus cloned over to the association. struct sctp_shared_key only holds
a pointer to the actual key bytes, that is, struct sctp_auth_bytes which
keeps track of users internally through refcounting. Naturally, on assoc
or enpoint destruction, sctp_shared_key are being destroyed directly and
the reference on sctp_auth_bytes dropped.
User space can add keys to either list via setsockopt(2) through struct
sctp_authkey and by passing that to sctp_auth_set_key() which replaces or
adds a new auth key. There, sctp_auth_create_key() creates a new sctp_auth_bytes
with refcount 1 and in case of replacement drops the reference on the old
sctp_auth_bytes. A key can be set active from user space through setsockopt()
on the id via sctp_auth_set_active_key(), which iterates through either
endpoint_shared_keys and in case of an assoc, invokes (one of various places)
sctp_auth_asoc_init_active_key().
sctp_auth_asoc_init_active_key() computes the actual secret from local's
and peer's random, hmac and shared key parameters and returns a new key
directly as sctp_auth_bytes, that is asoc->asoc_shared_key, plus drops
the reference if there was a previous one. The secret, which where we
eventually double drop the ref comes from sctp_auth_asoc_set_secret() with
intitial refcount of 1, which also stays unchanged eventually in
sctp_assoc_update(). This key is later being used for crypto layer to
set the key for the hash in crypto_hash_setkey() from sctp_auth_calculate_hmac().
To close the loop: asoc->asoc_shared_key is freshly allocated secret
material and independant of the sctp_shared_key management keeping track
of only shared keys in endpoints and assocs. Hence, also commit 4184b2a79a
("net: sctp: fix memory leak in auth key management") is independant of
this bug here since it concerns a different layer (though same structures
being used eventually). asoc->asoc_shared_key is reference dropped correctly
on assoc destruction in sctp_association_free() and when active keys are
being replaced in sctp_auth_asoc_init_active_key(), it always has a refcount
of 1. Hence, it's freed prematurely in sctp_assoc_update(). Simple fix is
to remove that sctp_auth_key_put() from there which fixes these panics.
Fixes: 730fc3d05c ("[SCTP]: Implete SCTP-AUTH parameter processing")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
I.e. one-to-many sockets in SCTP are not required to explicitly
call into connect(2) or sctp_connectx(2) prior to data exchange.
Instead, they can directly invoke sendmsg(2) and the SCTP stack
will automatically trigger connection establishment through 4WHS
via sctp_primitive_ASSOCIATE(). However, this in its current
implementation is racy: INIT is being sent out immediately (as
it cannot be bundled anyway) and the rest of the DATA chunks are
queued up for later xmit when connection is established, meaning
sendmsg(2) will return successfully. This behaviour can result
in an undesired side-effect that the kernel made the application
think the data has already been transmitted, although none of it
has actually left the machine, worst case even after close(2)'ing
the socket.
Instead, when the association from client side has been shut down
e.g. first gracefully through SCTP_EOF and then close(2), the
client could afterwards still receive the server's INIT_ACK due
to a connection with higher latency. This INIT_ACK is then considered
out of the blue and hence responded with ABORT as there was no
alive assoc found anymore. This can be easily reproduced f.e.
with sctp_test application from lksctp. One way to fix this race
is to wait for the handshake to actually complete.
The fix defers waiting after sctp_primitive_ASSOCIATE() and
sctp_primitive_SEND() succeeded, so that DATA chunks cooked up
from sctp_sendmsg() have already been placed into the output
queue through the side-effect interpreter, and therefore can then
be bundeled together with COOKIE_ECHO control chunks.
strace from example application (shortened):
socket(PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP) = 3
sendmsg(3, {msg_name(28)={sa_family=AF_INET, sin_port=htons(8888), sin_addr=inet_addr("192.168.1.115")},
msg_iov(1)=[{"hello", 5}], msg_controllen=0, msg_flags=0}, 0) = 5
sendmsg(3, {msg_name(28)={sa_family=AF_INET, sin_port=htons(8888), sin_addr=inet_addr("192.168.1.115")},
msg_iov(1)=[{"hello", 5}], msg_controllen=0, msg_flags=0}, 0) = 5
sendmsg(3, {msg_name(28)={sa_family=AF_INET, sin_port=htons(8888), sin_addr=inet_addr("192.168.1.115")},
msg_iov(1)=[{"hello", 5}], msg_controllen=0, msg_flags=0}, 0) = 5
sendmsg(3, {msg_name(28)={sa_family=AF_INET, sin_port=htons(8888), sin_addr=inet_addr("192.168.1.115")},
msg_iov(1)=[{"hello", 5}], msg_controllen=0, msg_flags=0}, 0) = 5
sendmsg(3, {msg_name(28)={sa_family=AF_INET, sin_port=htons(8888), sin_addr=inet_addr("192.168.1.115")},
msg_iov(0)=[], msg_controllen=48, {cmsg_len=48, cmsg_level=0x84 /* SOL_??? */, cmsg_type=, ...},
msg_flags=0}, 0) = 0 // graceful shutdown for SOCK_SEQPACKET via SCTP_EOF
close(3) = 0
tcpdump before patch (fooling the application):
22:33:36.306142 IP 192.168.1.114.41462 > 192.168.1.115.8888: sctp (1) [INIT] [init tag: 3879023686] [rwnd: 106496] [OS: 10] [MIS: 65535] [init TSN: 3139201684]
22:33:36.316619 IP 192.168.1.115.8888 > 192.168.1.114.41462: sctp (1) [INIT ACK] [init tag: 3345394793] [rwnd: 106496] [OS: 10] [MIS: 10] [init TSN: 3380109591]
22:33:36.317600 IP 192.168.1.114.41462 > 192.168.1.115.8888: sctp (1) [ABORT]
tcpdump after patch:
14:28:58.884116 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [INIT] [init tag: 438593213] [rwnd: 106496] [OS: 10] [MIS: 65535] [init TSN: 3092969729]
14:28:58.888414 IP 192.168.1.115.8888 > 192.168.1.114.35846: sctp (1) [INIT ACK] [init tag: 381429855] [rwnd: 106496] [OS: 10] [MIS: 10] [init TSN: 2141904492]
14:28:58.888638 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [COOKIE ECHO] , (2) [DATA] (B)(E) [TSN: 3092969729] [...]
14:28:58.893278 IP 192.168.1.115.8888 > 192.168.1.114.35846: sctp (1) [COOKIE ACK] , (2) [SACK] [cum ack 3092969729] [a_rwnd 106491] [#gap acks 0] [#dup tsns 0]
14:28:58.893591 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [DATA] (B)(E) [TSN: 3092969730] [...]
14:28:59.096963 IP 192.168.1.115.8888 > 192.168.1.114.35846: sctp (1) [SACK] [cum ack 3092969730] [a_rwnd 106496] [#gap acks 0] [#dup tsns 0]
14:28:59.097086 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [DATA] (B)(E) [TSN: 3092969731] [...] , (2) [DATA] (B)(E) [TSN: 3092969732] [...]
14:28:59.103218 IP 192.168.1.115.8888 > 192.168.1.114.35846: sctp (1) [SACK] [cum ack 3092969732] [a_rwnd 106486] [#gap acks 0] [#dup tsns 0]
14:28:59.103330 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [SHUTDOWN]
14:28:59.107793 IP 192.168.1.115.8888 > 192.168.1.114.35846: sctp (1) [SHUTDOWN ACK]
14:28:59.107890 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [SHUTDOWN COMPLETE]
Looks like this bug is from the pre-git history museum. ;)
Fixes: 08707d5482df ("lksctp-2_5_31-0_5_1.patch")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce helper macro for_each_cmsghdr as a wrapper of the enumerating
cmsghdr from msghdr, just cleanup.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/amd/xgbe/xgbe-desc.c
drivers/net/ethernet/renesas/sh_eth.c
Overlapping changes in both conflict cases.
Signed-off-by: David S. Miller <davem@davemloft.net>
Note that the code _using_ ->msg_iter at that point will be very
unhappy with anything other than unshifted iovec-backed iov_iter.
We still need to convert users to proper primitives.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
To accomodate for enough headroom for tunnels, use MAX_HEADER instead
of LL_MAX_HEADER. Robert reported that he has hit after roughly 40hrs
of trinity an skb_under_panic() via SCTP output path (see reference).
I couldn't reproduce it from here, but not using MAX_HEADER as elsewhere
in other protocols might be one possible cause for this.
In any case, it looks like accounting on chunks themself seems to look
good as the skb already passed the SCTP output path and did not hit
any skb_over_panic(). Given tunneling was enabled in his .config, the
headroom would have been expanded by MAX_HEADER in this case.
Reported-by: Robert Święcki <robert@swiecki.net>
Reference: https://lkml.org/lkml/2014/12/1/507
Fixes: 594ccc14df ("[SCTP] Replace incorrect use of dev_alloc_skb with alloc_skb in sctp_packet_transmit().")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It's just silly to hold the skb destructor argument around inside
skb->cb[] as we currently do in SCTP.
Nowadays, we're sort of cheating on data accounting in the sense
that due to commit 4c3a5bdae2 ("sctp: Don't charge for data in
sndbuf again when transmitting packet"), we orphan the skb already
in the SCTP output path, i.e. giving back charged data memory, and
use a different destructor only to make sure the sk doesn't vanish
on skb destruction time. Thus, cb[] is still valid here as we
operate within the SCTP layer. (It's generally actually a big
candidate for future rework, imho.)
However, storing the destructor in the cb[] can easily cause issues
should an non sctp_packet_set_owner_w()'ed skb ever escape the SCTP
layer, since cb[] may get overwritten by lower layers and thus can
corrupt the chunk pointer. There are no such issues at present,
but lets keep the chunk in destructor_arg, as this is the actual
purpose for it.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/chelsio/cxgb4vf/sge.c
drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c
sge.c was overlapping two changes, one to use the new
__dev_alloc_page() in net-next, and one to use s->fl_pg_order in net.
ixgbe_phy.c was a set of overlapping whitespace changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
A very minimal and simple user space application allocating an SCTP
socket, setting SCTP_AUTH_KEY setsockopt(2) on it and then closing
the socket again will leak the memory containing the authentication
key from user space:
unreferenced object 0xffff8800837047c0 (size 16):
comm "a.out", pid 2789, jiffies 4296954322 (age 192.258s)
hex dump (first 16 bytes):
01 00 00 00 04 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff816d7e8e>] kmemleak_alloc+0x4e/0xb0
[<ffffffff811c88d8>] __kmalloc+0xe8/0x270
[<ffffffffa0870c23>] sctp_auth_create_key+0x23/0x50 [sctp]
[<ffffffffa08718b1>] sctp_auth_set_key+0xa1/0x140 [sctp]
[<ffffffffa086b383>] sctp_setsockopt+0xd03/0x1180 [sctp]
[<ffffffff815bfd94>] sock_common_setsockopt+0x14/0x20
[<ffffffff815beb61>] SyS_setsockopt+0x71/0xd0
[<ffffffff816e58a9>] system_call_fastpath+0x12/0x17
[<ffffffffffffffff>] 0xffffffffffffffff
This is bad because of two things, we can bring down a machine from
user space when auth_enable=1, but also we would leave security sensitive
keying material in memory without clearing it after use. The issue is
that sctp_auth_create_key() already sets the refcount to 1, but after
allocation sctp_auth_set_key() does an additional refcount on it, and
thus leaving it around when we free the socket.
Fixes: 65b07e5d0d ("[SCTP]: API updates to suport SCTP-AUTH extensions.")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
An SCTP server doing ASCONF will panic on malformed INIT ping-of-death
in the form of:
------------ INIT[PARAM: SET_PRIMARY_IP] ------------>
While the INIT chunk parameter verification dissects through many things
in order to detect malformed input, it misses to actually check parameters
inside of parameters. E.g. RFC5061, section 4.2.4 proposes a 'set primary
IP address' parameter in ASCONF, which has as a subparameter an address
parameter.
So an attacker may send a parameter type other than SCTP_PARAM_IPV4_ADDRESS
or SCTP_PARAM_IPV6_ADDRESS, param_type2af() will subsequently return 0
and thus sctp_get_af_specific() returns NULL, too, which we then happily
dereference unconditionally through af->from_addr_param().
The trace for the log:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000078
IP: [<ffffffffa01e9c62>] sctp_process_init+0x492/0x990 [sctp]
PGD 0
Oops: 0000 [#1] SMP
[...]
Pid: 0, comm: swapper Not tainted 2.6.32-504.el6.x86_64 #1 Bochs Bochs
RIP: 0010:[<ffffffffa01e9c62>] [<ffffffffa01e9c62>] sctp_process_init+0x492/0x990 [sctp]
[...]
Call Trace:
<IRQ>
[<ffffffffa01f2add>] ? sctp_bind_addr_copy+0x5d/0xe0 [sctp]
[<ffffffffa01e1fcb>] sctp_sf_do_5_1B_init+0x21b/0x340 [sctp]
[<ffffffffa01e3751>] sctp_do_sm+0x71/0x1210 [sctp]
[<ffffffffa01e5c09>] ? sctp_endpoint_lookup_assoc+0xc9/0xf0 [sctp]
[<ffffffffa01e61f6>] sctp_endpoint_bh_rcv+0x116/0x230 [sctp]
[<ffffffffa01ee986>] sctp_inq_push+0x56/0x80 [sctp]
[<ffffffffa01fcc42>] sctp_rcv+0x982/0xa10 [sctp]
[<ffffffffa01d5123>] ? ipt_local_in_hook+0x23/0x28 [iptable_filter]
[<ffffffff8148bdc9>] ? nf_iterate+0x69/0xb0
[<ffffffff81496d10>] ? ip_local_deliver_finish+0x0/0x2d0
[<ffffffff8148bf86>] ? nf_hook_slow+0x76/0x120
[<ffffffff81496d10>] ? ip_local_deliver_finish+0x0/0x2d0
[...]
A minimal way to address this is to check for NULL as we do on all
other such occasions where we know sctp_get_af_specific() could
possibly return with NULL.
Fixes: d6de309759 ("[SCTP]: Add the handling of "Set Primary IP Address" parameter to INIT")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Alternative to RPS/RFS is to use hardware support for multiple
queues.
Then split a set of million of sockets into worker threads, each
one using epoll() to manage events on its own socket pool.
Ideally, we want one thread per RX/TX queue/cpu, but we have no way to
know after accept() or connect() on which queue/cpu a socket is managed.
We normally use one cpu per RX queue (IRQ smp_affinity being properly
set), so remembering on socket structure which cpu delivered last packet
is enough to solve the problem.
After accept(), connect(), or even file descriptor passing around
processes, applications can use :
int cpu;
socklen_t len = sizeof(cpu);
getsockopt(fd, SOL_SOCKET, SO_INCOMING_CPU, &cpu, &len);
And use this information to put the socket into the right silo
for optimal performance, as all networking stack should run
on the appropriate cpu, without need to send IPI (RPS/RFS).
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This encapsulates all of the skb_copy_datagram_iovec() callers
with call argument signature "skb, offset, msghdr->msg_iov, length".
When we move to iov_iters in the networking, the iov_iter object will
sit in the msghdr.
Having a helper like this means there will be less places to touch
during that transformation.
Based upon descriptions and patch from Al Viro.
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes checkpatch warning:
"WARNING: Prefer seq_puts to seq_printf"
Signed-off-by: Michele Baldessari <michele@acksyn.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It is often quite helpful to be able to know the state of a transport
outside of the application itself (for troubleshooting purposes or for
monitoring purposes). Add it under /proc/net/sctp/remaddr.
Signed-off-by: Michele Baldessari <michele@acksyn.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
1) Include fixes for netrom and dsa (Fabian Frederick and Florian
Fainelli)
2) Fix FIXED_PHY support in stmmac, from Giuseppe CAVALLARO.
3) Several SKB use after free fixes (vxlan, openvswitch, vxlan,
ip_tunnel, fou), from Li ROngQing.
4) fec driver PTP support fixes from Luwei Zhou and Nimrod Andy.
5) Use after free in virtio_net, from Michael S Tsirkin.
6) Fix flow mask handling for megaflows in openvswitch, from Pravin B
Shelar.
7) ISDN gigaset and capi bug fixes from Tilman Schmidt.
8) Fix route leak in ip_send_unicast_reply(), from Vasily Averin.
9) Fix two eBPF JIT bugs on x86, from Alexei Starovoitov.
10) TCP_SKB_CB() reorganization caused a few regressions, fixed by Cong
Wang and Eric Dumazet.
11) Don't overwrite end of SKB when parsing malformed sctp ASCONF
chunks, from Daniel Borkmann.
12) Don't call sock_kfree_s() with NULL pointers, this function also has
the side effect of adjusting the socket memory usage. From Cong Wang.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (90 commits)
bna: fix skb->truesize underestimation
net: dsa: add includes for ethtool and phy_fixed definitions
openvswitch: Set flow-key members.
netrom: use linux/uaccess.h
dsa: Fix conversion from host device to mii bus
tipc: fix bug in bundled buffer reception
ipv6: introduce tcp_v6_iif()
sfc: add support for skb->xmit_more
r8152: return -EBUSY for runtime suspend
ipv4: fix a potential use after free in fou.c
ipv4: fix a potential use after free in ip_tunnel_core.c
hyperv: Add handling of IP header with option field in netvsc_set_hash()
openvswitch: Create right mask with disabled megaflows
vxlan: fix a free after use
openvswitch: fix a use after free
ipv4: dst_entry leak in ip_send_unicast_reply()
ipv4: clean up cookie_v4_check()
ipv4: share tcp_v4_save_options() with cookie_v4_check()
ipv4: call __ip_options_echo() in cookie_v4_check()
atm: simplify lanai.c by using module_pci_driver
...
This scenario is not limited to ASCONF, just taken as one
example triggering the issue. When receiving ASCONF probes
in the form of ...
-------------- INIT[ASCONF; ASCONF_ACK] ------------->
<----------- INIT-ACK[ASCONF; ASCONF_ACK] ------------
-------------------- COOKIE-ECHO -------------------->
<-------------------- COOKIE-ACK ---------------------
---- ASCONF_a; [ASCONF_b; ...; ASCONF_n;] JUNK ------>
[...]
---- ASCONF_m; [ASCONF_o; ...; ASCONF_z;] JUNK ------>
... where ASCONF_a, ASCONF_b, ..., ASCONF_z are good-formed
ASCONFs and have increasing serial numbers, we process such
ASCONF chunk(s) marked with !end_of_packet and !singleton,
since we have not yet reached the SCTP packet end. SCTP does
only do verification on a chunk by chunk basis, as an SCTP
packet is nothing more than just a container of a stream of
chunks which it eats up one by one.
We could run into the case that we receive a packet with a
malformed tail, above marked as trailing JUNK. All previous
chunks are here goodformed, so the stack will eat up all
previous chunks up to this point. In case JUNK does not fit
into a chunk header and there are no more other chunks in
the input queue, or in case JUNK contains a garbage chunk
header, but the encoded chunk length would exceed the skb
tail, or we came here from an entirely different scenario
and the chunk has pdiscard=1 mark (without having had a flush
point), it will happen, that we will excessively queue up
the association's output queue (a correct final chunk may
then turn it into a response flood when flushing the
queue ;)): I ran a simple script with incremental ASCONF
serial numbers and could see the server side consuming
excessive amount of RAM [before/after: up to 2GB and more].
The issue at heart is that the chunk train basically ends
with !end_of_packet and !singleton markers and since commit
2e3216cd54 ("sctp: Follow security requirement of responding
with 1 packet") therefore preventing an output queue flush
point in sctp_do_sm() -> sctp_cmd_interpreter() on the input
chunk (chunk = event_arg) even though local_cork is set,
but its precedence has changed since then. In the normal
case, the last chunk with end_of_packet=1 would trigger the
queue flush to accommodate possible outgoing bundling.
In the input queue, sctp_inq_pop() seems to do the right thing
in terms of discarding invalid chunks. So, above JUNK will
not enter the state machine and instead be released and exit
the sctp_assoc_bh_rcv() chunk processing loop. It's simply
the flush point being missing at loop exit. Adding a try-flush
approach on the output queue might not work as the underlying
infrastructure might be long gone at this point due to the
side-effect interpreter run.
One possibility, albeit a bit of a kludge, would be to defer
invalid chunk freeing into the state machine in order to
possibly trigger packet discards and thus indirectly a queue
flush on error. It would surely be better to discard chunks
as in the current, perhaps better controlled environment, but
going back and forth, it's simply architecturally not possible.
I tried various trailing JUNK attack cases and it seems to
look good now.
Joint work with Vlad Yasevich.
Fixes: 2e3216cd54 ("sctp: Follow security requirement of responding with 1 packet")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When receiving a e.g. semi-good formed connection scan in the
form of ...
-------------- INIT[ASCONF; ASCONF_ACK] ------------->
<----------- INIT-ACK[ASCONF; ASCONF_ACK] ------------
-------------------- COOKIE-ECHO -------------------->
<-------------------- COOKIE-ACK ---------------------
---------------- ASCONF_a; ASCONF_b ----------------->
... where ASCONF_a equals ASCONF_b chunk (at least both serials
need to be equal), we panic an SCTP server!
The problem is that good-formed ASCONF chunks that we reply with
ASCONF_ACK chunks are cached per serial. Thus, when we receive a
same ASCONF chunk twice (e.g. through a lost ASCONF_ACK), we do
not need to process them again on the server side (that was the
idea, also proposed in the RFC). Instead, we know it was cached
and we just resend the cached chunk instead. So far, so good.
Where things get nasty is in SCTP's side effect interpreter, that
is, sctp_cmd_interpreter():
While incoming ASCONF_a (chunk = event_arg) is being marked
!end_of_packet and !singleton, and we have an association context,
we do not flush the outqueue the first time after processing the
ASCONF_ACK singleton chunk via SCTP_CMD_REPLY. Instead, we keep it
queued up, although we set local_cork to 1. Commit 2e3216cd54
changed the precedence, so that as long as we get bundled, incoming
chunks we try possible bundling on outgoing queue as well. Before
this commit, we would just flush the output queue.
Now, while ASCONF_a's ASCONF_ACK sits in the corked outq, we
continue to process the same ASCONF_b chunk from the packet. As
we have cached the previous ASCONF_ACK, we find it, grab it and
do another SCTP_CMD_REPLY command on it. So, effectively, we rip
the chunk->list pointers and requeue the same ASCONF_ACK chunk
another time. Since we process ASCONF_b, it's correctly marked
with end_of_packet and we enforce an uncork, and thus flush, thus
crashing the kernel.
Fix it by testing if the ASCONF_ACK is currently pending and if
that is the case, do not requeue it. When flushing the output
queue we may relink the chunk for preparing an outgoing packet,
but eventually unlink it when it's copied into the skb right
before transmission.
Joint work with Vlad Yasevich.
Fixes: 2e3216cd54 ("sctp: Follow security requirement of responding with 1 packet")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 6f4c618ddb ("SCTP : Add paramters validity check for
ASCONF chunk") added basic verification of ASCONF chunks, however,
it is still possible to remotely crash a server by sending a
special crafted ASCONF chunk, even up to pre 2.6.12 kernels:
skb_over_panic: text:ffffffffa01ea1c3 len:31056 put:30768
head:ffff88011bd81800 data:ffff88011bd81800 tail:0x7950
end:0x440 dev:<NULL>
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:129!
[...]
Call Trace:
<IRQ>
[<ffffffff8144fb1c>] skb_put+0x5c/0x70
[<ffffffffa01ea1c3>] sctp_addto_chunk+0x63/0xd0 [sctp]
[<ffffffffa01eadaf>] sctp_process_asconf+0x1af/0x540 [sctp]
[<ffffffff8152d025>] ? _read_unlock_bh+0x15/0x20
[<ffffffffa01e0038>] sctp_sf_do_asconf+0x168/0x240 [sctp]
[<ffffffffa01e3751>] sctp_do_sm+0x71/0x1210 [sctp]
[<ffffffff8147645d>] ? fib_rules_lookup+0xad/0xf0
[<ffffffffa01e6b22>] ? sctp_cmp_addr_exact+0x32/0x40 [sctp]
[<ffffffffa01e8393>] sctp_assoc_bh_rcv+0xd3/0x180 [sctp]
[<ffffffffa01ee986>] sctp_inq_push+0x56/0x80 [sctp]
[<ffffffffa01fcc42>] sctp_rcv+0x982/0xa10 [sctp]
[<ffffffffa01d5123>] ? ipt_local_in_hook+0x23/0x28 [iptable_filter]
[<ffffffff8148bdc9>] ? nf_iterate+0x69/0xb0
[<ffffffff81496d10>] ? ip_local_deliver_finish+0x0/0x2d0
[<ffffffff8148bf86>] ? nf_hook_slow+0x76/0x120
[<ffffffff81496d10>] ? ip_local_deliver_finish+0x0/0x2d0
[<ffffffff81496ded>] ip_local_deliver_finish+0xdd/0x2d0
[<ffffffff81497078>] ip_local_deliver+0x98/0xa0
[<ffffffff8149653d>] ip_rcv_finish+0x12d/0x440
[<ffffffff81496ac5>] ip_rcv+0x275/0x350
[<ffffffff8145c88b>] __netif_receive_skb+0x4ab/0x750
[<ffffffff81460588>] netif_receive_skb+0x58/0x60
This can be triggered e.g., through a simple scripted nmap
connection scan injecting the chunk after the handshake, for
example, ...
-------------- INIT[ASCONF; ASCONF_ACK] ------------->
<----------- INIT-ACK[ASCONF; ASCONF_ACK] ------------
-------------------- COOKIE-ECHO -------------------->
<-------------------- COOKIE-ACK ---------------------
------------------ ASCONF; UNKNOWN ------------------>
... where ASCONF chunk of length 280 contains 2 parameters ...
1) Add IP address parameter (param length: 16)
2) Add/del IP address parameter (param length: 255)
... followed by an UNKNOWN chunk of e.g. 4 bytes. Here, the
Address Parameter in the ASCONF chunk is even missing, too.
This is just an example and similarly-crafted ASCONF chunks
could be used just as well.
The ASCONF chunk passes through sctp_verify_asconf() as all
parameters passed sanity checks, and after walking, we ended
up successfully at the chunk end boundary, and thus may invoke
sctp_process_asconf(). Parameter walking is done with
WORD_ROUND() to take padding into account.
In sctp_process_asconf()'s TLV processing, we may fail in
sctp_process_asconf_param() e.g., due to removal of the IP
address that is also the source address of the packet containing
the ASCONF chunk, and thus we need to add all TLVs after the
failure to our ASCONF response to remote via helper function
sctp_add_asconf_response(), which basically invokes a
sctp_addto_chunk() adding the error parameters to the given
skb.
When walking to the next parameter this time, we proceed
with ...
length = ntohs(asconf_param->param_hdr.length);
asconf_param = (void *)asconf_param + length;
... instead of the WORD_ROUND()'ed length, thus resulting here
in an off-by-one that leads to reading the follow-up garbage
parameter length of 12336, and thus throwing an skb_over_panic
for the reply when trying to sctp_addto_chunk() next time,
which implicitly calls the skb_put() with that length.
Fix it by using sctp_walk_params() [ which is also used in
INIT parameter processing ] macro in the verification *and*
in ASCONF processing: it will make sure we don't spill over,
that we walk parameters WORD_ROUND()'ed. Moreover, we're being
more defensive and guard against unknown parameter types and
missized addresses.
Joint work with Vlad Yasevich.
Fixes: b896b82be4ae ("[SCTP] ADDIP: Support for processing incoming ASCONF_ACK chunks.")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull percpu updates from Tejun Heo:
"A lot of activities on percpu front. Notable changes are...
- percpu allocator now can take @gfp. If @gfp doesn't contain
GFP_KERNEL, it tries to allocate from what's already available to
the allocator and a work item tries to keep the reserve around
certain level so that these atomic allocations usually succeed.
This will replace the ad-hoc percpu memory pool used by
blk-throttle and also be used by the planned blkcg support for
writeback IOs.
Please note that I noticed a bug in how @gfp is interpreted while
preparing this pull request and applied the fix 6ae833c7fe
("percpu: fix how @gfp is interpreted by the percpu allocator")
just now.
- percpu_ref now uses longs for percpu and global counters instead of
ints. It leads to more sparse packing of the percpu counters on
64bit machines but the overhead should be negligible and this
allows using percpu_ref for refcnting pages and in-memory objects
directly.
- The switching between percpu and single counter modes of a
percpu_ref is made independent of putting the base ref and a
percpu_ref can now optionally be initialized in single or killed
mode. This allows avoiding percpu shutdown latency for cases where
the refcounted objects may be synchronously created and destroyed
in rapid succession with only a fraction of them reaching fully
operational status (SCSI probing does this when combined with
blk-mq support). It's also planned to be used to implement forced
single mode to detect underflow more timely for debugging.
There's a separate branch percpu/for-3.18-consistent-ops which cleans
up the duplicate percpu accessors. That branch causes a number of
conflicts with s390 and other trees. I'll send a separate pull
request w/ resolutions once other branches are merged"
* 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (33 commits)
percpu: fix how @gfp is interpreted by the percpu allocator
blk-mq, percpu_ref: start q->mq_usage_counter in atomic mode
percpu_ref: make INIT_ATOMIC and switch_to_atomic() sticky
percpu_ref: add PERCPU_REF_INIT_* flags
percpu_ref: decouple switching to percpu mode and reinit
percpu_ref: decouple switching to atomic mode and killing
percpu_ref: add PCPU_REF_DEAD
percpu_ref: rename things to prepare for decoupling percpu/atomic mode switch
percpu_ref: replace pcpu_ prefix with percpu_
percpu_ref: minor code and comment updates
percpu_ref: relocate percpu_ref_reinit()
Revert "blk-mq, percpu_ref: implement a kludge for SCSI blk-mq stall during probe"
Revert "percpu: free percpu allocation info for uniprocessor system"
percpu-refcount: make percpu_ref based on longs instead of ints
percpu-refcount: improve WARN messages
percpu: fix locking regression in the failure path of pcpu_alloc()
percpu-refcount: add @gfp to percpu_ref_init()
proportions: add @gfp to init functions
percpu_counter: add @gfp to percpu_counter_init()
percpu_counter: make percpu_counters_lock irq-safe
...
Currently association restarts do not take into consideration the
state of the socket. When a restart happens, the current assocation
simply transitions into established state. This creates a condition
where a remote system, through a the restart procedure, may create a
local association that is no way reachable by user. The conditions
to trigger this are as follows:
1) Remote does not acknoledge some data causing data to remain
outstanding.
2) Local application calls close() on the socket. Since data
is still outstanding, the association is placed in SHUTDOWN_PENDING
state. However, the socket is closed.
3) The remote tries to create a new association, triggering a restart
on the local system. The association moves from SHUTDOWN_PENDING
to ESTABLISHED. At this point, it is no longer reachable by
any socket on the local system.
This patch addresses the above situation by moving the newly ESTABLISHED
association into SHUTDOWN-SENT state and bundling a SHUTDOWN after
the COOKIE-ACK chunk. This way, the restarted associate immidiately
enters the shutdown procedure and forces the termination of the
unreachable association.
Reported-by: David Laight <David.Laight@aculab.com>
Signed-off-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is to receive 0a30288da1 ("blk-mq, percpu_ref: implement a
kludge for SCSI blk-mq stall during probe") which implements
__percpu_ref_kill_expedited() to work around SCSI blk-mq stall. The
commit reverted and patches to implement proper fix will be added.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
net.ipv4.ip_nonlocal_bind sysctl was global to all network
namespaces. This patch allows to set a different value for each
network namespace.
Signed-off-by: Vincent Bernat <vincent@bernat.im>
Signed-off-by: David S. Miller <davem@davemloft.net>
Percpu allocator now supports allocation mask. Add @gfp to
percpu_counter_init() so that !GFP_KERNEL allocation masks can be used
with percpu_counters too.
We could have left percpu_counter_init() alone and added
percpu_counter_init_gfp(); however, the number of users isn't that
high and introducing _gfp variants to all percpu data structures would
be quite ugly, so let's just do the conversion. This is the one with
the most users. Other percpu data structures are a lot easier to
convert.
This patch doesn't make any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: "David S. Miller" <davem@davemloft.net>
Cc: x86@kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
CHECKSUM_UNNECESSARY may be applied to the SCTP CRC so we need to
appropriate account for this by decrementing csum_level. This is
done by calling __skb_dec_checksum_unnecessary.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since SCTP day 1, that is, 19b55a2af145 ("Initial commit") from lksctp
tree, the official <netinet/sctp.h> header carries a copy of enum
sctp_sstat_state that looks like (compared to the current in-kernel
enumeration):
User definition: Kernel definition:
enum sctp_sstat_state { typedef enum {
SCTP_EMPTY = 0, <removed>
SCTP_CLOSED = 1, SCTP_STATE_CLOSED = 0,
SCTP_COOKIE_WAIT = 2, SCTP_STATE_COOKIE_WAIT = 1,
SCTP_COOKIE_ECHOED = 3, SCTP_STATE_COOKIE_ECHOED = 2,
SCTP_ESTABLISHED = 4, SCTP_STATE_ESTABLISHED = 3,
SCTP_SHUTDOWN_PENDING = 5, SCTP_STATE_SHUTDOWN_PENDING = 4,
SCTP_SHUTDOWN_SENT = 6, SCTP_STATE_SHUTDOWN_SENT = 5,
SCTP_SHUTDOWN_RECEIVED = 7, SCTP_STATE_SHUTDOWN_RECEIVED = 6,
SCTP_SHUTDOWN_ACK_SENT = 8, SCTP_STATE_SHUTDOWN_ACK_SENT = 7,
}; } sctp_state_t;
This header was later on also placed into the uapi, so that user space
programs can compile without having <netinet/sctp.h>, but the shipped
with <linux/sctp.h> instead.
While RFC6458 under 8.2.1.Association Status (SCTP_STATUS) says that
sstat_state can range from SCTP_CLOSED to SCTP_SHUTDOWN_ACK_SENT, we
nevertheless have a what it appears to be dummy SCTP_EMPTY state from
the very early days.
While it seems to do just nothing, commit 0b8f9e25b0 ("sctp: remove
completely unsed EMPTY state") did the right thing and removed this dead
code. That however, causes an off-by-one when the user asks the SCTP
stack via SCTP_STATUS API and checks for the current socket state thus
yielding possibly undefined behaviour in applications as they expect
the kernel to tell the right thing.
The enumeration had to be changed however as based on the current socket
state, we access a function pointer lookup-table through this. Therefore,
I think the best way to deal with this is just to add a helper function
sctp_assoc_to_state() to encapsulate the off-by-one quirk.
Reported-by: Tristan Su <sooqing@gmail.com>
Fixes: 0b8f9e25b0 ("sctp: remove completely unsed EMPTY state")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In SCTP, selection of active (T.ACT) and retransmission (T.RET)
transports is being done whenever transport control operations
(UP, DOWN, PF, ...) are engaged through sctp_assoc_control_transport().
Commits 4c47af4d5e ("net: sctp: rework multihoming retransmission
path selection to rfc4960") and a7288c4dd5 ("net: sctp: improve
sctp_select_active_and_retran_path selection") have both improved
it towards a more fine-grained and optimal path selection.
Currently, the selection algorithm for T.ACT and T.RET is as follows:
1) Elect the two most recently used ACTIVE transports T1, T2 for
T.ACT, T.RET, where T.ACT<-T1 and T1 is most recently used
2) In case primary path T.PRI not in {T1, T2} but ACTIVE, set
T.ACT<-T.PRI and T.RET<-T1
3) If only T1 is ACTIVE from the set, set T.ACT<-T1 and T.RET<-T1
4) If none is ACTIVE, set T.ACT<-best(T.PRI, T.RET, T3) where
T3 is the most recently used (if avail) in PF, set T.RET<-T.PRI
Prior to above commits, 4) was simply a camp on T.ACT<-T.PRI and
T.RET<-T.PRI, ignoring possible paths in PF. Camping on T.PRI is
still slightly suboptimal as it can lead to the following scenario:
Setup:
<A> <B>
T1: p1p1 (10.0.10.10) <==> .'`) <==> p1p1 (10.0.10.12) <= T.PRI
T2: p1p2 (10.0.10.20) <==> (_ . ) <==> p1p2 (10.0.10.22)
net.sctp.rto_min = 1000
net.sctp.path_max_retrans = 2
net.sctp.pf_retrans = 0
net.sctp.hb_interval = 1000
T.PRI is permanently down, T2 is put briefly into PF state (e.g. due to
link flapping). Here, the first time transmission is sent over PF path
T2 as it's the only non-INACTIVE path, but the retransmitted data-chunks
are sent over the INACTIVE path T1 (T.PRI), which is not good.
After the patch, it's choosing better transports in both cases by
modifying step 4):
4) If none is ACTIVE, set T.ACT_new<-best(T.ACT_old, T3) where T3 is
the most recently used (if avail) in PF, set T.RET<-T.ACT_new
This will still select a best possible path in PF if available (which
can also include T.PRI/T.RET), and set both T.ACT/T.RET to it.
In case sctp_assoc_control_transport() *just* put T.ACT_old into INACTIVE
as it transitioned from ACTIVE->PF->INACTIVE and stays in INACTIVE just
for a very short while before going back ACTIVE, it will guarantee that
this path will be reselected for T.ACT/T.RET since T3 (PF) is not
available.
Previously, this was not possible, as we would only select between T.PRI
and T.RET, and a possible T3 would be NULL due to the fact that we have
just transitioned T3 in sctp_assoc_control_transport() from PF->INACTIVE
and would select a suboptimal path when T.PRI/T.RET have worse properties.
In the case that T.ACT_old permanently went to INACTIVE during this
transition and there's no PF path available, plus T.PRI and T.RET are
INACTIVE as well, we would now camp on T.ACT_old, but if everything is
being INACTIVE there's really not much we can do except hoping for a
successful HB to bring one of the transports back up again and, thus
cause a new selection through sctp_assoc_control_transport().
Now both tests work fine:
Case 1:
1. T1 S(ACTIVE) T.ACT
T2 S(ACTIVE) T.RET
2. T1 S(ACTIVE) T.ACT, T.RET
T2 S(PF)
3. T1 S(ACTIVE) T.ACT, T.RET
T2 S(INACTIVE)
5. T1 S(PF) T.ACT, T.RET
T2 S(INACTIVE)
[ 5.1 T1 S(INACTIVE) T.ACT, T.RET
T2 S(INACTIVE) ]
6. T1 S(ACTIVE) T.ACT, T.RET
T2 S(INACTIVE)
7. T1 S(ACTIVE) T.ACT
T2 S(ACTIVE) T.RET
Case 2:
1. T1 S(ACTIVE) T.ACT
T2 S(ACTIVE) T.RET
2. T1 S(PF)
T2 S(ACTIVE) T.ACT, T.RET
3. T1 S(INACTIVE)
T2 S(ACTIVE) T.ACT, T.RET
5. T1 S(INACTIVE)
T2 S(PF) T.ACT, T.RET
[ 5.1 T1 S(INACTIVE)
T2 S(INACTIVE) T.ACT, T.RET ]
6. T1 S(INACTIVE)
T2 S(ACTIVE) T.ACT, T.RET
7. T1 S(ACTIVE) T.ACT
T2 S(ACTIVE) T.RET
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When both transports are the same, we don't have to go down that
road only to realize that we will return the very same transport.
We are guaranteed that curr is always non-NULL. Therefore, just
short-circuit this special case.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since the transport has always been in state SCTP_UNCONFIRMED, it
therefore wasn't active before and hasn't been used before, and it
always has been, so it is unnecessary to bug the user with a
notification.
Reported-by: Deepak Khandelwal <khandelwal.deepak.1987@gmail.com>
Suggested-by: Vlad Yasevich <vyasevich@gmail.com>
Suggested-by: Michael Tuexen <tuexen@fh-muenster.de>
Suggested-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Zhu Yanjun <Yanjun.Zhu@windriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/Makefile
net/ipv6/sysctl_net_ipv6.c
Two ipv6_table_template[] additions overlap, so the index
of the ipv6_table[x] assignments needed to be adjusted.
In the drivers/net/Makefile case, we've gotten rid of the
garbage whereby we had to list every single USB networking
driver in the top-level Makefile, there is just one
"USB_NETWORKING" that guards everything.
Signed-off-by: David S. Miller <davem@davemloft.net>
When dealing with ICMPv[46] Error Message, function icmp_socket_deliver()
and icmpv6_notify() do some valid checks on packet's length, but then some
protocols check packet's length redaudantly. So remove those duplicated
statements, and increase counter ICMP_MIB_INERRORS/ICMP6_MIB_INERRORS in
function icmp_socket_deliver() and icmpv6_notify() respectively.
In addition, add missed counter in udp6/udplite6 when socket is NULL.
Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Alexander Sverdlin