linux-stable.git/net, branch v4.9.2

SUNRPC: fix refcounting problems with auth_gss messages.

2017-01-09T07:32:25+00:00

commit 1cded9d2974fe4fe339fc0ccd6638b80d465ab2c upstream.

There are two problems with refcounting of auth_gss messages.

First, the reference on the pipe->pipe list (taken by a call
to rpc_queue_upcall()) is not counted.  It seems to be
assumed that a message in pipe->pipe will always also be in
pipe->in_downcall, where it is correctly reference counted.

However there is no guaranty of this.  I have a report of a
NULL dereferences in rpc_pipe_read() which suggests a msg
that has been freed is still on the pipe->pipe list.

One way I imagine this might happen is:
- message is queued for uid=U and auth->service=S1
- rpc.gssd reads this message and starts processing.
  This removes the message from pipe->pipe
- message is queued for uid=U and auth->service=S2
- rpc.gssd replies to the first message. gss_pipe_downcall()
  calls __gss_find_upcall(pipe, U, NULL) and it finds the
  *second* message, as new messages are placed at the head
  of ->in_downcall, and the service type is not checked.
- This second message is removed from ->in_downcall and freed
  by gss_release_msg() (even though it is still on pipe->pipe)
- rpc.gssd tries to read another message, and dereferences a pointer
  to this message that has just been freed.

I fix this by incrementing the reference count before calling
rpc_queue_upcall(), and decrementing it if that fails, or normally in
gss_pipe_destroy_msg().

It seems strange that the reply doesn't target the message more
precisely, but I don't know all the details.  In any case, I think the
reference counting irregularity became a measureable bug when the
extra arg was added to __gss_find_upcall(), hence the Fixes: line
below.

The second problem is that if rpc_queue_upcall() fails, the new
message is not freed. gss_alloc_msg() set the ->count to 1,
gss_add_msg() increments this to 2, gss_unhash_msg() decrements to 1,
then the pointer is discarded so the memory never gets freed.

Fixes: 9130b8dbc6ac ("SUNRPC: allow for upcalls for same uid but different gss service")
Link: https://bugzilla.opensuse.org/show_bug.cgi?id=1011250
Signed-off-by: NeilBrown 
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman

libceph: verify authorize reply on connect

2017-01-09T07:32:24+00:00

commit 5c056fdc5b474329037f2aa18401bd73033e0ce0 upstream.

After sending an authorizer (ceph_x_authorize_a + ceph_x_authorize_b),
the client gets back a ceph_x_authorize_reply, which it is supposed to
verify to ensure the authenticity and protect against replay attacks.
The code for doing this is there (ceph_x_verify_authorizer_reply(),
ceph_auth_verify_authorizer_reply() + plumbing), but it is never
invoked by the the messenger.

AFAICT this goes back to 2009, when ceph authentication protocols
support was added to the kernel client in 4e7a5dcd1bba ("ceph:
negotiate authentication protocol; implement AUTH_NONE protocol").

The second param of ceph_connection_operations::verify_authorizer_reply
is unused all the way down.  Pass 0 to facilitate backporting, and kill
it in the next commit.

Signed-off-by: Ilya Dryomov 
Reviewed-by: Sage Weil 
Signed-off-by: Greg Kroah-Hartman

vsock/virtio: fix src/dst cid format

2017-01-09T07:32:23+00:00

commit f83f12d660d11718d3eed9d979ee03e83aa55544 upstream.

These fields are 64 bit, using le32_to_cpu and friends
on these will not do the right thing.
Fix this up.

Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Greg Kroah-Hartman

cfg80211/mac80211: fix BSS leaks when abandoning assoc attempts

2017-01-09T07:32:17+00:00

commit e6f462df9acd2a3295e5d34eb29e2823220cf129 upstream.

When mac80211 abandons an association attempt, it may free
all the data structures, but inform cfg80211 and userspace
about it only by sending the deauth frame it received, in
which case cfg80211 has no link to the BSS struct that was
used and will not cfg80211_unhold_bss() it.

Fix this by providing a way to inform cfg80211 of this with
the BSS entry passed, so that it can clean up properly, and
use this ability in the appropriate places in mac80211.

This isn't ideal: some code is more or less duplicated and
tracing is missing. However, it's a fairly small change and
it's thus easier to backport - cleanups can come later.

Signed-off-by: Johannes Berg 
Signed-off-by: Greg Kroah-Hartman

can: raw: raw_setsockopt: limit number of can_filter that can be set

2016-12-07T09:45:57+00:00

This patch adds a check to limit the number of can_filters that can be
set via setsockopt on CAN_RAW sockets. Otherwise allocations > MAX_ORDER
are not prevented resulting in a warning.

Reference: https://lkml.org/lkml/2016/12/2/230

Reported-by: Andrey Konovalov 
Tested-by: Andrey Konovalov 
Cc: linux-stable 
Signed-off-by: Marc Kleine-Budde

tcp: warn on bogus MSS and try to amend it

2016-12-06T16:01:19+00:00

There have been some reports lately about TCP connection stalls caused
by NIC drivers that aren't setting gso_size on aggregated packets on rx
path. This causes TCP to assume that the MSS is actually the size of the
aggregated packet, which is invalid.

Although the proper fix is to be done at each driver, it's often hard
and cumbersome for one to debug, come to such root cause and report/fix
it.

This patch amends this situation in two ways. First, it adds a warning
on when this situation occurs, so it gives a hint to those trying to
debug this. It also limit the maximum probed MSS to the adverised MSS,
as it should never be any higher than that.

The result is that the connection may not have the best performance ever
but it shouldn't stall, and the admin will have a hint on what to look
for.

Tested with virtio by forcing gso_size to 0.

v2: updated msg per David's suggestion
v3: use skb_iif to find the interface and also log its name, per Eric
    Dumazet's suggestion. As the skb may be backlogged and the interface
    gone by then, we need to check if the number still has a meaning.
v4: use helper tcp_gro_dev_warn() and avoid pr_warn_once inside __once, per
    David's suggestion

Cc: Jonathan Maxwell 
Signed-off-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

netlink: Do not schedule work from sk_destruct

2016-12-06T00:43:42+00:00

It is wrong to schedule a work from sk_destruct using the socket
as the memory reserve because the socket will be freed immediately
after the return from sk_destruct.

Instead we should do the deferral prior to sk_free.

This patch does just that.

Fixes: 707693c8a498 ("netlink: Call cb->done from a worker thread")
Signed-off-by: Herbert Xu 
Tested-by: Andrey Konovalov 
Signed-off-by: David S. Miller

net: caif: remove ineffective check

2016-12-05T19:48:48+00:00

The check of the return value of sock_register() is ineffective.
"if(!err)" seems to be a typo. It is better to propagate the error code
to the callers of caif_sktinit_module(). This patch removes the check
statment and directly returns the result of sock_register().

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188751
Signed-off-by: Pan Bian 
Signed-off-by: David S. Miller

net: ping: check minimum size on ICMP header length

2016-12-05T18:35:38+00:00

Prior to commit c0371da6047a ("put iov_iter into msghdr") in v3.19, there
was no check that the iovec contained enough bytes for an ICMP header,
and the read loop would walk across neighboring stack contents. Since the
iov_iter conversion, bad arguments are noticed, but the returned error is
EFAULT. Returning EINVAL is a clearer error and also solves the problem
prior to v3.19.

This was found using trinity with KASAN on v3.18:

BUG: KASAN: stack-out-of-bounds in memcpy_fromiovec+0x60/0x114 at addr ffffffc071077da0
Read of size 8 by task trinity-c2/9623
page:ffffffbe034b9a08 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x0()
page dumped because: kasan: bad access detected
CPU: 0 PID: 9623 Comm: trinity-c2 Tainted: G    BU         3.18.0-dirty #15
Hardware name: Google Tegra210 Smaug Rev 1,3+ (DT)
Call trace:
[] dump_backtrace+0x0/0x1ac arch/arm64/kernel/traps.c:90
[] show_stack+0x10/0x1c arch/arm64/kernel/traps.c:171
[<     inline     >] __dump_stack lib/dump_stack.c:15
[] dump_stack+0x7c/0xd0 lib/dump_stack.c:50
[<     inline     >] print_address_description mm/kasan/report.c:147
[<     inline     >] kasan_report_error mm/kasan/report.c:236
[] kasan_report+0x380/0x4b8 mm/kasan/report.c:259
[<     inline     >] check_memory_region mm/kasan/kasan.c:264
[] __asan_load8+0x20/0x70 mm/kasan/kasan.c:507
[] memcpy_fromiovec+0x5c/0x114 lib/iovec.c:15
[<     inline     >] memcpy_from_msg include/linux/skbuff.h:2667
[] ping_common_sendmsg+0x50/0x108 net/ipv4/ping.c:674
[] ping_v4_sendmsg+0xd8/0x698 net/ipv4/ping.c:714
[] inet_sendmsg+0xe0/0x12c net/ipv4/af_inet.c:749
[<     inline     >] __sock_sendmsg_nosec net/socket.c:624
[<     inline     >] __sock_sendmsg net/socket.c:632
[] sock_sendmsg+0x124/0x164 net/socket.c:643
[<     inline     >] SYSC_sendto net/socket.c:1797
[] SyS_sendto+0x178/0x1d8 net/socket.c:1761

CVE-2016-8399

Reported-by: Qidan He 
Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook 
Signed-off-by: David S. Miller

net: bridge: set error code on failure

2016-12-05T18:26:22+00:00

Function br_sysfs_addbr() does not set error code when the call
kobject_create_and_add() returns a NULL pointer. It may be better to
return "-ENOMEM" when kobject_create_and_add() fails.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188781

Signed-off-by: Pan Bian 
Acked-by: Stephen Hemminger 
Signed-off-by: David S. Miller