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  1. 22 1月, 2016 3 次提交
    • I
      libceph: fix ceph_msg_revoke() · 67645d76
      由 Ilya Dryomov 提交于 
      There are a number of problems with revoking a "was sending" message:

(1) We never make any attempt to revoke data - only kvecs contibute to
con->out_skip.  However, once the header (envelope) is written to the
socket, our peer learns data_len and sets itself to expect at least
data_len bytes to follow front or front+middle.  If ceph_msg_revoke()
is called while the messenger is sending message's data portion,
anything we send after that call is counted by the OSD towards the now
revoked message's data portion.  The effects vary, the most common one
is the eventual hang - higher layers get stuck waiting for the reply to
the message that was sent out after ceph_msg_revoke() returned and
treated by the OSD as a bunch of data bytes.  This is what Matt ran
into.

(2) Flat out zeroing con->out_kvec_bytes worth of bytes to handle kvecs
is wrong.  If ceph_msg_revoke() is called before the tag is sent out or
while the messenger is sending the header, we will get a connection
reset, either due to a bad tag (0 is not a valid tag) or a bad header
CRC, which kind of defeats the purpose of revoke.  Currently the kernel
client refuses to work with header CRCs disabled, but that will likely
change in the future, making this even worse.

(3) con->out_skip is not reset on connection reset, leading to one or
more spurious connection resets if we happen to get a real one between
con->out_skip is set in ceph_msg_revoke() and before it's cleared in
write_partial_skip().

Fixing (1) and (3) is trivial.  The idea behind fixing (2) is to never
zero the tag or the header, i.e. send out tag+header regardless of when
ceph_msg_revoke() is called.  That way the header is always correct, no
unnecessary resets are induced and revoke stands ready for disabled
CRCs.  Since ceph_msg_revoke() rips out con->out_msg, introduce a new
"message out temp" and copy the header into it before sending.

Cc: stable@vger.kernel.org # 4.0+
Reported-by: NMatt Conner <matt.conner@keepertech.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Tested-by: NMatt Conner <matt.conner@keepertech.com>
Reviewed-by: NSage Weil <sage@redhat.com>
      67645d76
    • G
      libceph: use list_for_each_entry_safe · 10bcee14
      由 Geliang Tang 提交于 
      Use list_for_each_entry_safe() instead of list_for_each_safe() to
simplify the code.
Signed-off-by: NGeliang Tang <geliangtang@163.com>
[idryomov@gmail.com: nuke call to list_splice_init() as well]
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
      10bcee14
    • G
      libceph: use list_next_entry instead of list_entry_next · 17ddc49b
      由 Geliang Tang 提交于 
      list_next_entry has been defined in list.h, so I replace list_entry_next
with it.
Signed-off-by: NGeliang Tang <geliangtang@163.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
      17ddc49b
  3. 07 1月, 2016 2 次提交
    • Y
      tcp: fix zero cwnd in tcp_cwnd_reduction · 8b8a321f
      由 Yuchung Cheng 提交于 
      Patch 3759824d ("tcp: PRR uses CRB mode by default and SS mode
conditionally") introduced a bug that cwnd may become 0 when both
inflight and sndcnt are 0 (cwnd = inflight + sndcnt). This may lead
to a div-by-zero if the connection starts another cwnd reduction
phase by setting tp->prior_cwnd to the current cwnd (0) in
tcp_init_cwnd_reduction().

To prevent this we skip PRR operation when nothing is acked or
sacked. Then cwnd must be positive in all cases as long as ssthresh
is positive:

1) The proportional reduction mode
   inflight > ssthresh > 0

2) The reduction bound mode
  a) inflight == ssthresh > 0

  b) inflight < ssthresh
     sndcnt > 0 since newly_acked_sacked > 0 and inflight < ssthresh

Therefore in all cases inflight and sndcnt can not both be 0.
We check invalid tp->prior_cwnd to avoid potential div0 bugs.

In reality this bug is triggered only with a sequence of less common
events.  For example, the connection is terminating an ECN-triggered
cwnd reduction with an inflight 0, then it receives reordered/old
ACKs or DSACKs from prior transmission (which acks nothing). Or the
connection is in fast recovery stage that marks everything lost,
but fails to retransmit due to local issues, then receives data
packets from other end which acks nothing.

Fixes: 3759824d ("tcp: PRR uses CRB mode by default and SS mode conditionally")
Reported-by: NOleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      8b8a321f
    • F
      net: possible use after free in dst_release · 07a5d384
      由 Francesco Ruggeri 提交于 
      dst_release should not access dst->flags after decrementing
__refcnt to 0. The dst_entry may be in dst_busy_list and
dst_gc_task may dst_destroy it before dst_release gets a chance
to access dst->flags.

Fixes: d69bbf88 ("net: fix a race in dst_release()")
Fixes: 27b75c95 ("net: avoid RCU for NOCACHE dst")
Signed-off-by: NFrancesco Ruggeri <fruggeri@arista.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      07a5d384
  5. 06 1月, 2016 2 次提交
  7. 05 1月, 2016 2 次提交
    • R
      af_unix: Fix splice-bind deadlock · c845acb3
      由 Rainer Weikusat 提交于 
      On 2015/11/06, Dmitry Vyukov reported a deadlock involving the splice
system call and AF_UNIX sockets,

http://lists.openwall.net/netdev/2015/11/06/24

The situation was analyzed as

(a while ago) A: socketpair()
B: splice() from a pipe to /mnt/regular_file
	does sb_start_write() on /mnt
C: try to freeze /mnt
	wait for B to finish with /mnt
A: bind() try to bind our socket to /mnt/new_socket_name
	lock our socket, see it not bound yet
	decide that it needs to create something in /mnt
	try to do sb_start_write() on /mnt, block (it's
	waiting for C).
D: splice() from the same pipe to our socket
	lock the pipe, see that socket is connected
	try to lock the socket, block waiting for A
B:	get around to actually feeding a chunk from
	pipe to file, try to lock the pipe.  Deadlock.

on 2015/11/10 by Al Viro,

http://lists.openwall.net/netdev/2015/11/10/4

The patch fixes this by removing the kern_path_create related code from
unix_mknod and executing it as part of unix_bind prior acquiring the
readlock of the socket in question. This means that A (as used above)
will sb_start_write on /mnt before it acquires the readlock, hence, it
won't indirectly block B which first did a sb_start_write and then
waited for a thread trying to acquire the readlock. Consequently, A
being blocked by C waiting for B won't cause a deadlock anymore
(effectively, both A and B acquire two locks in opposite order in the
situation described above).

Dmitry Vyukov(<dvyukov@google.com>) tested the original patch.
Signed-off-by: NRainer Weikusat <rweikusat@mobileactivedefense.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c845acb3
    • D
      net: Propagate lookup failure in l3mdev_get_saddr to caller · b5bdacf3
      由 David Ahern 提交于 
      Commands run in a vrf context are not failing as expected on a route lookup:
    root@kenny:~# ip ro ls table vrf-red
    unreachable default

    root@kenny:~# ping -I vrf-red -c1 -w1 10.100.1.254
    ping: Warning: source address might be selected on device other than vrf-red.
    PING 10.100.1.254 (10.100.1.254) from 0.0.0.0 vrf-red: 56(84) bytes of data.

    --- 10.100.1.254 ping statistics ---
    2 packets transmitted, 0 received, 100% packet loss, time 999ms

Since the vrf table does not have a route for 10.100.1.254 the ping
should have failed. The saddr lookup causes a full VRF table lookup.
Propogating a lookup failure to the user allows the command to fail as
expected:

    root@kenny:~# ping -I vrf-red -c1 -w1 10.100.1.254
    connect: No route to host
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b5bdacf3
  9. 31 12月, 2015 2 次提交
    • X
      sctp: sctp should release assoc when sctp_make_abort_user return NULL in sctp_close · 068d8bd3
      由 Xin Long 提交于 
      In sctp_close, sctp_make_abort_user may return NULL because of memory
allocation failure. If this happens, it will bypass any state change
and never free the assoc. The assoc has no chance to be freed and it
will be kept in memory with the state it had even after the socket is
closed by sctp_close().

So if sctp_make_abort_user fails to allocate memory, we should abort
the asoc via sctp_primitive_ABORT as well. Just like the annotation in
sctp_sf_cookie_wait_prm_abort and sctp_sf_do_9_1_prm_abort said,
"Even if we can't send the ABORT due to low memory delete the TCB.
This is a departure from our typical NOMEM handling".

But then the chunk is NULL (low memory) and the SCTP_CMD_REPLY cmd would
dereference the chunk pointer, and system crash. So we should add
SCTP_CMD_REPLY cmd only when the chunk is not NULL, just like other
places where it adds SCTP_CMD_REPLY cmd.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      068d8bd3
    • N
      net, socket, socket_wq: fix missing initialization of flags · 574aab1e
      由 Nicolai Stange 提交于 
      Commit ceb5d58b ("net: fix sock_wake_async() rcu protection") from
the current 4.4 release cycle introduced a new flags member in
struct socket_wq and moved SOCKWQ_ASYNC_NOSPACE and SOCKWQ_ASYNC_WAITDATA
from struct socket's flags member into that new place.

Unfortunately, the new flags field is never initialized properly, at least
not for the struct socket_wq instance created in sock_alloc_inode().

One particular issue I encountered because of this is that my GNU Emacs
failed to draw anything on my desktop -- i.e. what I got is a transparent
window, including the title bar. Bisection lead to the commit mentioned
above and further investigation by means of strace told me that Emacs
is indeed speaking to my Xorg through an O_ASYNC AF_UNIX socket. This is
reproducible 100% of times and the fact that properly initializing the
struct socket_wq ->flags fixes the issue leads me to the conclusion that
somehow SOCKWQ_ASYNC_WAITDATA got set in the uninitialized ->flags,
preventing my Emacs from receiving any SIGIO's due to data becoming
available and it got stuck.

Make sock_alloc_inode() set the newly created struct socket_wq's ->flags
member to zero.

Fixes: ceb5d58b ("net: fix sock_wake_async() rcu protection")
Signed-off-by: NNicolai Stange <nicstange@gmail.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      574aab1e
  11. 30 12月, 2015 1 次提交
    • J
      openvswitch: Fix template leak in error cases. · 90c7afc9
      由 Joe Stringer 提交于 
      Commit 5b48bb8506c5 ("openvswitch: Fix helper reference leak") fixed a
reference leak on helper objects, but inadvertently introduced a leak on
the ct template.

Previously, ct_info.ct->general.use was initialized to 0 by
nf_ct_tmpl_alloc() and only incremented when ovs_ct_copy_action()
returned successful. If an error occurred while adding the helper or
adding the action to the actions buffer, the __ovs_ct_free_action()
cleanup would use nf_ct_put() to free the entry; However, this relies on
atomic_dec_and_test(ct_info.ct->general.use). This reference must be
incremented first, or nf_ct_put() will never free it.

Fix the issue by acquiring a reference to the template immediately after
allocation.

Fixes: cae3a262 ("openvswitch: Allow attaching helpers to ct action")
Fixes: 5b48bb8506c5 ("openvswitch: Fix helper reference leak")
Signed-off-by: NJoe Stringer <joe@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      90c7afc9
  13. 28 12月, 2015 2 次提交
  15. 24 12月, 2015 1 次提交
  17. 23 12月, 2015 3 次提交
  19. 19 12月, 2015 2 次提交
  21. 18 12月, 2015 5 次提交
  23. 17 12月, 2015 1 次提交
  25. 16 12月, 2015 4 次提交
  27. 15 12月, 2015 10 次提交