linux-stable.git/net/sched, branch linux-3.10.y

net sched actions: decrement module reference count after table flush.

2017-06-07T22:47:04+00:00

commit edb9d1bff4bbe19b8ae0e71b1f38732591a9eeb2 upstream.

When tc actions are loaded as a module and no actions have been installed,
flushing them would result in actions removed from the memory, but modules
reference count not being decremented, so that the modules would not be
unloaded.

Following is example with GACT action:

% sudo modprobe act_gact
% lsmod
Module                  Size  Used by
act_gact               16384  0
%
% sudo tc actions ls action gact
%
% sudo tc actions flush action gact
% lsmod
Module                  Size  Used by
act_gact               16384  1
% sudo tc actions flush action gact
% lsmod
Module                  Size  Used by
act_gact               16384  2
% sudo rmmod act_gact
rmmod: ERROR: Module act_gact is in use
....

After the fix:
% lsmod
Module                  Size  Used by
act_gact               16384  0
%
% sudo tc actions add action pass index 1
% sudo tc actions add action pass index 2
% sudo tc actions add action pass index 3
% lsmod
Module                  Size  Used by
act_gact               16384  3
%
% sudo tc actions flush action gact
% lsmod
Module                  Size  Used by
act_gact               16384  0
%
% sudo tc actions flush action gact
% lsmod
Module                  Size  Used by
act_gact               16384  0
% sudo rmmod act_gact
% lsmod
Module                  Size  Used by
%

Fixes: f97017cdefef ("net-sched: Fix actions flushing")
Signed-off-by: Roman Mashak 
Signed-off-by: Jamal Hadi Salim 
Acked-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Willy Tarreau

net/sched: em_meta: Fix 'meta vlan' to correctly recognize zero VID frames

2017-06-07T22:47:00+00:00

commit d65f2fa680d6f91438461df54c83a331b3a631c9 upstream.

META_COLLECTOR int_vlan_tag() assumes that if the accel tag (vlan_tci)
is zero, then no vlan accel tag is present.

This is incorrect for zero VID vlan accel packets, making the following
match fail:
  tc filter add ... basic match 'meta(vlan mask 0xfff eq 0)' ...

Apparently 'int_vlan_tag' was implemented prior VLAN_TAG_PRESENT was
introduced in 05423b2 "vlan: allow null VLAN ID to be used"
(and at time introduced, the 'vlan_tx_tag_get' call in em_meta was not
 adapted).

Fix, testing skb_vlan_tag_present instead of testing skb_vlan_tag_get's
value.

Fixes: 05423b2413 ("vlan: allow null VLAN ID to be used")
Fixes: 1a31f2042e ("netsched: Allow meta match on vlan tag on receive")

Signed-off-by: Shmulik Ladkani 
Cc: Eric Dumazet 
Cc: Stephen Hemminger 
Signed-off-by: David S. Miller 
Signed-off-by: Willy Tarreau

net, sched: fix soft lockup in tc_classify

2017-06-07T22:46:53+00:00

commit 628185cfddf1dfb701c4efe2cfd72cf5b09f5702 upstream.

Shahar reported a soft lockup in tc_classify(), where we run into an
endless loop when walking the classifier chain due to tp->next == tp
which is a state we should never run into. The issue only seems to
trigger under load in the tc control path.

What happens is that in tc_ctl_tfilter(), thread A allocates a new
tp, initializes it, sets tp_created to 1, and calls into tp->ops->change()
with it. In that classifier callback we had to unlock/lock the rtnl
mutex and returned with -EAGAIN. One reason why we need to drop there
is, for example, that we need to request an action module to be loaded.

This happens via tcf_exts_validate() -> tcf_action_init/_1() meaning
after we loaded and found the requested action, we need to redo the
whole request so we don't race against others. While we had to unlock
rtnl in that time, thread B's request was processed next on that CPU.
Thread B added a new tp instance successfully to the classifier chain.
When thread A returned grabbing the rtnl mutex again, propagating -EAGAIN
and destroying its tp instance which never got linked, we goto replay
and redo A's request.

This time when walking the classifier chain in tc_ctl_tfilter() for
checking for existing tp instances we had a priority match and found
the tp instance that was created and linked by thread B. Now calling
again into tp->ops->change() with that tp was successful and returned
without error.

tp_created was never cleared in the second round, thus kernel thinks
that we need to link it into the classifier chain (once again). tp and
*back point to the same object due to the match we had earlier on. Thus
for thread B's already public tp, we reset tp->next to tp itself and
link it into the chain, which eventually causes the mentioned endless
loop in tc_classify() once a packet hits the data path.

Fix is to clear tp_created at the beginning of each request, also when
we replay it. On the paths that can cause -EAGAIN we already destroy
the original tp instance we had and on replay we really need to start
from scratch. It seems that this issue was first introduced in commit
12186be7d2e1 ("net_cls: fix unconfigured struct tcf_proto keeps chaining
and avoid kernel panic when we use cls_cgroup").

Fixes: 12186be7d2e1 ("net_cls: fix unconfigured struct tcf_proto keeps chaining and avoid kernel panic when we use cls_cgroup")
Reported-by: Shahar Klein 
Signed-off-by: Daniel Borkmann 
Cc: Cong Wang 
Acked-by: Eric Dumazet 
Tested-by: Shahar Klein 
Signed-off-by: David S. Miller 
Signed-off-by: Willy Tarreau

net_sched: invoke ->attach() after setting dev->qdisc

2015-06-22T23:55:51+00:00

[ Upstream commit 86e363dc3b50bfd50a1f315934583fbda673ab8d ]

For mq qdisc, we add per tx queue qdisc to root qdisc
for display purpose, however, that happens too early,
before the new dev->qdisc is finally set, this causes
q->list points to an old root qdisc which is going to be
freed right before assigning with a new one.

Fix this by moving ->attach() after setting dev->qdisc.

For the record, this fixes the following crash:

 ------------[ cut here ]------------
 WARNING: CPU: 1 PID: 975 at lib/list_debug.c:59 __list_del_entry+0x5a/0x98()
 list_del corruption. prev->next should be ffff8800d1998ae8, but was 6b6b6b6b6b6b6b6b
 CPU: 1 PID: 975 Comm: tc Not tainted 4.1.0-rc4+ #1019
 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  0000000000000009 ffff8800d73fb928 ffffffff81a44e7f 0000000047574756
  ffff8800d73fb978 ffff8800d73fb968 ffffffff810790da ffff8800cfc4cd20
  ffffffff814e725b ffff8800d1998ae8 ffffffff82381250 0000000000000000
 Call Trace:
  [] dump_stack+0x4c/0x65
  [] warn_slowpath_common+0x9c/0xb6
  [] ? __list_del_entry+0x5a/0x98
  [] warn_slowpath_fmt+0x46/0x48
  [] ? dev_graft_qdisc+0x5e/0x6a
  [] __list_del_entry+0x5a/0x98
  [] list_del+0xe/0x2d
  [] qdisc_list_del+0x1e/0x20
  [] qdisc_destroy+0x30/0xd6
  [] qdisc_graft+0x11d/0x243
  [] tc_get_qdisc+0x1a6/0x1d4
  [] ? mark_lock+0x2e/0x226
  [] rtnetlink_rcv_msg+0x181/0x194
  [] ? rtnl_lock+0x17/0x19
  [] ? rtnl_lock+0x17/0x19
  [] ? __rtnl_unlock+0x17/0x17
  [] netlink_rcv_skb+0x4d/0x93
  [] rtnetlink_rcv+0x26/0x2d
  [] netlink_unicast+0xcb/0x150
  [] ? might_fault+0x59/0xa9
  [] netlink_sendmsg+0x4fa/0x51c
  [] sock_sendmsg_nosec+0x12/0x1d
  [] sock_sendmsg+0x29/0x2e
  [] ___sys_sendmsg+0x1b4/0x23a
  [] ? native_sched_clock+0x35/0x37
  [] ? sched_clock_local+0x12/0x72
  [] ? sched_clock_cpu+0x9e/0xb7
  [] ? current_kernel_time+0xe/0x32
  [] ? lock_release_holdtime.part.29+0x71/0x7f
  [] ? read_seqcount_begin.constprop.27+0x5f/0x76
  [] ? trace_hardirqs_on_caller+0x17d/0x199
  [] ? __fget_light+0x50/0x78
  [] __sys_sendmsg+0x42/0x60
  [] SyS_sendmsg+0x12/0x1c
  [] system_call_fastpath+0x12/0x6f
 ---[ end trace ef29d3fb28e97ae7 ]---

For long term, we probably need to clean up the qdisc_graft() code
in case it hides other bugs like this.

Fixes: 95dc19299f74 ("pkt_sched: give visibility to mq slave qdiscs")
Cc: Jamal Hadi Salim 
Signed-off-by: Cong Wang 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ematch: Fix auto-loading of ematch modules.

2015-03-18T12:22:27+00:00

[ Upstream commit 34eea79e2664b314cab6a30fc582fdfa7a1bb1df ]

In tcf_em_validate(), after calling request_module() to load the
kind-specific module, set em->ops to NULL before returning -EAGAIN, so
that module_put() is not called again by tcf_em_tree_destroy().

Signed-off-by: Ignacy Gawędzki 
Acked-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: Use netlink_ns_capable to verify the permisions of netlink messages

2014-06-26T19:12:37+00:00

[ Upstream commit 90f62cf30a78721641e08737bda787552428061e ]

It is possible by passing a netlink socket to a more privileged
executable and then to fool that executable into writing to the socket
data that happens to be valid netlink message to do something that
privileged executable did not intend to do.

To keep this from happening replace bare capable and ns_capable calls
with netlink_capable, netlink_net_calls and netlink_ns_capable calls.
Which act the same as the previous calls except they verify that the
opener of the socket had the desired permissions as well.

Reported-by: Andy Lutomirski 
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net_sched: htb: fix a typo in htb_change_class()

2013-10-13T23:08:29+00:00

[ Upstream commit f3ad857e3da1abaea780dc892b592cd86c541c52 ]

Fix a typo added in commit 56b765b79 ("htb: improved accuracy at high
rates")

cbuffer should not be a copy of buffer.

Signed-off-by: Vimalkumar 
Signed-off-by: Eric Dumazet 
Cc: Jesper Dangaard Brouer 
Cc: Jiri Pirko 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net_sched: restore "linklayer atm" handling

2013-09-14T13:54:55+00:00

[ Upstream commit 8a8e3d84b1719a56f9151909e80ea6ebc5b8e318 ]

commit 56b765b79 ("htb: improved accuracy at high rates")
broke the "linklayer atm" handling.

 tc class add ... htb rate X ceil Y linklayer atm

The linklayer setting is implemented by modifying the rate table
which is send to the kernel.  No direct parameter were
transferred to the kernel indicating the linklayer setting.

The commit 56b765b79 ("htb: improved accuracy at high rates")
removed the use of the rate table system.

To keep compatible with older iproute2 utils, this patch detects
the linklayer by parsing the rate table.  It also supports future
versions of iproute2 to send this linklayer parameter to the
kernel directly. This is done by using the __reserved field in
struct tc_ratespec, to convey the choosen linklayer option, but
only using the lower 4 bits of this field.

Linklayer detection is limited to speeds below 100Mbit/s, because
at high rates the rtab is gets too inaccurate, so bad that
several fields contain the same values, this resembling the ATM
detect.  Fields even start to contain "0" time to send, e.g. at
1000Mbit/s sending a 96 bytes packet cost "0", thus the rtab have
been more broken than we first realized.

Signed-off-by: Jesper Dangaard Brouer 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

htb: fix sign extension bug

2013-09-14T13:54:54+00:00

[ Upstream commit cbd375567f7e4811b1c721f75ec519828ac6583f ]

When userspace passes a large priority value
the assignment of the unsigned value hopt->prio
to  signed int cl->prio causes cl->prio to become negative and the
comparison is with TC_HTB_NUMPRIO is always false.

The result is that HTB crashes by referencing outside
the array when processing packets. With this patch the large value
wraps around like other values outside the normal range.

See: https://bugzilla.kernel.org/show_bug.cgi?id=60669

Signed-off-by: Stephen Hemminger 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net_sched: info leak in atm_tc_dump_class()

2013-08-12T01:35:26+00:00

[ Upstream commit 8cb3b9c3642c0263d48f31d525bcee7170eedc20 ]

The "pvc" struct has a hole after pvc.sap_family which is not cleared.

Signed-off-by: Dan Carpenter 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman