linux-stable.git/net, branch v3.2.79

mld, igmp: Fix reserved tailroom calculation

2016-04-01T00:54:37+00:00

commit 1837b2e2bcd23137766555a63867e649c0b637f0 upstream.

The current reserved_tailroom calculation fails to take hlen and tlen into
account.

skb:
[__hlen__|__data____________|__tlen___|__extra__]
^                                               ^
head                                            skb_end_offset

In this representation, hlen + data + tlen is the size passed to alloc_skb.
"extra" is the extra space made available in __alloc_skb because of
rounding up by kmalloc. We can reorder the representation like so:

[__hlen__|__data____________|__extra__|__tlen___]
^                                               ^
head                                            skb_end_offset

The maximum space available for ip headers and payload without
fragmentation is min(mtu, data + extra). Therefore,
reserved_tailroom
= data + extra + tlen - min(mtu, data + extra)
= skb_end_offset - hlen - min(mtu, skb_end_offset - hlen - tlen)
= skb_tailroom - min(mtu, skb_tailroom - tlen) ; after skb_reserve(hlen)

Compare the second line to the current expression:
reserved_tailroom = skb_end_offset - min(mtu, skb_end_offset)
and we can see that hlen and tlen are not taken into account.

The min() in the third line can be expanded into:
if mtu < skb_tailroom - tlen:
	reserved_tailroom = skb_tailroom - mtu
else:
	reserved_tailroom = tlen

Depending on hlen, tlen, mtu and the number of multicast address records,
the current code may output skbs that have less tailroom than
dev->needed_tailroom or it may output more skbs than needed because not all
space available is used.

Fixes: 4c672e4b ("ipv6: mld: fix add_grhead skb_over_panic for devs with large MTUs")
Signed-off-by: Benjamin Poirier 
Acked-by: Hannes Frederic Sowa 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

sunrpc/cache: fix off-by-one in qword_get()

2016-04-01T00:54:34+00:00

commit b7052cd7bcf3c1478796e93e3dff2b44c9e82943 upstream.

The qword_get() function NUL-terminates its output buffer.  If the input
string is in hex format \xXXXX... and the same length as the output
buffer, there is an off-by-one:

  int qword_get(char **bpp, char *dest, int bufsize)
  {
      ...
      while (len < bufsize) {
          ...
          *dest++ = (h << 4) | l;
          len++;
      }
      ...
      *dest = '\0';
      return len;
  }

This patch ensures the NUL terminator doesn't fall outside the output
buffer.

Signed-off-by: Stefan Hajnoczi 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Ben Hutchings

mac80211: minstrel_ht: set default tx aggregation timeout to 0

2016-04-01T00:54:34+00:00

commit 7a36b930e6ed4702c866dc74a5ad07318a57c688 upstream.

The value 5000 was put here with the addition of the timeout field to
ieee80211_start_tx_ba_session. It was originally added in mac80211 to
save resources for drivers like iwlwifi, which only supports a limited
number of concurrent aggregation sessions.

Since iwlwifi does not use minstrel_ht and other drivers don't need
this, 0 is a better default - especially since there have been
recent reports of aggregation setup related issues reproduced with
ath9k. This should improve stability without causing any adverse
effects.

Acked-by: Avery Pennarun 
Signed-off-by: Felix Fietkau 
Signed-off-by: Johannes Berg 
Signed-off-by: Ben Hutchings

af_unix: Guard against other == sk in unix_dgram_sendmsg

2016-04-01T00:54:33+00:00

commit a5527dda344fff0514b7989ef7a755729769daa1 upstream.

The unix_dgram_sendmsg routine use the following test

if (unlikely(unix_peer(other) != sk && unix_recvq_full(other))) {

to determine if sk and other are in an n:1 association (either
established via connect or by using sendto to send messages to an
unrelated socket identified by address). This isn't correct as the
specified address could have been bound to the sending socket itself or
because this socket could have been connected to itself by the time of
the unix_peer_get but disconnected before the unix_state_lock(other). In
both cases, the if-block would be entered despite other == sk which
might either block the sender unintentionally or lead to trying to unlock
the same spin lock twice for a non-blocking send. Add a other != sk
check to guard against this.

Fixes: 7d267278a9ec ("unix: avoid use-after-free in ep_remove_wait_queue")
Reported-By: Philipp Hahn 
Signed-off-by: Rainer Weikusat 
Tested-by: Philipp Hahn 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

af_unix: Don't set err in unix_stream_read_generic unless there was an error

2016-04-01T00:54:33+00:00

commit 1b92ee3d03af6643df395300ba7748f19ecdb0c5 upstream.

The present unix_stream_read_generic contains various code sequences of
the form

err = -EDISASTER;
if ()
	goto out;

This has the unfortunate side effect of possibly causing the error code
to bleed through to the final

out:
	return copied ? : err;

and then to be wrongly returned if no data was copied because the caller
didn't supply a data buffer, as demonstrated by the program available at

http://pad.lv/1540731

Change it such that err is only set if an error condition was detected.

Fixes: 3822b5c2fc62 ("af_unix: Revert 'lock_interruptible' in stream receive code")
Reported-by: Joseph Salisbury 
Signed-off-by: Rainer Weikusat 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

mac80211: fix use of uninitialised values in RX aggregation

2016-04-01T00:54:31+00:00

commit f39ea2690bd61efec97622c48323f40ed6e16317 upstream.

Use kzalloc instead of kmalloc for struct tid_ampdu_rx to
initialize the "removed" field (all others are initialized
manually). That fixes:

UBSAN: Undefined behaviour in net/mac80211/rx.c:932:29
load of value 2 is not a valid value for type '_Bool'
CPU: 3 PID: 1134 Comm: kworker/u16:7 Not tainted 4.5.0-rc1+ #265
Workqueue: phy0 rt2x00usb_work_rxdone
 0000000000000004 ffff880254a7ba50 ffffffff8181d866 0000000000000007
 ffff880254a7ba78 ffff880254a7ba68 ffffffff8188422d ffffffff8379b500
 ffff880254a7bab8 ffffffff81884747 0000000000000202 0000000348620032
Call Trace:
 [] dump_stack+0x45/0x5f
 [] ubsan_epilogue+0xd/0x40
 [] __ubsan_handle_load_invalid_value+0x67/0x70
 [] ieee80211_sta_reorder_release.isra.16+0x5ed/0x730
 [] ieee80211_prepare_and_rx_handle+0xd04/0x1c00
 [] __ieee80211_rx_handle_packet+0x1f3/0x750
 [] ieee80211_rx_napi+0x447/0x990

While at it, convert to use sizeof(*tid_agg_rx) instead.

Fixes: 788211d81bfdf ("mac80211: fix RX A-MPDU session reorder timer deletion")
Signed-off-by: Chris Bainbridge 
[reword commit message, use sizeof(*tid_agg_rx)]
Signed-off-by: Johannes Berg 
Signed-off-by: Ben Hutchings

cfg80211/wext: fix message ordering

2016-04-01T00:54:31+00:00

commit cb150b9d23be6ee7f3a0fff29784f1c5b5ac514d upstream.

Since cfg80211 frequently takes actions from its netdev notifier
call, wireless extensions messages could still be ordered badly
since the wext netdev notifier, since wext is built into the
kernel, runs before the cfg80211 netdev notifier. For example,
the following can happen:

5: wlan1:  mtu 1500 qdisc mq state DOWN group default
    link/ether 02:00:00:00:01:00 brd ff:ff:ff:ff:ff:ff
5: wlan1: 
    link/ether

when setting the interface down causes the wext message.

To also fix this, export the wireless_nlevent_flush() function
and also call it from the cfg80211 notifier.

Signed-off-by: Johannes Berg 
[bwh: Backported to 3.2:
 - Add default case in cfg80211_netdev_notifier_call() which bypasses
   the added wireless_nlevent_flush() (added upstream by commit
   6784c7db8d43 "cfg80211: change return value of notifier function")
 - Adjust context]
Signed-off-by: Ben Hutchings

wext: fix message delay/ordering

2016-04-01T00:54:31+00:00

commit 8bf862739a7786ae72409220914df960a0aa80d8 upstream.

Beniamino reported that he was getting an RTM_NEWLINK message for a
given interface, after the RTM_DELLINK for it. It turns out that the
message is a wireless extensions message, which was sent because the
interface had been connected and disconnection while it was deleted
caused a wext message.

For its netlink messages, wext uses RTM_NEWLINK, but the message is
without all the regular rtnetlink attributes, so "ip monitor link"
prints just rudimentary information:

5: wlan1:  mtu 1500 qdisc mq state DOWN group default
    link/ether 02:00:00:00:01:00 brd ff:ff:ff:ff:ff:ff
Deleted 5: wlan1:  mtu 1500 qdisc noop state DOWN group default
    link/ether 02:00:00:00:01:00 brd ff:ff:ff:ff:ff:ff
5: wlan1: 
    link/ether
(from my hwsim reproduction)

This can cause userspace to get confused since it doesn't expect an
RTM_NEWLINK message after RTM_DELLINK.

The reason for this is that wext schedules a worker to send out the
messages, and the scheduling delay can cause the messages to get out
to userspace in different order.

To fix this, have wext register a netdevice notifier and flush out
any pending messages when netdevice state changes. This fixes any
ordering whenever the original message wasn't sent by a notifier
itself.

Reported-by: Beniamino Galvani 
Signed-off-by: Johannes Berg 
Signed-off-by: Ben Hutchings

unix: correctly track in-flight fds in sending process user_struct

2016-02-27T14:28:49+00:00

commit 415e3d3e90ce9e18727e8843ae343eda5a58fad6 upstream.

The commit referenced in the Fixes tag incorrectly accounted the number
of in-flight fds over a unix domain socket to the original opener
of the file-descriptor. This allows another process to arbitrary
deplete the original file-openers resource limit for the maximum of
open files. Instead the sending processes and its struct cred should
be credited.

To do so, we add a reference counted struct user_struct pointer to the
scm_fp_list and use it to account for the number of inflight unix fds.

Fixes: 712f4aad406bb1 ("unix: properly account for FDs passed over unix sockets")
Reported-by: David Herrmann 
Cc: David Herrmann 
Cc: Willy Tarreau 
Cc: Linus Torvalds 
Suggested-by: Linus Torvalds 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

unix: properly account for FDs passed over unix sockets

2016-02-27T14:28:49+00:00

commit 712f4aad406bb1ed67f3f98d04c044191f0ff593 upstream.

It is possible for a process to allocate and accumulate far more FDs than
the process' limit by sending them over a unix socket then closing them
to keep the process' fd count low.

This change addresses this problem by keeping track of the number of FDs
in flight per user and preventing non-privileged processes from having
more FDs in flight than their configured FD limit.

Reported-by: socketpair@gmail.com
Reported-by: Tetsuo Handa 
Mitigates: CVE-2013-4312 (Linux 2.0+)
Suggested-by: Linus Torvalds 
Acked-by: Hannes Frederic Sowa 
Signed-off-by: Willy Tarreau 
Signed-off-by: David S. Miller 
[carnil: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings