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  1. 05 Oct, 2014 34 commits
  3. 17 Sep, 2014 6 commits
    • Greg Kroah-Hartman's avatar
      Linux 3.14.19 · af92ba8f
      Greg Kroah-Hartman authored
      af92ba8f
    • David Howells's avatar
      KEYS: Fix termination condition in assoc array garbage collection · 1143261f
      David Howells authored 
      commit 95389b08 upstream.

This fixes CVE-2014-3631.

It is possible for an associative array to end up with a shortcut node at the
root of the tree if there are more than fan-out leaves in the tree, but they
all crowd into the same slot in the lowest level (ie. they all have the same
first nibble of their index keys).

When assoc_array_gc() returns back up the tree after scanning some leaves, it
can fall off of the root and crash because it assumes that the back pointer
from a shortcut (after label ascend_old_tree) must point to a normal node -
which isn't true of a shortcut node at the root.

Should we find we're ascending rootwards over a shortcut, we should check to
see if the backpointer is zero - and if it is, we have completed the scan.

This particular bug cannot occur if the root node is not a shortcut - ie. if
you have fewer than 17 keys in a keyring or if you have at least two keys that
sit into separate slots (eg. a keyring and a non keyring).

This can be reproduced by:

	ring=`keyctl newring bar @s`
	for ((i=1; i<=18; i++)); do last_key=`keyctl newring foo$i $ring`; done
	keyctl timeout $last_key 2

Doing this:

	echo 3 >/proc/sys/kernel/keys/gc_delay

first will speed things up.

If we do fall off of the top of the tree, we get the following oops:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
IP: [<ffffffff8136cea7>] assoc_array_gc+0x2f7/0x540
PGD dae15067 PUD cfc24067 PMD 0
Oops: 0000 [#1] SMP
Modules linked in: xt_nat xt_mark nf_conntrack_netbios_ns nf_conntrack_broadcast ip6t_rpfilter ip6t_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_ni
CPU: 0 PID: 26011 Comm: kworker/0:1 Not tainted 3.14.9-200.fc20.x86_64 #1
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Workqueue: events key_garbage_collector
task: ffff8800918bd580 ti: ffff8800aac14000 task.ti: ffff8800aac14000
RIP: 0010:[<ffffffff8136cea7>] [<ffffffff8136cea7>] assoc_array_gc+0x2f7/0x540
RSP: 0018:ffff8800aac15d40  EFLAGS: 00010206
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8800aaecacc0
RDX: ffff8800daecf440 RSI: 0000000000000001 RDI: ffff8800aadc2bc0
RBP: ffff8800aac15da8 R08: 0000000000000001 R09: 0000000000000003
R10: ffffffff8136ccc7 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000070 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88011fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000018 CR3: 00000000db10d000 CR4: 00000000000006f0
Stack:
 ffff8800aac15d50 0000000000000011 ffff8800aac15db8 ffffffff812e2a70
 ffff880091a00600 0000000000000000 ffff8800aadc2bc3 00000000cd42c987
 ffff88003702df20 ffff88003702dfa0 0000000053b65c09 ffff8800aac15fd8
Call Trace:
 [<ffffffff812e2a70>] ? keyring_detect_cycle_iterator+0x30/0x30
 [<ffffffff812e3e75>] keyring_gc+0x75/0x80
 [<ffffffff812e1424>] key_garbage_collector+0x154/0x3c0
 [<ffffffff810a67b6>] process_one_work+0x176/0x430
 [<ffffffff810a744b>] worker_thread+0x11b/0x3a0
 [<ffffffff810a7330>] ? rescuer_thread+0x3b0/0x3b0
 [<ffffffff810ae1a8>] kthread+0xd8/0xf0
 [<ffffffff810ae0d0>] ? insert_kthread_work+0x40/0x40
 [<ffffffff816ffb7c>] ret_from_fork+0x7c/0xb0
 [<ffffffff810ae0d0>] ? insert_kthread_work+0x40/0x40
Code: 08 4c 8b 22 0f 84 bf 00 00 00 41 83 c7 01 49 83 e4 fc 41 83 ff 0f 4c 89 65 c0 0f 8f 5a fe ff ff 48 8b 45 c0 4d 63 cf 49 83 c1 02 <4e> 8b 34 c8 4d 85 f6 0f 84 be 00 00 00 41 f6 c6 01 0f 84 92
RIP  [<ffffffff8136cea7>] assoc_array_gc+0x2f7/0x540
 RSP <ffff8800aac15d40>
CR2: 0000000000000018
---[ end trace 1129028a088c0cbd ]---
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarDon Zickus <dzickus@redhat.com>
Signed-off-by: default avatarJames Morris <james.l.morris@oracle.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1143261f
    • David Howells's avatar
      KEYS: Fix use-after-free in assoc_array_gc() · ed35863a
      David Howells authored 
      commit 27419604 upstream.

An edit script should be considered inaccessible by a function once it has
called assoc_array_apply_edit() or assoc_array_cancel_edit().

However, assoc_array_gc() is accessing the edit script just after the
gc_complete: label.
Reported-by: default avatarAndreea-Cristina Bernat <bernat.ada@gmail.com>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Reviewed-by: default avatarAndreea-Cristina Bernat <bernat.ada@gmail.com>
cc: shemming@brocade.com
cc: paulmck@linux.vnet.ibm.com
Signed-off-by: default avatarJames Morris <james.l.morris@oracle.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ed35863a
    • Sage Weil's avatar
      libceph: gracefully handle large reply messages from the mon · d6e22ca5
      Sage Weil authored 
      commit 73c3d481 upstream.

We preallocate a few of the message types we get back from the mon.  If we
get a larger message than we are expecting, fall back to trying to allocate
a new one instead of blindly using the one we have.
Signed-off-by: default avatarSage Weil <sage@redhat.com>
Reviewed-by: default avatarIlya Dryomov <ilya.dryomov@inktank.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d6e22ca5
    • Linus Torvalds's avatar
      vfs: fix bad hashing of dentries · a8be8af1
      Linus Torvalds authored 
      commit 99d263d4 upstream.

Josef Bacik found a performance regression between 3.2 and 3.10 and
narrowed it down to commit bfcfaa77 ("vfs: use 'unsigned long'
accesses for dcache name comparison and hashing"). He reports:

 "The test case is essentially

      for (i = 0; i < 1000000; i++)
              mkdir("a$i");

  On xfs on a fio card this goes at about 20k dir/sec with 3.2, and 12k
  dir/sec with 3.10.  This is because we spend waaaaay more time in
  __d_lookup on 3.10 than in 3.2.

  The new hashing function for strings is suboptimal for <
  sizeof(unsigned long) string names (and hell even > sizeof(unsigned
  long) string names that I've tested).  I broke out the old hashing
  function and the new one into a userspace helper to get real numbers
  and this is what I'm getting:

      Old hash table had 1000000 entries, 0 dupes, 0 max dupes
      New hash table had 12628 entries, 987372 dupes, 900 max dupes
      We had 11400 buckets with a p50 of 30 dupes, p90 of 240 dupes, p99 of 567 dupes for the new hash

  My test does the hash, and then does the d_hash into a integer pointer
  array the same size as the dentry hash table on my system, and then
  just increments the value at the address we got to see how many
  entries we overlap with.

  As you can see the old hash function ended up with all 1 million
  entries in their own bucket, whereas the new one they are only
  distributed among ~12.5k buckets, which is why we're using so much
  more CPU in __d_lookup".

The reason for this hash regression is two-fold:

 - On 64-bit architectures the down-mixing of the original 64-bit
   word-at-a-time hash into the final 32-bit hash value is very
   simplistic and suboptimal, and just adds the two 32-bit parts
   together.

   In particular, because there is no bit shuffling and the mixing
   boundary is also a byte boundary, similar character patterns in the
   low and high word easily end up just canceling each other out.

 - the old byte-at-a-time hash mixed each byte into the final hash as it
   hashed the path component name, resulting in the low bits of the hash
   generally being a good source of hash data.  That is not true for the
   word-at-a-time case, and the hash data is distributed among all the
   bits.

The fix is the same in both cases: do a better job of mixing the bits up
and using as much of the hash data as possible.  We already have the
"hash_32|64()" functions to do that.
Reported-by: default avatarJosef Bacik <jbacik@fb.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chris Mason <clm@fb.com>
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a8be8af1
    • Mario Kleiner's avatar
      drm/nouveau: Bump version from 1.1.1 to 1.1.2 · d7fbe53d
      Mario Kleiner authored 
      commit 7820e5ee upstream.

Linux 3.16 fixed multiple bugs in kms pageflip completion events
and timestamping, which were originally introduced in Linux 3.13.

These fixes have been backported to all stable kernels since 3.13.

However, the userspace nouveau-ddx needs to be aware if it is
running on a kernel on which these bugs are fixed, or not.

Bump the patchlevel of the drm driver version to signal this,
so backporting this patch to stable 3.13+ kernels will give the
ddx the required info.
Signed-off-by: default avatarMario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: default avatarBen Skeggs <bskeggs@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d7fbe53d
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