<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include, branch v3.2.63</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>slab/mempolicy: always use local policy from interrupt context</title>
<updated>2014-09-13T22:41:50+00:00</updated>
<author>
<name>Andi Kleen</name>
<email>ak@linux.intel.com</email>
</author>
<published>2012-06-09T09:40:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1a971336c449271b091fcdb3c13d535bb04bf782'/>
<id>1a971336c449271b091fcdb3c13d535bb04bf782</id>
<content type='text'>
commit e7b691b085fda913830e5280ae6f724b2a63c824 upstream.

slab_node() could access current-&gt;mempolicy from interrupt context.
However there's a race condition during exit where the mempolicy
is first freed and then the pointer zeroed.

Using this from interrupts seems bogus anyways. The interrupt
will interrupt a random process and therefore get a random
mempolicy. Many times, this will be idle's, which noone can change.

Just disable this here and always use local for slab
from interrupts. I also cleaned up the callers of slab_node a bit
which always passed the same argument.

I believe the original mempolicy code did that in fact,
so it's likely a regression.

v2: send version with correct logic
v3: simplify. fix typo.
Reported-by: Arun Sharma &lt;asharma@fb.com&gt;
Cc: penberg@kernel.org
Cc: cl@linux.com
Signed-off-by: Andi Kleen &lt;ak@linux.intel.com&gt;
[tdmackey@twitter.com: Rework control flow based on feedback from
cl@linux.com, fix logic, and cleanup current task_struct reference]
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Acked-by: Christoph Lameter &lt;cl@linux.com&gt;
Acked-by: KOSAKI Motohiro &lt;kosaki.motohiro@jp.fujitsu.com&gt;
Signed-off-by: David Mackey &lt;tdmackey@twitter.com&gt;
Signed-off-by: Pekka Enberg &lt;penberg@kernel.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit e7b691b085fda913830e5280ae6f724b2a63c824 upstream.

slab_node() could access current-&gt;mempolicy from interrupt context.
However there's a race condition during exit where the mempolicy
is first freed and then the pointer zeroed.

Using this from interrupts seems bogus anyways. The interrupt
will interrupt a random process and therefore get a random
mempolicy. Many times, this will be idle's, which noone can change.

Just disable this here and always use local for slab
from interrupts. I also cleaned up the callers of slab_node a bit
which always passed the same argument.

I believe the original mempolicy code did that in fact,
so it's likely a regression.

v2: send version with correct logic
v3: simplify. fix typo.
Reported-by: Arun Sharma &lt;asharma@fb.com&gt;
Cc: penberg@kernel.org
Cc: cl@linux.com
Signed-off-by: Andi Kleen &lt;ak@linux.intel.com&gt;
[tdmackey@twitter.com: Rework control flow based on feedback from
cl@linux.com, fix logic, and cleanup current task_struct reference]
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Acked-by: Christoph Lameter &lt;cl@linux.com&gt;
Acked-by: KOSAKI Motohiro &lt;kosaki.motohiro@jp.fujitsu.com&gt;
Signed-off-by: David Mackey &lt;tdmackey@twitter.com&gt;
Signed-off-by: Pekka Enberg &lt;penberg@kernel.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ip: make IP identifiers less predictable</title>
<updated>2014-09-13T22:41:48+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2014-07-26T06:58:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bf63acfdbf5c15e482a0b31043d666f3d3b1cf30'/>
<id>bf63acfdbf5c15e482a0b31043d666f3d3b1cf30</id>
<content type='text'>
[ Upstream commit 04ca6973f7c1a0d8537f2d9906a0cf8e69886d75 ]

In "Counting Packets Sent Between Arbitrary Internet Hosts", Jeffrey and
Jedidiah describe ways exploiting linux IP identifier generation to
infer whether two machines are exchanging packets.

With commit 73f156a6e8c1 ("inetpeer: get rid of ip_id_count"), we
changed IP id generation, but this does not really prevent this
side-channel technique.

This patch adds a random amount of perturbation so that IP identifiers
for a given destination [1] are no longer monotonically increasing after
an idle period.

Note that prandom_u32_max(1) returns 0, so if generator is used at most
once per jiffy, this patch inserts no hole in the ID suite and do not
increase collision probability.

This is jiffies based, so in the worst case (HZ=1000), the id can
rollover after ~65 seconds of idle time, which should be fine.

We also change the hash used in __ip_select_ident() to not only hash
on daddr, but also saddr and protocol, so that ICMP probes can not be
used to infer information for other protocols.

For IPv6, adds saddr into the hash as well, but not nexthdr.

If I ping the patched target, we can see ID are now hard to predict.

21:57:11.008086 IP (...)
    A &gt; target: ICMP echo request, seq 1, length 64
21:57:11.010752 IP (... id 2081 ...)
    target &gt; A: ICMP echo reply, seq 1, length 64

21:57:12.013133 IP (...)
    A &gt; target: ICMP echo request, seq 2, length 64
21:57:12.015737 IP (... id 3039 ...)
    target &gt; A: ICMP echo reply, seq 2, length 64

21:57:13.016580 IP (...)
    A &gt; target: ICMP echo request, seq 3, length 64
21:57:13.019251 IP (... id 3437 ...)
    target &gt; A: ICMP echo reply, seq 3, length 64

[1] TCP sessions uses a per flow ID generator not changed by this patch.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: Jeffrey Knockel &lt;jeffk@cs.unm.edu&gt;
Reported-by: Jedidiah R. Crandall &lt;crandall@cs.unm.edu&gt;
Cc: Willy Tarreau &lt;w@1wt.eu&gt;
Cc: Hannes Frederic Sowa &lt;hannes@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 04ca6973f7c1a0d8537f2d9906a0cf8e69886d75 ]

In "Counting Packets Sent Between Arbitrary Internet Hosts", Jeffrey and
Jedidiah describe ways exploiting linux IP identifier generation to
infer whether two machines are exchanging packets.

With commit 73f156a6e8c1 ("inetpeer: get rid of ip_id_count"), we
changed IP id generation, but this does not really prevent this
side-channel technique.

This patch adds a random amount of perturbation so that IP identifiers
for a given destination [1] are no longer monotonically increasing after
an idle period.

Note that prandom_u32_max(1) returns 0, so if generator is used at most
once per jiffy, this patch inserts no hole in the ID suite and do not
increase collision probability.

This is jiffies based, so in the worst case (HZ=1000), the id can
rollover after ~65 seconds of idle time, which should be fine.

We also change the hash used in __ip_select_ident() to not only hash
on daddr, but also saddr and protocol, so that ICMP probes can not be
used to infer information for other protocols.

For IPv6, adds saddr into the hash as well, but not nexthdr.

If I ping the patched target, we can see ID are now hard to predict.

21:57:11.008086 IP (...)
    A &gt; target: ICMP echo request, seq 1, length 64
21:57:11.010752 IP (... id 2081 ...)
    target &gt; A: ICMP echo reply, seq 1, length 64

21:57:12.013133 IP (...)
    A &gt; target: ICMP echo request, seq 2, length 64
21:57:12.015737 IP (... id 3039 ...)
    target &gt; A: ICMP echo reply, seq 2, length 64

21:57:13.016580 IP (...)
    A &gt; target: ICMP echo request, seq 3, length 64
21:57:13.019251 IP (... id 3437 ...)
    target &gt; A: ICMP echo reply, seq 3, length 64

[1] TCP sessions uses a per flow ID generator not changed by this patch.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: Jeffrey Knockel &lt;jeffk@cs.unm.edu&gt;
Reported-by: Jedidiah R. Crandall &lt;crandall@cs.unm.edu&gt;
Cc: Willy Tarreau &lt;w@1wt.eu&gt;
Cc: Hannes Frederic Sowa &lt;hannes@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>inetpeer: get rid of ip_id_count</title>
<updated>2014-09-13T22:41:48+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2014-06-02T12:26:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=64b5c251d5b2cee4a0f697bfb90d79263f6dd517'/>
<id>64b5c251d5b2cee4a0f697bfb90d79263f6dd517</id>
<content type='text'>
[ Upstream commit 73f156a6e8c1074ac6327e0abd1169e95eb66463 ]

Ideally, we would need to generate IP ID using a per destination IP
generator.

linux kernels used inet_peer cache for this purpose, but this had a huge
cost on servers disabling MTU discovery.

1) each inet_peer struct consumes 192 bytes

2) inetpeer cache uses a binary tree of inet_peer structs,
   with a nominal size of ~66000 elements under load.

3) lookups in this tree are hitting a lot of cache lines, as tree depth
   is about 20.

4) If server deals with many tcp flows, we have a high probability of
   not finding the inet_peer, allocating a fresh one, inserting it in
   the tree with same initial ip_id_count, (cf secure_ip_id())

5) We garbage collect inet_peer aggressively.

IP ID generation do not have to be 'perfect'

Goal is trying to avoid duplicates in a short period of time,
so that reassembly units have a chance to complete reassembly of
fragments belonging to one message before receiving other fragments
with a recycled ID.

We simply use an array of generators, and a Jenkin hash using the dst IP
as a key.

ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it
belongs (it is only used from this file)

secure_ip_id() and secure_ipv6_id() no longer are needed.

Rename ip_select_ident_more() to ip_select_ident_segs() to avoid
unnecessary decrement/increment of the number of segments.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 73f156a6e8c1074ac6327e0abd1169e95eb66463 ]

Ideally, we would need to generate IP ID using a per destination IP
generator.

linux kernels used inet_peer cache for this purpose, but this had a huge
cost on servers disabling MTU discovery.

1) each inet_peer struct consumes 192 bytes

2) inetpeer cache uses a binary tree of inet_peer structs,
   with a nominal size of ~66000 elements under load.

3) lookups in this tree are hitting a lot of cache lines, as tree depth
   is about 20.

4) If server deals with many tcp flows, we have a high probability of
   not finding the inet_peer, allocating a fresh one, inserting it in
   the tree with same initial ip_id_count, (cf secure_ip_id())

5) We garbage collect inet_peer aggressively.

IP ID generation do not have to be 'perfect'

Goal is trying to avoid duplicates in a short period of time,
so that reassembly units have a chance to complete reassembly of
fragments belonging to one message before receiving other fragments
with a recycled ID.

We simply use an array of generators, and a Jenkin hash using the dst IP
as a key.

ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it
belongs (it is only used from this file)

secure_ip_id() and secure_ipv6_id() no longer are needed.

Rename ip_select_ident_more() to ip_select_ident_segs() to avoid
unnecessary decrement/increment of the number of segments.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netlabel: fix a problem when setting bits below the previously lowest bit</title>
<updated>2014-09-13T22:41:42+00:00</updated>
<author>
<name>Paul Moore</name>
<email>pmoore@redhat.com</email>
</author>
<published>2014-08-01T15:17:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=33401ce96ad0b9ba39a5aff56ef25c63859f347d'/>
<id>33401ce96ad0b9ba39a5aff56ef25c63859f347d</id>
<content type='text'>
commit 41c3bd2039e0d7b3dc32313141773f20716ec524 upstream.

The NetLabel category (catmap) functions have a problem in that they
assume categories will be set in an increasing manner, e.g. the next
category set will always be larger than the last.  Unfortunately, this
is not a valid assumption and could result in problems when attempting
to set categories less than the startbit in the lowest catmap node.
In some cases kernel panics and other nasties can result.

This patch corrects the problem by checking for this and allocating a
new catmap node instance and placing it at the front of the list.

Reported-by: Christian Evans &lt;frodox@zoho.com&gt;
Signed-off-by: Paul Moore &lt;pmoore@redhat.com&gt;
Tested-by: Casey Schaufler &lt;casey@schaufler-ca.com&gt;
[bwh: Backported to 3.2: adjust filename for SMACK]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 41c3bd2039e0d7b3dc32313141773f20716ec524 upstream.

The NetLabel category (catmap) functions have a problem in that they
assume categories will be set in an increasing manner, e.g. the next
category set will always be larger than the last.  Unfortunately, this
is not a valid assumption and could result in problems when attempting
to set categories less than the startbit in the lowest catmap node.
In some cases kernel panics and other nasties can result.

This patch corrects the problem by checking for this and allocating a
new catmap node instance and placing it at the front of the list.

Reported-by: Christian Evans &lt;frodox@zoho.com&gt;
Signed-off-by: Paul Moore &lt;pmoore@redhat.com&gt;
Tested-by: Casey Schaufler &lt;casey@schaufler-ca.com&gt;
[bwh: Backported to 3.2: adjust filename for SMACK]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mnt: Change the default remount atime from relatime to the existing value</title>
<updated>2014-09-13T22:41:41+00:00</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2014-07-29T00:36:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=24a26ff9e1bd26f50617b0bac745141dbc226e45'/>
<id>24a26ff9e1bd26f50617b0bac745141dbc226e45</id>
<content type='text'>
commit ffbc6f0ead47fa5a1dc9642b0331cb75c20a640e upstream.

Since March 2009 the kernel has treated the state that if no
MS_..ATIME flags are passed then the kernel defaults to relatime.

Defaulting to relatime instead of the existing atime state during a
remount is silly, and causes problems in practice for people who don't
specify any MS_...ATIME flags and to get the default filesystem atime
setting.  Those users may encounter a permission error because the
default atime setting does not work.

A default that does not work and causes permission problems is
ridiculous, so preserve the existing value to have a default
atime setting that is always guaranteed to work.

Using the default atime setting in this way is particularly
interesting for applications built to run in restricted userspace
environments without /proc mounted, as the existing atime mount
options of a filesystem can not be read from /proc/mounts.

In practice this fixes user space that uses the default atime
setting on remount that are broken by the permission checks
keeping less privileged users from changing more privileged users
atime settings.

Acked-by: Serge E. Hallyn &lt;serge.hallyn@ubuntu.com&gt;
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
[bwh: Backported to 3.2: add definition of MNT_ATIME_MASK, as we don't
 need the fix that introduced that definition upstream]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit ffbc6f0ead47fa5a1dc9642b0331cb75c20a640e upstream.

Since March 2009 the kernel has treated the state that if no
MS_..ATIME flags are passed then the kernel defaults to relatime.

Defaulting to relatime instead of the existing atime state during a
remount is silly, and causes problems in practice for people who don't
specify any MS_...ATIME flags and to get the default filesystem atime
setting.  Those users may encounter a permission error because the
default atime setting does not work.

A default that does not work and causes permission problems is
ridiculous, so preserve the existing value to have a default
atime setting that is always guaranteed to work.

Using the default atime setting in this way is particularly
interesting for applications built to run in restricted userspace
environments without /proc mounted, as the existing atime mount
options of a filesystem can not be read from /proc/mounts.

In practice this fixes user space that uses the default atime
setting on remount that are broken by the permission checks
keeping less privileged users from changing more privileged users
atime settings.

Acked-by: Serge E. Hallyn &lt;serge.hallyn@ubuntu.com&gt;
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
[bwh: Backported to 3.2: add definition of MNT_ATIME_MASK, as we don't
 need the fix that introduced that definition upstream]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libata: introduce ata_host-&gt;n_tags to avoid oops on SAS controllers</title>
<updated>2014-08-06T17:07:42+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2014-07-23T13:05:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e0747c72fec37e019efffb52fc23b69457cebd27'/>
<id>e0747c72fec37e019efffb52fc23b69457cebd27</id>
<content type='text'>
commit 1a112d10f03e83fb3a2fdc4c9165865dec8a3ca6 upstream.

1871ee134b73 ("libata: support the ata host which implements a queue
depth less than 32") directly used ata_port-&gt;scsi_host-&gt;can_queue from
ata_qc_new() to determine the number of tags supported by the host;
unfortunately, SAS controllers doing SATA don't initialize -&gt;scsi_host
leading to the following oops.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000058
 IP: [&lt;ffffffff814e0618&gt;] ata_qc_new_init+0x188/0x1b0
 PGD 0
 Oops: 0002 [#1] SMP
 Modules linked in: isci libsas scsi_transport_sas mgag200 drm_kms_helper ttm
 CPU: 1 PID: 518 Comm: udevd Not tainted 3.16.0-rc6+ #62
 Hardware name: Intel Corporation S2600CO/S2600CO, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013
 task: ffff880c1a00b280 ti: ffff88061a000000 task.ti: ffff88061a000000
 RIP: 0010:[&lt;ffffffff814e0618&gt;]  [&lt;ffffffff814e0618&gt;] ata_qc_new_init+0x188/0x1b0
 RSP: 0018:ffff88061a003ae8  EFLAGS: 00010012
 RAX: 0000000000000001 RBX: ffff88000241ca80 RCX: 00000000000000fa
 RDX: 0000000000000020 RSI: 0000000000000020 RDI: ffff8806194aa298
 RBP: ffff88061a003ae8 R08: ffff8806194a8000 R09: 0000000000000000
 R10: 0000000000000000 R11: ffff88000241ca80 R12: ffff88061ad58200
 R13: ffff8806194aa298 R14: ffffffff814e67a0 R15: ffff8806194a8000
 FS:  00007f3ad7fe3840(0000) GS:ffff880627620000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000058 CR3: 000000061a118000 CR4: 00000000001407e0
 Stack:
  ffff88061a003b20 ffffffff814e96e1 ffff88000241ca80 ffff88061ad58200
  ffff8800b6bf6000 ffff880c1c988000 ffff880619903850 ffff88061a003b68
  ffffffffa0056ce1 ffff88061a003b48 0000000013d6e6f8 ffff88000241ca80
 Call Trace:
  [&lt;ffffffff814e96e1&gt;] ata_sas_queuecmd+0xa1/0x430
  [&lt;ffffffffa0056ce1&gt;] sas_queuecommand+0x191/0x220 [libsas]
  [&lt;ffffffff8149afee&gt;] scsi_dispatch_cmd+0x10e/0x300
  [&lt;ffffffff814a3bc5&gt;] scsi_request_fn+0x2f5/0x550
  [&lt;ffffffff81317613&gt;] __blk_run_queue+0x33/0x40
  [&lt;ffffffff8131781a&gt;] queue_unplugged+0x2a/0x90
  [&lt;ffffffff8131ceb4&gt;] blk_flush_plug_list+0x1b4/0x210
  [&lt;ffffffff8131d274&gt;] blk_finish_plug+0x14/0x50
  [&lt;ffffffff8117eaa8&gt;] __do_page_cache_readahead+0x198/0x1f0
  [&lt;ffffffff8117ee21&gt;] force_page_cache_readahead+0x31/0x50
  [&lt;ffffffff8117ee7e&gt;] page_cache_sync_readahead+0x3e/0x50
  [&lt;ffffffff81172ac6&gt;] generic_file_read_iter+0x496/0x5a0
  [&lt;ffffffff81219897&gt;] blkdev_read_iter+0x37/0x40
  [&lt;ffffffff811e307e&gt;] new_sync_read+0x7e/0xb0
  [&lt;ffffffff811e3734&gt;] vfs_read+0x94/0x170
  [&lt;ffffffff811e43c6&gt;] SyS_read+0x46/0xb0
  [&lt;ffffffff811e33d1&gt;] ? SyS_lseek+0x91/0xb0
  [&lt;ffffffff8171ee29&gt;] system_call_fastpath+0x16/0x1b
 Code: 00 00 00 88 50 29 83 7f 08 01 19 d2 83 e2 f0 83 ea 50 88 50 34 c6 81 1d 02 00 00 40 c6 81 17 02 00 00 00 5d c3 66 0f 1f 44 00 00 &lt;89&gt; 14 25 58 00 00 00

Fix it by introducing ata_host-&gt;n_tags which is initialized to
ATA_MAX_QUEUE - 1 in ata_host_init() for SAS controllers and set to
scsi_host_template-&gt;can_queue in ata_host_register() for !SAS ones.
As SAS hosts are never registered, this will give them the same
ATA_MAX_QUEUE - 1 as before.  Note that we can't use
scsi_host-&gt;can_queue directly for SAS hosts anyway as they can go
higher than the libata maximum.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reported-by: Mike Qiu &lt;qiudayu@linux.vnet.ibm.com&gt;
Reported-by: Jesse Brandeburg &lt;jesse.brandeburg@gmail.com&gt;
Reported-by: Peter Hurley &lt;peter@hurleysoftware.com&gt;
Reported-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Tested-by: Alexey Kardashevskiy &lt;aik@ozlabs.ru&gt;
Fixes: 1871ee134b73 ("libata: support the ata host which implements a queue depth less than 32")
Cc: Kevin Hao &lt;haokexin@gmail.com&gt;
Cc: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 1a112d10f03e83fb3a2fdc4c9165865dec8a3ca6 upstream.

1871ee134b73 ("libata: support the ata host which implements a queue
depth less than 32") directly used ata_port-&gt;scsi_host-&gt;can_queue from
ata_qc_new() to determine the number of tags supported by the host;
unfortunately, SAS controllers doing SATA don't initialize -&gt;scsi_host
leading to the following oops.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000058
 IP: [&lt;ffffffff814e0618&gt;] ata_qc_new_init+0x188/0x1b0
 PGD 0
 Oops: 0002 [#1] SMP
 Modules linked in: isci libsas scsi_transport_sas mgag200 drm_kms_helper ttm
 CPU: 1 PID: 518 Comm: udevd Not tainted 3.16.0-rc6+ #62
 Hardware name: Intel Corporation S2600CO/S2600CO, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013
 task: ffff880c1a00b280 ti: ffff88061a000000 task.ti: ffff88061a000000
 RIP: 0010:[&lt;ffffffff814e0618&gt;]  [&lt;ffffffff814e0618&gt;] ata_qc_new_init+0x188/0x1b0
 RSP: 0018:ffff88061a003ae8  EFLAGS: 00010012
 RAX: 0000000000000001 RBX: ffff88000241ca80 RCX: 00000000000000fa
 RDX: 0000000000000020 RSI: 0000000000000020 RDI: ffff8806194aa298
 RBP: ffff88061a003ae8 R08: ffff8806194a8000 R09: 0000000000000000
 R10: 0000000000000000 R11: ffff88000241ca80 R12: ffff88061ad58200
 R13: ffff8806194aa298 R14: ffffffff814e67a0 R15: ffff8806194a8000
 FS:  00007f3ad7fe3840(0000) GS:ffff880627620000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000058 CR3: 000000061a118000 CR4: 00000000001407e0
 Stack:
  ffff88061a003b20 ffffffff814e96e1 ffff88000241ca80 ffff88061ad58200
  ffff8800b6bf6000 ffff880c1c988000 ffff880619903850 ffff88061a003b68
  ffffffffa0056ce1 ffff88061a003b48 0000000013d6e6f8 ffff88000241ca80
 Call Trace:
  [&lt;ffffffff814e96e1&gt;] ata_sas_queuecmd+0xa1/0x430
  [&lt;ffffffffa0056ce1&gt;] sas_queuecommand+0x191/0x220 [libsas]
  [&lt;ffffffff8149afee&gt;] scsi_dispatch_cmd+0x10e/0x300
  [&lt;ffffffff814a3bc5&gt;] scsi_request_fn+0x2f5/0x550
  [&lt;ffffffff81317613&gt;] __blk_run_queue+0x33/0x40
  [&lt;ffffffff8131781a&gt;] queue_unplugged+0x2a/0x90
  [&lt;ffffffff8131ceb4&gt;] blk_flush_plug_list+0x1b4/0x210
  [&lt;ffffffff8131d274&gt;] blk_finish_plug+0x14/0x50
  [&lt;ffffffff8117eaa8&gt;] __do_page_cache_readahead+0x198/0x1f0
  [&lt;ffffffff8117ee21&gt;] force_page_cache_readahead+0x31/0x50
  [&lt;ffffffff8117ee7e&gt;] page_cache_sync_readahead+0x3e/0x50
  [&lt;ffffffff81172ac6&gt;] generic_file_read_iter+0x496/0x5a0
  [&lt;ffffffff81219897&gt;] blkdev_read_iter+0x37/0x40
  [&lt;ffffffff811e307e&gt;] new_sync_read+0x7e/0xb0
  [&lt;ffffffff811e3734&gt;] vfs_read+0x94/0x170
  [&lt;ffffffff811e43c6&gt;] SyS_read+0x46/0xb0
  [&lt;ffffffff811e33d1&gt;] ? SyS_lseek+0x91/0xb0
  [&lt;ffffffff8171ee29&gt;] system_call_fastpath+0x16/0x1b
 Code: 00 00 00 88 50 29 83 7f 08 01 19 d2 83 e2 f0 83 ea 50 88 50 34 c6 81 1d 02 00 00 40 c6 81 17 02 00 00 00 5d c3 66 0f 1f 44 00 00 &lt;89&gt; 14 25 58 00 00 00

Fix it by introducing ata_host-&gt;n_tags which is initialized to
ATA_MAX_QUEUE - 1 in ata_host_init() for SAS controllers and set to
scsi_host_template-&gt;can_queue in ata_host_register() for !SAS ones.
As SAS hosts are never registered, this will give them the same
ATA_MAX_QUEUE - 1 as before.  Note that we can't use
scsi_host-&gt;can_queue directly for SAS hosts anyway as they can go
higher than the libata maximum.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reported-by: Mike Qiu &lt;qiudayu@linux.vnet.ibm.com&gt;
Reported-by: Jesse Brandeburg &lt;jesse.brandeburg@gmail.com&gt;
Reported-by: Peter Hurley &lt;peter@hurleysoftware.com&gt;
Reported-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Tested-by: Alexey Kardashevskiy &lt;aik@ozlabs.ru&gt;
Fixes: 1871ee134b73 ("libata: support the ata host which implements a queue depth less than 32")
Cc: Kevin Hao &lt;haokexin@gmail.com&gt;
Cc: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>introduce SIZE_MAX</title>
<updated>2014-08-06T17:07:42+00:00</updated>
<author>
<name>Xi Wang</name>
<email>xi.wang@gmail.com</email>
</author>
<published>2012-05-31T23:26:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b11597b7041b76aa25855db6028fad853201c54e'/>
<id>b11597b7041b76aa25855db6028fad853201c54e</id>
<content type='text'>
commit a3860c1c5dd1137db23d7786d284939c5761d517 upstream.

ULONG_MAX is often used to check for integer overflow when calculating
allocation size.  While ULONG_MAX happens to work on most systems, there
is no guarantee that `size_t' must be the same size as `long'.

This patch introduces SIZE_MAX, the maximum value of `size_t', to improve
portability and readability for allocation size validation.

Signed-off-by: Xi Wang &lt;xi.wang@gmail.com&gt;
Acked-by: Alex Elder &lt;elder@dreamhost.com&gt;
Cc: David Airlie &lt;airlied@linux.ie&gt;
Cc: Pekka Enberg &lt;penberg@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a3860c1c5dd1137db23d7786d284939c5761d517 upstream.

ULONG_MAX is often used to check for integer overflow when calculating
allocation size.  While ULONG_MAX happens to work on most systems, there
is no guarantee that `size_t' must be the same size as `long'.

This patch introduces SIZE_MAX, the maximum value of `size_t', to improve
portability and readability for allocation size validation.

Signed-off-by: Xi Wang &lt;xi.wang@gmail.com&gt;
Acked-by: Alex Elder &lt;elder@dreamhost.com&gt;
Cc: David Airlie &lt;airlied@linux.ie&gt;
Cc: Pekka Enberg &lt;penberg@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>include/linux/math64.h: add div64_ul()</title>
<updated>2014-08-06T17:07:37+00:00</updated>
<author>
<name>Alex Shi</name>
<email>alex.shi@intel.com</email>
</author>
<published>2013-06-12T21:05:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=79e70e9dc0cb707ad58ce8d3ed75b50610581edd'/>
<id>79e70e9dc0cb707ad58ce8d3ed75b50610581edd</id>
<content type='text'>
commit c2853c8df57f49620d26f317d7d43347c29bfc2e upstream.

There is div64_long() to handle the s64/long division, but no mocro do
u64/ul division.  It is necessary in some scenarios, so add this
function.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alex Shi &lt;alex.shi@intel.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c2853c8df57f49620d26f317d7d43347c29bfc2e upstream.

There is div64_long() to handle the s64/long division, but no mocro do
u64/ul division.  It is necessary in some scenarios, so add this
function.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alex Shi &lt;alex.shi@intel.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb-storage/SCSI: Add broken_fua blacklist flag</title>
<updated>2014-08-06T17:07:33+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2014-06-30T15:04:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=27bbd86f9319dbeeb588b8f43fe0ac241ad336ba'/>
<id>27bbd86f9319dbeeb588b8f43fe0ac241ad336ba</id>
<content type='text'>
commit b14bf2d0c0358140041d1c1805a674376964d0e0 upstream.

Some buggy JMicron USB-ATA bridges don't know how to translate the FUA
bit in READs or WRITEs.  This patch adds an entry in unusual_devs.h
and a blacklist flag to tell the sd driver not to use FUA.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Reported-by: Michael Büsch &lt;m@bues.ch&gt;
Tested-by: Michael Büsch &lt;m@bues.ch&gt;
Acked-by: James Bottomley &lt;James.Bottomley@HansenPartnership.com&gt;
CC: Matthew Dharm &lt;mdharm-usb@one-eyed-alien.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
[bwh: Backported to 3.2:
 - Adjust context
 - Use sd_printk() not sd_first_printk()]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit b14bf2d0c0358140041d1c1805a674376964d0e0 upstream.

Some buggy JMicron USB-ATA bridges don't know how to translate the FUA
bit in READs or WRITEs.  This patch adds an entry in unusual_devs.h
and a blacklist flag to tell the sd driver not to use FUA.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Reported-by: Michael Büsch &lt;m@bues.ch&gt;
Tested-by: Michael Büsch &lt;m@bues.ch&gt;
Acked-by: James Bottomley &lt;James.Bottomley@HansenPartnership.com&gt;
CC: Matthew Dharm &lt;mdharm-usb@one-eyed-alien.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
[bwh: Backported to 3.2:
 - Adjust context
 - Use sd_printk() not sd_first_printk()]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "net: ip, ipv6: handle gso skbs in forwarding path"</title>
<updated>2014-08-06T17:07:31+00:00</updated>
<author>
<name>Ben Hutchings</name>
<email>ben@decadent.org.uk</email>
</author>
<published>2014-07-12T20:00:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3d4a1eea8aac05f347bbfbf41b9e2f8d6f116926'/>
<id>3d4a1eea8aac05f347bbfbf41b9e2f8d6f116926</id>
<content type='text'>
This reverts commit caa5344994778a2b4725b2d75c74430f76925e4a, which
was commit fe6cc55f3a9a053482a76f5a6b2257cee51b4663 upstream.  In 3.2,
the transport header length is not calculated in the forwarding path,
so skb_gso_network_seglen() returns an incorrect result.  We also have
problems due to the local_df flag not being set correctly.

Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This reverts commit caa5344994778a2b4725b2d75c74430f76925e4a, which
was commit fe6cc55f3a9a053482a76f5a6b2257cee51b4663 upstream.  In 3.2,
the transport header length is not calculated in the forwarding path,
so skb_gso_network_seglen() returns an incorrect result.  We also have
problems due to the local_df flag not being set correctly.

Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
</feed>
