<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include/linux, branch v3.18.48</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>net:Add sysctl_max_skb_frags</title>
<updated>2017-02-08T08:43:05+00:00</updated>
<author>
<name>Hans Westgaard Ry</name>
<email>hans.westgaard.ry@oracle.com</email>
</author>
<published>2016-02-03T08:26:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=df93393787a3fc3b994c5061a890b0250bae0fbc'/>
<id>df93393787a3fc3b994c5061a890b0250bae0fbc</id>
<content type='text'>
commit 5f74f82ea34c0da80ea0b49192bb5ea06e063593 upstream.

Devices may have limits on the number of fragments in an skb they support.
Current codebase uses a constant as maximum for number of fragments one
skb can hold and use.
When enabling scatter/gather and running traffic with many small messages
the codebase uses the maximum number of fragments and may thereby violate
the max for certain devices.
The patch introduces a global variable as max number of fragments.

Signed-off-by: Hans Westgaard Ry &lt;hans.westgaard.ry@oracle.com&gt;
Reviewed-by: Håkon Bugge &lt;haakon.bugge@oracle.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 5f74f82ea34c0da80ea0b49192bb5ea06e063593 upstream.

Devices may have limits on the number of fragments in an skb they support.
Current codebase uses a constant as maximum for number of fragments one
skb can hold and use.
When enabling scatter/gather and running traffic with many small messages
the codebase uses the maximum number of fragments and may thereby violate
the max for certain devices.
The patch introduces a global variable as max number of fragments.

Signed-off-by: Hans Westgaard Ry &lt;hans.westgaard.ry@oracle.com&gt;
Reviewed-by: Håkon Bugge &lt;haakon.bugge@oracle.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>blk: rq_data_dir() should not return a boolean</title>
<updated>2017-02-08T08:43:05+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-05-27T22:32:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1115c5f029831fd3a9f447094069bb01802418a1'/>
<id>1115c5f029831fd3a9f447094069bb01802418a1</id>
<content type='text'>
commit 10fbd36e362a0f367e34a7cd876a81295d8fc5ca upstream.

rq_data_dir() returns either READ or WRITE (0 == READ, 1 == WRITE), not
a boolean value.

Now, admittedly the "!= 0" doesn't really change the value (0 stays as
zero, 1 stays as one), but it's not only redundant, it confuses gcc, and
causes gcc to warn about the construct

    switch (rq_data_dir(req)) {
        case READ:
            ...
        case WRITE:
            ...

that we have in a few drivers.

Now, the gcc warning is silly and stupid (it seems to warn not about the
switch value having a different type from the case statements, but about
_any_ boolean switch value), but in this case the code itself is silly
and stupid too, so let's just change it, and get rid of warnings like
this:

  drivers/block/hd.c: In function ‘hd_request’:
  drivers/block/hd.c:630:11: warning: switch condition has boolean value [-Wswitch-bool]
     switch (rq_data_dir(req)) {

The odd '!= 0' came in when "cmd_flags" got turned into a "u64" in
commit 5953316dbf90 ("block: make rq-&gt;cmd_flags be 64-bit") and is
presumably because the old code (that just did a logical 'and' with 1)
would then end up making the type of rq_data_dir() be u64 too.

But if we want to retain the old regular integer type, let's just cast
the result to 'int' rather than use that rather odd '!= 0'.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 10fbd36e362a0f367e34a7cd876a81295d8fc5ca upstream.

rq_data_dir() returns either READ or WRITE (0 == READ, 1 == WRITE), not
a boolean value.

Now, admittedly the "!= 0" doesn't really change the value (0 stays as
zero, 1 stays as one), but it's not only redundant, it confuses gcc, and
causes gcc to warn about the construct

    switch (rq_data_dir(req)) {
        case READ:
            ...
        case WRITE:
            ...

that we have in a few drivers.

Now, the gcc warning is silly and stupid (it seems to warn not about the
switch value having a different type from the case statements, but about
_any_ boolean switch value), but in this case the code itself is silly
and stupid too, so let's just change it, and get rid of warnings like
this:

  drivers/block/hd.c: In function ‘hd_request’:
  drivers/block/hd.c:630:11: warning: switch condition has boolean value [-Wswitch-bool]
     switch (rq_data_dir(req)) {

The odd '!= 0' came in when "cmd_flags" got turned into a "u64" in
commit 5953316dbf90 ("block: make rq-&gt;cmd_flags be 64-bit") and is
presumably because the old code (that just did a logical 'and' with 1)
would then end up making the type of rq_data_dir() be u64 too.

But if we want to retain the old regular integer type, let's just cast
the result to 'int' rather than use that rather odd '!= 0'.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>usb: renesas_usbhs: fix build warning if 64-bit architecture</title>
<updated>2017-02-08T08:43:05+00:00</updated>
<author>
<name>Yoshihiro Shimoda</name>
<email>yoshihiro.shimoda.uh@renesas.com</email>
</author>
<published>2015-09-29T09:21:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e721bf1497aa8b4d115126fa1994afc9932c849f'/>
<id>e721bf1497aa8b4d115126fa1994afc9932c849f</id>
<content type='text'>
commit 9ae7ce00cc1353155b1914bfc40e8362efef7d1c upstream.

This patch fixes the following warning if 64-bit architecture environment:

./drivers/usb/renesas_usbhs/common.c:496:25: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
  dparam-&gt;type = of_id ? (u32)of_id-&gt;data : 0;

Acked-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Yoshihiro Shimoda &lt;yoshihiro.shimoda.uh@renesas.com&gt;
Signed-off-by: Felipe Balbi &lt;balbi@ti.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 9ae7ce00cc1353155b1914bfc40e8362efef7d1c upstream.

This patch fixes the following warning if 64-bit architecture environment:

./drivers/usb/renesas_usbhs/common.c:496:25: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
  dparam-&gt;type = of_id ? (u32)of_id-&gt;data : 0;

Acked-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Yoshihiro Shimoda &lt;yoshihiro.shimoda.uh@renesas.com&gt;
Signed-off-by: Felipe Balbi &lt;balbi@ti.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>module: fix types of device tables aliases</title>
<updated>2017-02-08T08:43:02+00:00</updated>
<author>
<name>Andrey Ryabinin</name>
<email>a.ryabinin@samsung.com</email>
</author>
<published>2015-02-13T22:40:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=af93ebdd005bea26ae4b2a1d83151410641e9ec6'/>
<id>af93ebdd005bea26ae4b2a1d83151410641e9ec6</id>
<content type='text'>
commit 6301939d97d079f0d3dbe71e750f4daf5d39fc33 upstream.

MODULE_DEVICE_TABLE() macro used to create aliases to device tables.
Normally alias should have the same type as aliased symbol.

Device tables are arrays, so they have 'struct type##_device_id[x]'
types. Alias created by MODULE_DEVICE_TABLE() will have non-array type -
	'struct type##_device_id'.

This inconsistency confuses compiler, it could make a wrong assumption
about variable's size which leads KASan to produce a false positive report
about out of bounds access.

For every global variable compiler calls __asan_register_globals() passing
information about global variable (address, size, size with redzone, name
...) __asan_register_globals() poison symbols redzone to detect possible
out of bounds accesses.

When symbol has an alias __asan_register_globals() will be called as for
symbol so for alias.  Compiler determines size of variable by size of
variable's type.  Alias and symbol have the same address, so if alias have
the wrong size part of memory that actually belongs to the symbol could be
poisoned as redzone of alias symbol.

By fixing type of alias symbol we will fix size of it, so
__asan_register_globals() will not poison valid memory.

Signed-off-by: Andrey Ryabinin &lt;a.ryabinin@samsung.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Konstantin Serebryany &lt;kcc@google.com&gt;
Cc: Dmitry Chernenkov &lt;dmitryc@google.com&gt;
Signed-off-by: Andrey Konovalov &lt;adech.fo@gmail.com&gt;
Cc: Yuri Gribov &lt;tetra2005@gmail.com&gt;
Cc: Konstantin Khlebnikov &lt;koct9i@gmail.com&gt;
Cc: Sasha Levin &lt;sasha.levin@oracle.com&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: Joonsoo Kim &lt;iamjoonsoo.kim@lge.com&gt;
Cc: Dave Hansen &lt;dave.hansen@intel.com&gt;
Cc: Andi Kleen &lt;andi@firstfloor.org&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: Pekka Enberg &lt;penberg@kernel.org&gt;
Cc: David Rientjes &lt;rientjes@google.com&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: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 6301939d97d079f0d3dbe71e750f4daf5d39fc33 upstream.

MODULE_DEVICE_TABLE() macro used to create aliases to device tables.
Normally alias should have the same type as aliased symbol.

Device tables are arrays, so they have 'struct type##_device_id[x]'
types. Alias created by MODULE_DEVICE_TABLE() will have non-array type -
	'struct type##_device_id'.

This inconsistency confuses compiler, it could make a wrong assumption
about variable's size which leads KASan to produce a false positive report
about out of bounds access.

For every global variable compiler calls __asan_register_globals() passing
information about global variable (address, size, size with redzone, name
...) __asan_register_globals() poison symbols redzone to detect possible
out of bounds accesses.

When symbol has an alias __asan_register_globals() will be called as for
symbol so for alias.  Compiler determines size of variable by size of
variable's type.  Alias and symbol have the same address, so if alias have
the wrong size part of memory that actually belongs to the symbol could be
poisoned as redzone of alias symbol.

By fixing type of alias symbol we will fix size of it, so
__asan_register_globals() will not poison valid memory.

Signed-off-by: Andrey Ryabinin &lt;a.ryabinin@samsung.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Konstantin Serebryany &lt;kcc@google.com&gt;
Cc: Dmitry Chernenkov &lt;dmitryc@google.com&gt;
Signed-off-by: Andrey Konovalov &lt;adech.fo@gmail.com&gt;
Cc: Yuri Gribov &lt;tetra2005@gmail.com&gt;
Cc: Konstantin Khlebnikov &lt;koct9i@gmail.com&gt;
Cc: Sasha Levin &lt;sasha.levin@oracle.com&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: Joonsoo Kim &lt;iamjoonsoo.kim@lge.com&gt;
Cc: Dave Hansen &lt;dave.hansen@intel.com&gt;
Cc: Andi Kleen &lt;andi@firstfloor.org&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: Pekka Enberg &lt;penberg@kernel.org&gt;
Cc: David Rientjes &lt;rientjes@google.com&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: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>tunnels: Don't apply GRO to multiple layers of encapsulation.</title>
<updated>2017-01-15T14:49:53+00:00</updated>
<author>
<name>Jesse Gross</name>
<email>jesse@kernel.org</email>
</author>
<published>2016-03-19T16:32:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dd4fff23f0f4c7c5414f50c091c78a7e423f85da'/>
<id>dd4fff23f0f4c7c5414f50c091c78a7e423f85da</id>
<content type='text'>
[ Upstream commit fac8e0f579695a3ecbc4d3cac369139d7f819971 ]

When drivers express support for TSO of encapsulated packets, they
only mean that they can do it for one layer of encapsulation.
Supporting additional levels would mean updating, at a minimum,
more IP length fields and they are unaware of this.

No encapsulation device expresses support for handling offloaded
encapsulated packets, so we won't generate these types of frames
in the transmit path. However, GRO doesn't have a check for
multiple levels of encapsulation and will attempt to build them.

UDP tunnel GRO actually does prevent this situation but it only
handles multiple UDP tunnels stacked on top of each other. This
generalizes that solution to prevent any kind of tunnel stacking
that would cause problems.

Fixes: bf5a755f ("net-gre-gro: Add GRE support to the GRO stack")
Signed-off-by: Jesse Gross &lt;jesse@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit fac8e0f579695a3ecbc4d3cac369139d7f819971 ]

When drivers express support for TSO of encapsulated packets, they
only mean that they can do it for one layer of encapsulation.
Supporting additional levels would mean updating, at a minimum,
more IP length fields and they are unaware of this.

No encapsulation device expresses support for handling offloaded
encapsulated packets, so we won't generate these types of frames
in the transmit path. However, GRO doesn't have a check for
multiple levels of encapsulation and will attempt to build them.

UDP tunnel GRO actually does prevent this situation but it only
handles multiple UDP tunnels stacked on top of each other. This
generalizes that solution to prevent any kind of tunnel stacking
that would cause problems.

Fixes: bf5a755f ("net-gre-gro: Add GRE support to the GRO stack")
Signed-off-by: Jesse Gross &lt;jesse@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: Use more bit fields in napi_gro_cb</title>
<updated>2017-01-15T14:49:53+00:00</updated>
<author>
<name>Tom Herbert</name>
<email>therbert@google.com</email>
</author>
<published>2015-02-11T00:30:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=218e207ff7797e93d3331a2b1e7ad7ea9dc981d8'/>
<id>218e207ff7797e93d3331a2b1e7ad7ea9dc981d8</id>
<content type='text'>
[ Upstream commit baa32ff42871f2d4aca9c08c9403d0e497325564 ]

This patch moves the free and same_flow fields to be bit fields
(2 and 1 bit sized respectively). This frees up some space for u16's.

Signed-off-by: Tom Herbert &lt;therbert@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit baa32ff42871f2d4aca9c08c9403d0e497325564 ]

This patch moves the free and same_flow fields to be bit fields
(2 and 1 bit sized respectively). This frees up some space for u16's.

Signed-off-by: Tom Herbert &lt;therbert@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: dev: fix deadlock reported after bus-off</title>
<updated>2016-12-23T14:41:16+00:00</updated>
<author>
<name>Sergei Miroshnichenko</name>
<email>sergeimir@emcraft.com</email>
</author>
<published>2016-09-07T13:51:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5e5920acffa330fabb1a7df2c340d747d2a13e37'/>
<id>5e5920acffa330fabb1a7df2c340d747d2a13e37</id>
<content type='text'>
[ Upstream commit 9abefcb1aaa58b9d5aa40a8bb12c87d02415e4c8 ]

A timer was used to restart after the bus-off state, leading to a
relatively large can_restart() executed in an interrupt context,
which in turn sets up pinctrl. When this happens during system boot,
there is a high probability of grabbing the pinctrl_list_mutex,
which is locked already by the probe() of other device, making the
kernel suspect a deadlock condition [1].

To resolve this issue, the restart_timer is replaced by a delayed
work.

[1] https://github.com/victronenergy/venus/issues/24

Signed-off-by: Sergei Miroshnichenko &lt;sergeimir@emcraft.com&gt;
Cc: linux-stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 9abefcb1aaa58b9d5aa40a8bb12c87d02415e4c8 ]

A timer was used to restart after the bus-off state, leading to a
relatively large can_restart() executed in an interrupt context,
which in turn sets up pinctrl. When this happens during system boot,
there is a high probability of grabbing the pinctrl_list_mutex,
which is locked already by the probe() of other device, making the
kernel suspect a deadlock condition [1].

To resolve this issue, the restart_timer is replaced by a delayed
work.

[1] https://github.com/victronenergy/venus/issues/24

Signed-off-by: Sergei Miroshnichenko &lt;sergeimir@emcraft.com&gt;
Cc: linux-stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: remove gup_flags FOLL_WRITE games from __get_user_pages()</title>
<updated>2016-10-22T19:48:09+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-10-13T20:07:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e45a502bdeae5a075257c4f061d1ff4ff0821354'/>
<id>e45a502bdeae5a075257c4f061d1ff4ff0821354</id>
<content type='text'>
[ Upstream commit 19be0eaffa3ac7d8eb6784ad9bdbc7d67ed8e619 ]

This is an ancient bug that was actually attempted to be fixed once
(badly) by me eleven years ago in commit 4ceb5db9757a ("Fix
get_user_pages() race for write access") but that was then undone due to
problems on s390 by commit f33ea7f404e5 ("fix get_user_pages bug").

In the meantime, the s390 situation has long been fixed, and we can now
fix it by checking the pte_dirty() bit properly (and do it better).  The
s390 dirty bit was implemented in abf09bed3cce ("s390/mm: implement
software dirty bits") which made it into v3.9.  Earlier kernels will
have to look at the page state itself.

Also, the VM has become more scalable, and what used a purely
theoretical race back then has become easier to trigger.

To fix it, we introduce a new internal FOLL_COW flag to mark the "yes,
we already did a COW" rather than play racy games with FOLL_WRITE that
is very fundamental, and then use the pte dirty flag to validate that
the FOLL_COW flag is still valid.

Reported-and-tested-by: Phil "not Paul" Oester &lt;kernel@linuxace.com&gt;
Acked-by: Hugh Dickins &lt;hughd@google.com&gt;
Reviewed-by: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Willy Tarreau &lt;w@1wt.eu&gt;
Cc: Nick Piggin &lt;npiggin@gmail.com&gt;
Cc: Greg Thelen &lt;gthelen@google.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 19be0eaffa3ac7d8eb6784ad9bdbc7d67ed8e619 ]

This is an ancient bug that was actually attempted to be fixed once
(badly) by me eleven years ago in commit 4ceb5db9757a ("Fix
get_user_pages() race for write access") but that was then undone due to
problems on s390 by commit f33ea7f404e5 ("fix get_user_pages bug").

In the meantime, the s390 situation has long been fixed, and we can now
fix it by checking the pte_dirty() bit properly (and do it better).  The
s390 dirty bit was implemented in abf09bed3cce ("s390/mm: implement
software dirty bits") which made it into v3.9.  Earlier kernels will
have to look at the page state itself.

Also, the VM has become more scalable, and what used a purely
theoretical race back then has become easier to trigger.

To fix it, we introduce a new internal FOLL_COW flag to mark the "yes,
we already did a COW" rather than play racy games with FOLL_WRITE that
is very fundamental, and then use the pte dirty flag to validate that
the FOLL_COW flag is still valid.

Reported-and-tested-by: Phil "not Paul" Oester &lt;kernel@linuxace.com&gt;
Acked-by: Hugh Dickins &lt;hughd@google.com&gt;
Reviewed-by: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Willy Tarreau &lt;w@1wt.eu&gt;
Cc: Nick Piggin &lt;npiggin@gmail.com&gt;
Cc: Greg Thelen &lt;gthelen@google.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fix fault_in_multipages_...() on architectures with no-op access_ok()</title>
<updated>2016-10-06T02:40:20+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@ZenIV.linux.org.uk</email>
</author>
<published>2016-09-20T19:07:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=400f32af8fa658ffd530aab033e5eb0ad419c18d'/>
<id>400f32af8fa658ffd530aab033e5eb0ad419c18d</id>
<content type='text'>
[ Upstream commit e23d4159b109167126e5bcd7f3775c95de7fee47 ]

Switching iov_iter fault-in to multipages variants has exposed an old
bug in underlying fault_in_multipages_...(); they break if the range
passed to them wraps around.  Normally access_ok() done by callers will
prevent such (and it's a guaranteed EFAULT - ERR_PTR() values fall into
such a range and they should not point to any valid objects).

However, on architectures where userland and kernel live in different
MMU contexts (e.g. s390) access_ok() is a no-op and on those a range
with a wraparound can reach fault_in_multipages_...().

Since any wraparound means EFAULT there, the fix is trivial - turn
those

    while (uaddr &lt;= end)
	    ...
into

    if (unlikely(uaddr &gt; end))
	    return -EFAULT;
    do
	    ...
    while (uaddr &lt;= end);

Reported-by: Jan Stancek &lt;jstancek@redhat.com&gt;
Tested-by: Jan Stancek &lt;jstancek@redhat.com&gt;
Cc: stable@vger.kernel.org # v3.5+
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit e23d4159b109167126e5bcd7f3775c95de7fee47 ]

Switching iov_iter fault-in to multipages variants has exposed an old
bug in underlying fault_in_multipages_...(); they break if the range
passed to them wraps around.  Normally access_ok() done by callers will
prevent such (and it's a guaranteed EFAULT - ERR_PTR() values fall into
such a range and they should not point to any valid objects).

However, on architectures where userland and kernel live in different
MMU contexts (e.g. s390) access_ok() is a no-op and on those a range
with a wraparound can reach fault_in_multipages_...().

Since any wraparound means EFAULT there, the fix is trivial - turn
those

    while (uaddr &lt;= end)
	    ...
into

    if (unlikely(uaddr &gt; end))
	    return -EFAULT;
    do
	    ...
    while (uaddr &lt;= end);

Reported-by: Jan Stancek &lt;jstancek@redhat.com&gt;
Tested-by: Jan Stancek &lt;jstancek@redhat.com&gt;
Cc: stable@vger.kernel.org # v3.5+
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fanotify: fix list corruption in fanotify_get_response()</title>
<updated>2016-10-06T02:40:20+00:00</updated>
<author>
<name>Jan Kara</name>
<email>jack@suse.cz</email>
</author>
<published>2016-09-19T21:44:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8a781b2ef81309458b9b24b51f8ad81ac7e98fe2'/>
<id>8a781b2ef81309458b9b24b51f8ad81ac7e98fe2</id>
<content type='text'>
[ Upstream commit 96d41019e3ac55f6f0115b0ce97e4f24a3d636d2 ]

fanotify_get_response() calls fsnotify_remove_event() when it finds that
group is being released from fanotify_release() (bypass_perm is set).

However the event it removes need not be only in the group's notification
queue but it can have already moved to access_list (userspace read the
event before closing the fanotify instance fd) which is protected by a
different lock.  Thus when fsnotify_remove_event() races with
fanotify_release() operating on access_list, the list can get corrupted.

Fix the problem by moving all the logic removing permission events from
the lists to one place - fanotify_release().

Fixes: 5838d4442bd5 ("fanotify: fix double free of pending permission events")
Link: http://lkml.kernel.org/r/1473797711-14111-3-git-send-email-jack@suse.cz
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Reported-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Tested-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Reviewed-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Cc: &lt;stable@vger.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: Sasha Levin &lt;alexander.levin@verizon.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 96d41019e3ac55f6f0115b0ce97e4f24a3d636d2 ]

fanotify_get_response() calls fsnotify_remove_event() when it finds that
group is being released from fanotify_release() (bypass_perm is set).

However the event it removes need not be only in the group's notification
queue but it can have already moved to access_list (userspace read the
event before closing the fanotify instance fd) which is protected by a
different lock.  Thus when fsnotify_remove_event() races with
fanotify_release() operating on access_list, the list can get corrupted.

Fix the problem by moving all the logic removing permission events from
the lists to one place - fanotify_release().

Fixes: 5838d4442bd5 ("fanotify: fix double free of pending permission events")
Link: http://lkml.kernel.org/r/1473797711-14111-3-git-send-email-jack@suse.cz
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Reported-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Tested-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Reviewed-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Cc: &lt;stable@vger.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: Sasha Levin &lt;alexander.levin@verizon.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
