swap: avoid read_swap_cache_async() race to deadlock while waiting on…

… discard I/O completion

commit cbab0e4 upstream.

read_swap_cache_async() can race against get_swap_page(), and stumble
across a SWAP_HAS_CACHE entry in the swap map whose page wasn't brought
into the swapcache yet.

This transient swap_map state is expected to be transitory, but the
actual placement of discard at scan_swap_map() inserts a wait for I/O
completion thus making the thread at read_swap_cache_async() to loop
around its -EEXIST case, while the other end at get_swap_page() is
scheduled away at scan_swap_map().  This can leave the system deadlocked
if the I/O completion happens to be waiting on the CPU waitqueue where
read_swap_cache_async() is busy looping and !CONFIG_PREEMPT.

This patch introduces a cond_resched() call to make the aforementioned
read_swap_cache_async() busy loop condition to bail out when necessary,
thus avoiding the subtle race window.

Signed-off-by: Rafael Aquini <aquini@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Shaohua Li <shli@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drm/i915: prefer VBT modes for SVDO-LVDS over EDID

commit c3456fb upstream.

In

commit 53d3b4d
Author: Egbert Eich <eich@suse.de>
Date:   Tue Jun 4 17:13:21 2013 +0200

    drm/i915/sdvo: Use &intel_sdvo->ddc instead of intel_sdvo->i2c for
DDC

Egbert Eich fixed a long-standing bug where we simply used a
non-working i2c controller to read the EDID for SDVO-LVDS panels.
Unfortunately some machines seem to not be able to cope with the mode
provided in the EDID. Specifically they seem to not be able to cope
with a 4x pixel mutliplier instead of a 2x one, which seems to have
been worked around by slightly changing the panels native mode in the
VBT so that the dotclock is just barely above 50MHz.

Since it took forever to notice the breakage it's fairly safe to
assume that at least for SDVO-LVDS panels the VBT contains fairly sane
data. So just switch around the order and use VBT modes first.

v2: Also add EDID modes just in case, and spell Egbert correctly.

v3: Elaborate a bit more about what's going on on Chris' machine.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=65524
Reported-and-tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Egbert Eich <eich@suse.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
b43: stop format string leaking into error msgs

The module parameter "fwpostfix" is userspace controllable,
unfiltered,and is used to define the firmware filename.
b43_do_request_fw() populates
ctx->errors[] on error, containing the firmware filename. b43err()
parses its arguments as a format string. For systems with b43 hardware,
this could lead to a uid-0 to ring-0 escalation.

CVE-2013-2852

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
first commit
ipv6: fix possible crashes in ip6_cork_release()

[ Upstream commit 284041e ]

commit 0178b69 ("ipv6: Copy cork options in ip6_append_data")
added some code duplication and bad error recovery, leading to potential
crash in ip6_cork_release() as kfree() could be called with garbage.

use kzalloc() to make sure this wont happen.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ALSA: usb-audio: work around Android accessory firmware bug

When the Android firmware enables the audio interfaces in accessory
mode, it always declares in the control interface's baInterfaceNr array
that interfaces 0 and 1 belong to the audio function.  However, the
accessory interface itself, if also enabled, already is at index 0 and
shifts the actual audio interface numbers to 1 and 2, which prevents the
PCM streaming interface from being seen by the host driver.

To get the PCM interface interface to work, detect when the descriptors
point to the (for this driver useless) accessory interface, and redirect
to the correct one.

Reported-by: Jeremy Rosen <jeremy.rosen@openwide.fr>
Tested-by: Jeremy Rosen <jeremy.rosen@openwide.fr>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ceph: fix statvfs fr_size

Different versions of glibc are broken in different ways, but the short
of
it is that for the time being, frsize should == bsize, and be used as
the
multiple for the blocks, free, and available fields.  This mirrors what
is
done for NFS.  The previous reporting of the page size for frsize meant
that newer glibc and df would report a very small value for the fs size.

Fixes http://tracker.ceph.com/issues/3793.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>