dm crypt: fix access beyond the end of allocated space

commit d49ec52ff6ddcda178fc2476a109cf1bd1fa19ed upstream.

The DM crypt target accesses memory beyond allocated space resulting in
a crash on 32 bit x86 systems.

This bug is very old (it dates back to 2.6.25 commit 3a7f6c990ad04 "dm
crypt: use async crypto").  However, this bug was masked by the fact
that kmalloc rounds the size up to the next power of two.  This bug
wasn't exposed until 3.17-rc1 commit 298a9fa08a ("dm crypt: use per-bio
data").  By switching to using per-bio data there was no longer any
padding beyond the end of a dm-crypt allocated memory block.

To minimize allocation overhead dm-crypt puts several structures into one
block allocated with kmalloc.  The block holds struct ablkcipher_request,
cipher-specific scratch pad (crypto_ablkcipher_reqsize(any_tfm(cc))),
struct dm_crypt_request and an initialization vector.

The variable dmreq_start is set to offset of struct dm_crypt_request
within this memory block.  dm-crypt allocates the block with this size:
cc->dmreq_start + sizeof(struct dm_crypt_request) + cc->iv_size.

When accessing the initialization vector, dm-crypt uses the function
iv_of_dmreq, which performs this calculation: ALIGN((unsigned long)(dmreq
+ 1), crypto_ablkcipher_alignmask(any_tfm(cc)) + 1).

dm-crypt allocated "cc->iv_size" bytes beyond the end of dm_crypt_request
structure.  However, when dm-crypt accesses the initialization vector, it
takes a pointer to the end of dm_crypt_request, aligns it, and then uses
it as the initialization vector.  If the end of dm_crypt_request is not
aligned on a crypto_ablkcipher_alignmask(any_tfm(cc)) boundary the
alignment causes the initialization vector to point beyond the allocated
space.

Fix this bug by calculating the variable iv_size_padding and adding it
to the allocated size.

Also correct the alignment of dm_crypt_request.  struct dm_crypt_request
is specific to dm-crypt (it isn't used by the crypto subsystem at all),
so it is aligned on __alignof__(struct dm_crypt_request).

Also align per_bio_data_size on ARCH_KMALLOC_MINALIGN, so that it is
aligned as if the block was allocated with kmalloc.

Reported-by: Krzysztof Kolasa <kkolasa@winsoft.pl>
Tested-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
[lizf: Backported by Mikulas]
Signed-off-by: Zefan Li <lizefan@huawei.com>
ext4: propagate errors up to ext4_find_entry()'s callers
ext4: avoid trying to kfree an ERR_PTR pointer
nl80211: clear skb cb before passing to netlink
perf: Handle compat ioctl

commit b3f207855f57b9c8f43a547a801340bb5cbc59e5 upstream.

When running a 32-bit userspace on a 64-bit kernel (eg. i386
application on x86_64 kernel or 32-bit arm userspace on arm64
kernel) some of the perf ioctls must be treated with special
care, as they have a pointer size encoded in the command.

For example, PERF_EVENT_IOC_ID in 32-bit world will be encoded
as 0x80042407, but 64-bit kernel will expect 0x80082407. In
result the ioctl will fail returning -ENOTTY.

This patch solves the problem by adding code fixing up the
size as compat_ioctl file operation.

Reported-by: Drew Richardson <drew.richardson@arm.com>
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1402671812-9078-1-git-send-email-pawel.moll@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
[lizf: Backported to 3.4 by David Ahern]
Signed-off-by: Zefan Li <lizefan@huawei.com>
lowmemorykiller: Account for highmem during kswapd reclaim

Currently most memory reclaim is done through kswapd.
Since kswapd uses a gfp mask of GFP_KERNEL, and because
the lowmemorykiller is zone aware, the lowmemorykiller will
ignore highmem most of the time.
This results in the lowmemorykiller being overly aggressive.

The fix to this issue is to allow the lowmemorykiller to
count highmem when being called by the kswapd if the lowmem
watermarks are satisfied.

Bug: 17626969
Change-Id: I938644584f374763d10d429d835e74daa4854a38
Signed-off-by: Liam Mark <lmark@codeaurora.org>
Signed-off-by: Naveen Ramaraj <nramaraj@codeaurora.org>
mm: Increase number of GFP masks

The __GFP_CMA mask is now placed after all available GFP masks.
With this we need to increase the total number of GFP flags.
Do so accordingly.

Bug: 17626969
CRs-Fixed: 648978
Change-Id: I53f5f064ac16a50ee10c84ff2bb50fdb7e085bd0
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Naveen Ramaraj <nramaraj@codeaurora.org>
Revert "block: Add URGENT request notification support to CFQ scheduler"

This reverts commit b0c1ab4665e29c846464af9fe3bb27bae9f08bbb.
Revert "bfq v7r6 patch3"

This reverts commit 4ef8bac81b4a480ad44de70fad95493111e62e02.
Revert "bfq v7r6 patch2"

This reverts commit 606029fb05ffe058c147797cc14303b5e2495dbd.
Revert "bfq v7r6 patch1"

This reverts commit 98b4d5fecf0c03e142175a05f9752f80a5757348.
cfq io scheduler as default
new helper: single_open_size()

Same as single_open(), but preallocates the buffer of given size.
Doesn't make any sense for sizes up to PAGE_SIZE and doesn't make
sense if output of show() exceeds PAGE_SIZE only rarely - seq_read()
will take care of growing the buffer and redoing show().  If you
_know_ that it will be large, it might make more sense to look into
saner iterator, rather than go with single-shot one.  If that's
impossible, single_open_size() might be for you.

Again, don't use that without a good reason; occasionally that's really
the best way to go, but very often there are better solutions.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
fs/seq_file: fallback to vmalloc allocation
fs/seq_file: Use vmalloc by default for allocations > PAGE_SIZE

Some OOM implementations are pretty trigger happy when it comes to
releasing memory for kmalloc() allocations.  We might as well head
straight to vmalloc for allocations over PAGE_SIZE.

Change-Id: Ic0dedbadc8bf551d34cc5d77c8073938d4adef80
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
nick kvfree() from apparmor