From 87f3c8956e3fea2a704c3834e0666e8fae5a529e Mon Sep 17 00:00:00 2001
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Tue, 13 Sep 2016 14:43:29 +0800
Subject: [PATCH] crypto: skcipher - Fix blkcipher walk OOM crash

commit acdb04d0b36769b3e05990c488dc74d8b7ac8060 upstream.

When we need to allocate a temporary blkcipher_walk_next and it
fails, the code is supposed to take the slow path of processing
the data block by block.  However, due to an unrelated change
we instead end up dereferencing the NULL pointer.

This patch fixes it by moving the unrelated bsize setting out
of the way so that we enter the slow path as inteded.

Fixes: 7607bd8ff03b ("[CRYPTO] blkcipher: Added blkcipher_walk_virt_block")
Reported-by: xiakaixu <xiakaixu@huawei.com>
Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[bwh: Backported to 3.2: s/walk_blocksize/blocksize/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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