Commit c5ffd608 authored by Herbert Xu's avatar Herbert Xu Committed by Ben Hutchings

crypto: skcipher - Fix blkcipher walk OOM crash

commit acdb04d0 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: 7607bd8f ("[CRYPTO] blkcipher: Added blkcipher_walk_virt_block")
Reported-by: default avatarxiakaixu <xiakaixu@huawei.com>
Reported-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Tested-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
parent 593c5692
......@@ -233,6 +233,8 @@ static int blkcipher_walk_next(struct blkcipher_desc *desc,
return blkcipher_walk_done(desc, walk, -EINVAL);
}
bsize = min(walk->walk_blocksize, n);
walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |
BLKCIPHER_WALK_DIFF);
if (!scatterwalk_aligned(&walk->in, walk->alignmask) ||
......@@ -245,7 +247,6 @@ static int blkcipher_walk_next(struct blkcipher_desc *desc,
}
}
bsize = min(walk->walk_blocksize, n);
n = scatterwalk_clamp(&walk->in, n);
n = scatterwalk_clamp(&walk->out, n);
......
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