d418ee2c4f
commit dcaca01a42cc2c425154a13412b4124293a6e11e upstream.
skcipher_walk_done() assumes it's a bug if, after the "slow" path is
executed where the next chunk of data is processed via a bounce buffer,
the algorithm says it didn't process all bytes. Thus it WARNs on this.
However, this can happen legitimately when the message needs to be
evenly divisible into "blocks" but isn't, and the algorithm has a
'walksize' greater than the block size. For example, ecb-aes-neonbs
sets 'walksize' to 128 bytes and only supports messages evenly divisible
into 16-byte blocks. If, say, 17 message bytes remain but they straddle
scatterlist elements, the skcipher_walk code will take the "slow" path
and pass the algorithm all 17 bytes in the bounce buffer. But the
algorithm will only be able to process 16 bytes, triggering the WARN.
Fix this by just removing the WARN_ON(). Returning -EINVAL, as the code
already does, is the right behavior.
This bug was detected by my patches that improve testmgr to fuzz
algorithms against their generic implementation.
Fixes: b286d8b1a690 ("crypto: skcipher - Add skcipher walk interface")
Cc: <stable@vger.kernel.org> # v4.10+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.