crypto: caam/qi - fix IV DMA mapping and updating
authorHoria Geantă <horia.geanta@nxp.com>
Wed, 28 Mar 2018 12:39:19 +0000 (15:39 +0300)
committerHerbert Xu <herbert@gondor.apana.org.au>
Fri, 20 Apr 2018 16:58:25 +0000 (00:58 +0800)
commit3a488aaec6f343b5dc6d94529847a840bbeaf009
tree7c5d84ab51601b9f2b200aa1de3186d5558b79f3
parent115957bb3e59fcb226ce76b97af14533f239e0ac
crypto: caam/qi - fix IV DMA mapping and updating

There are two IV-related issues:
(1) crypto API does not guarantee to provide an IV buffer that is DMAable,
thus it's incorrect to DMA map it
(2) for in-place decryption, since ciphertext is overwritten with
plaintext, updated IV (req->info) will contain the last block of plaintext
(instead of the last block of ciphertext)

While these two issues could be fixed separately, it's straightforward
to fix both in the same time - by using the {ablkcipher,aead}_edesc
extended descriptor to store the IV that will be fed to the crypto engine;
this allows for fixing (2) by saving req->src[last_block] in req->info
directly, i.e. without allocating yet another temporary buffer.

A side effect of the fix is that it's no longer possible to have the IV
contiguous with req->src or req->dst.
Code checking for this case is removed.

Cc: <stable@vger.kernel.org> # 4.14+
Fixes: a68a19380522 ("crypto: caam/qi - properly set IV after {en,de}crypt")
Link: http://lkml.kernel.org/r/20170113084620.GF22022@gondor.apana.org.au
Reported-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
drivers/crypto/caam/caamalg_qi.c