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SubjectRe: Remaining crypto API regressions with CONFIG_VMAP_STACK
On Sun, Dec 11, 2016 at 11:13:55AM -0800, Andy Lutomirski wrote:
> On Fri, Dec 9, 2016 at 3:08 PM, Eric Biggers <ebiggers3@gmail.com> wrote:
> > In the 4.9 kernel, virtually-mapped stacks will be supported and enabled by
> > default on x86_64. This has been exposing a number of problems in which
> > on-stack buffers are being passed into the crypto API, which to support crypto
> > accelerators operates on 'struct page' rather than on virtual memory.
> >
>
> > fs/cifs/smbencrypt.c:96
>
> This should use crypto_cipher_encrypt_one(), I think.
>
> --Andy

Yes, I believe that's correct. It encrypts 8 bytes with ecb(des) which is
equivalent to simply encrypting one block with DES. Maybe try the following
(untested):

static int
smbhash(unsigned char *out, const unsigned char *in, unsigned char *key)
{
unsigned char key2[8];
struct crypto_cipher *cipher;

str_to_key(key, key2);

cipher = crypto_alloc_cipher("des", 0, 0);
if (IS_ERR(cipher)) {
cifs_dbg(VFS, "could not allocate des cipher\n");
return PTR_ERR(cipher);
}

crypto_cipher_setkey(cipher, key2, 8);

crypto_cipher_encrypt_one(cipher, out, in);

crypto_free_cipher(cipher);
return 0;
}

- Eric

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