Applying, thanks!--b.

On Wed, Mar 28, 2018 at 10:57:22AM -0700, Eric Biggers wrote:

make_checksum_hmac_md5() is allocating an HMAC transform and doing crypto API calls in the following order:

crypto_ahash_init()
crypto_ahash_setkey()
crypto_ahash_digest()

This is wrong because it makes no sense to init() the request before a key has been set, given that the initial state depends on the key. And digest() is short for init() + update() + final(), so in this case there's no need to explicitly call init() at all.

Before commit 9fa68f620041 ("crypto: hash - prevent using keyed hashes without setting key") the extra init() had no real effect, at least for the software HMAC implementation. (There are also hardware drivers that implement HMAC-MD5, and it's not immediately obvious how gracefully they handle init() before setkey().) But now the crypto API detects this incorrect initialization and returns -ENOKEY. This is breaking NFS mounts in some cases.

Fix it by removing the incorrect call to crypto_ahash_init().

Reported-by: Michael Young m.a.young@durham.ac.uk Fixes: 9fa68f620041 ("crypto: hash - prevent using keyed hashes without setting key") Fixes: fffdaef2eb4a ("gss_krb5: Add support for rc4-hmac encryption") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers ebiggers@google.com

---

net/sunrpc/auth_gss/gss_krb5_crypto.c | 3 --- 1 file changed, 3 deletions(-)

diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c index 12649c9fedab..8654494b4d0a 100644 --- a/net/sunrpc/auth_gss/gss_krb5_crypto.c +++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c @@ -237,9 +237,6 @@ make_checksum_hmac_md5(struct krb5_ctx *kctx, char *header, int hdrlen, ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);

• err = crypto_ahash_init(req);
• if (err)

• goto out;
  

  err = crypto_ahash_setkey(hmac_md5, cksumkey, kctx->gk5e->keylength); if (err) goto out;

-- 2.17.0.rc1.321.gba9d0f2565-goog