crypto: gcm - wait for crypto op not signal safe

commit f3ad587070d6bd961ab942b3fd7a85d00dfc934b upstream.

crypto_gcm_setkey() was using wait_for_completion_interruptible() to
wait for completion of async crypto op but if a signal occurs it
may return before DMA ops of HW crypto provider finish, thus
corrupting the data buffer that is kfree'ed in this case.

Resolve this by using wait_for_completion() instead.

Reported-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/crypto/gcm.c b/crypto/gcm.c
index dd3bf30f260bcccf304f162d2bd4741a08681565..9f740857f9f9895eec32d98b61491eaa3fbf8454 100644 (file)
--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -140,10 +140,8 @@ static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
 
        err = crypto_ablkcipher_encrypt(&data->req);
        if (err == -EINPROGRESS || err == -EBUSY) {
-               err = wait_for_completion_interruptible(
-                       &data->result.completion);
-               if (!err)
-                       err = data->result.err;
+               wait_for_completion(&data->result.completion);
+               err = data->result.err;
        }
 
        if (err)