crypto: drbg - wait for crypto op not signal safe

commit a5dfefb1c3f3db81662556393fd9283511e08430 upstream.

drbg_kcapi_sym_ctr() 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 output buffer.

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/crypto/drbg.c b/crypto/drbg.c
index 053035b..123d211 100644 (file)
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1768,9 +1768,8 @@ static int drbg_kcapi_sym_ctr(struct drbg_state *drbg,
                        break;
                case -EINPROGRESS:
                case -EBUSY:
-                       ret = wait_for_completion_interruptible(
-                               &drbg->ctr_completion);
-                       if (!ret && !drbg->ctr_async_err) {
+                       wait_for_completion(&drbg->ctr_completion);
+                       if (!drbg->ctr_async_err) {
                                reinit_completion(&drbg->ctr_completion);
                                break;
                        }