[PATCH v2 2/2] s390/crypto: Handle cpacf_kma() return code

[Harald Freudenberger <freude@linux.ibm.com>]

Now that cpacf_kma() returns the condition code, check it and bail out
with -EIO on any non-zero result. In practice CC 1 and CC 2 cannot
occur: the GCM function codes are clear-key only, and the scatterwalk
loop ensures block-aligned chunks with LAAD/LPC set on the final call.
However, it is a defensive improvement, not a bug fix.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
---
 arch/s390/crypto/aes_s390.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/arch/s390/crypto/aes_s390.c b/arch/s390/crypto/aes_s390.c
index 62edc66d5478..0e35cca35914 100644
--- a/arch/s390/crypto/aes_s390.c
+++ b/arch/s390/crypto/aes_s390.c
@@ -889,10 +889,13 @@ static int gcm_aes_crypt(struct aead_request *req, unsigned int flags)
 		if (aad_bytes > 0)
 			memcpy(gw_out.ptr, gw_in.ptr, aad_bytes);
 
-		cpacf_kma(ctx->fc | flags, &param,
-			  gw_out.ptr + aad_bytes,
-			  gw_in.ptr + aad_bytes, pc_bytes,
-			  gw_in.ptr, aad_bytes);
+		if (cpacf_kma(ctx->fc | flags, &param,
+			      gw_out.ptr + aad_bytes,
+			      gw_in.ptr + aad_bytes, pc_bytes,
+			      gw_in.ptr, aad_bytes)) {
+			ret = -EIO;
+			goto out;
+		}
 
 		n = aad_bytes + pc_bytes;
 		if (gcm_in_walk_done(&gw_in, n) != n)
-- 
2.43.0