[PATCH v3 1/2] crypto: caam - Fix wrong unmap operations

[Changwei Zou <changwei.zou@canonical.com>]

Since priv_form only takes values FORM1/FORM2/FORM3 with no distinct
public key enumerator, rsa_pub_unmap() was not called correctly in
akcipher_do_one_req() and akcipher_enqueue_req().

Use the completion callback (rsa_pub_done vs rsa_priv_f_done) to
distinguish public from private key operations, then dispatch to the
correct unmap function based on key->priv_form.

caam_rsa_set_priv_key_form() implicitly relies on zero-initialization
for priv_form. Set priv_form = FORM1 explicitly at the head of the function
for clarity and robustness.

Fixes: bf53795025a2 ("crypto: caam - add crypto_engine support for RSA algorithms")
Signed-off-by: Changwei Zou <changwei.zou@canonical.com>
Assisted-by: OpenCode:claude-sonnet-4.6
Reviewed-by: Sahil Malhotra <sahil.malhotra@nxp.com>
---
 drivers/crypto/caam/caampkc.c | 43 +++++++++++++++++++++++++----------
 1 file changed, 31 insertions(+), 12 deletions(-)

diff --git a/drivers/crypto/caam/caampkc.c b/drivers/crypto/caam/caampkc.c
index cb001aa1de66..18a728849147 100644
--- a/drivers/crypto/caam/caampkc.c
+++ b/drivers/crypto/caam/caampkc.c
@@ -379,6 +379,7 @@ static int akcipher_do_one_req(struct crypto_engine *engine, void *areq)
 	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
 	struct caam_rsa_req_ctx *req_ctx = akcipher_request_ctx(req);
 	struct caam_rsa_ctx *ctx = akcipher_tfm_ctx_dma(tfm);
+	struct caam_rsa_key *key = &ctx->key;
 	struct device *jrdev = ctx->dev;
 	u32 *desc = req_ctx->edesc->hw_desc;
 	int ret;
@@ -391,7 +392,21 @@ static int akcipher_do_one_req(struct crypto_engine *engine, void *areq)
 		return ret;
 
 	if (ret != -EINPROGRESS) {
-		rsa_pub_unmap(jrdev, req_ctx->edesc, req);
+		if (req_ctx->akcipher_op_done == rsa_pub_done) {
+			rsa_pub_unmap(jrdev, req_ctx->edesc, req);
+		} else {
+			switch (key->priv_form) {
+			case FORM1:
+				rsa_priv_f1_unmap(jrdev, req_ctx->edesc, req);
+				break;
+			case FORM2:
+				rsa_priv_f2_unmap(jrdev, req_ctx->edesc, req);
+				break;
+			case FORM3:
+				rsa_priv_f3_unmap(jrdev, req_ctx->edesc, req);
+				break;
+			}
+		}
 		rsa_io_unmap(jrdev, req_ctx->edesc, req);
 		kfree(req_ctx->edesc);
 	} else {
@@ -691,18 +706,20 @@ static int akcipher_enqueue_req(struct device *jrdev,
 		ret = caam_jr_enqueue(jrdev, desc, cbk, req);
 
 	if ((ret != -EINPROGRESS) && (ret != -EBUSY)) {
-		switch (key->priv_form) {
-		case FORM1:
-			rsa_priv_f1_unmap(jrdev, edesc, req);
-			break;
-		case FORM2:
-			rsa_priv_f2_unmap(jrdev, edesc, req);
-			break;
-		case FORM3:
-			rsa_priv_f3_unmap(jrdev, edesc, req);
-			break;
-		default:
+		if (cbk == rsa_pub_done) {
 			rsa_pub_unmap(jrdev, edesc, req);
+		} else {
+			switch (key->priv_form) {
+			case FORM1:
+				rsa_priv_f1_unmap(jrdev, edesc, req);
+				break;
+			case FORM2:
+				rsa_priv_f2_unmap(jrdev, edesc, req);
+				break;
+			case FORM3:
+				rsa_priv_f3_unmap(jrdev, edesc, req);
+				break;
+			}
 		}
 		rsa_io_unmap(jrdev, edesc, req);
 		kfree(edesc);
@@ -992,6 +1009,8 @@ static int caam_rsa_set_priv_key_form(struct caam_rsa_ctx *ctx,
 	size_t q_sz = raw_key->q_sz;
 	unsigned aligned_size;
 
+	rsa_key->priv_form = FORM1;
+
 	rsa_key->p = caam_read_raw_data(raw_key->p, &p_sz);
 	if (!rsa_key->p)
 		return -ENOMEM;
-- 
2.43.0