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

From: Changwei Zou

Date: Mon Oct 19 2026 - 22:55:05 EST


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@xxxxxxxxxxxxx>
Assisted-by: OpenCode:claude-sonnet-4.6
Reviewed-by: Sahil Malhotra <sahil.malhotra@xxxxxxx>
---
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