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Subject[PATCH v3 12/14] crypto: caam - execute module exit point only if necessary
Date
Commit 1b46c90c8e00 ("crypto: caam - convert top level drivers to libraries")
changed entry and exit points behavior for caamalg,
caamalg_qi, caamalg_qi2, caamhash, caampkc, caamrng.

For example, previously caam_pkc_init() and caam_pkc_exit() were
module entry/exit points. This means that if an error would happen
in caam_pkc_init(), then caam_pkc_exit() wouldn't have been called.
After the mentioned commit, caam_pkc_init() and caam_pkc_exit()
are manually called - from jr.c. caam_pkc_exit() is called
unconditionally, even if caam_pkc_init() failed.

Added a global variable to keep the status of the algorithm
registration and free of resources.
The exit point of caampkc/caamrng module is executed only if the
registration was successful. Therefore we avoid double free of
resources in case the algorithm registration failed.

Fixes: 1b46c90c8e00 ("crypto: caam - convert top level drivers to libraries")
Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Reviewed-by: Horia Geanta <horia.geanta@nxp.com>
---
drivers/crypto/caam/caampkc.c | 11 +++++++++++
drivers/crypto/caam/caamrng.c | 14 +++++++++++++-
2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/caam/caampkc.c b/drivers/crypto/caam/caampkc.c
index 574428c7..cfdf7a2 100644
--- a/drivers/crypto/caam/caampkc.c
+++ b/drivers/crypto/caam/caampkc.c
@@ -29,6 +29,12 @@
/* buffer filled with zeros, used for padding */
static u8 *zero_buffer;

+/*
+ * variable used to avoid double free of resources in case
+ * algorithm registration was unsuccessful
+ */
+static bool init_done;
+
static void rsa_io_unmap(struct device *dev, struct rsa_edesc *edesc,
struct akcipher_request *req)
{
@@ -1081,6 +1087,7 @@ int caam_pkc_init(struct device *ctrldev)
struct caam_drv_private *priv = dev_get_drvdata(ctrldev);
u32 pk_inst;
int err;
+ init_done = false;

/* Determine public key hardware accelerator presence. */
if (priv->era < 10)
@@ -1105,6 +1112,7 @@ int caam_pkc_init(struct device *ctrldev)
dev_warn(ctrldev, "%s alg registration failed\n",
caam_rsa.base.cra_driver_name);
} else {
+ init_done = true;
dev_info(ctrldev, "caam pkc algorithms registered in /proc/crypto\n");
}

@@ -1113,6 +1121,9 @@ int caam_pkc_init(struct device *ctrldev)

void caam_pkc_exit(void)
{
+ if (!init_done)
+ return;
+
kfree(zero_buffer);
crypto_unregister_akcipher(&caam_rsa);
}
diff --git a/drivers/crypto/caam/caamrng.c b/drivers/crypto/caam/caamrng.c
index 54c32d5..7fbda1b 100644
--- a/drivers/crypto/caam/caamrng.c
+++ b/drivers/crypto/caam/caamrng.c
@@ -80,6 +80,12 @@ struct caam_rng_ctx {

static struct caam_rng_ctx *rng_ctx;

+/*
+ * Variable used to avoid double free of resources in case
+ * algorithm registration was unsuccessful
+ */
+static bool init_done;
+
static inline void rng_unmap_buf(struct device *jrdev, struct buf_data *bd)
{
if (bd->addr)
@@ -296,6 +302,9 @@ static struct hwrng caam_rng = {

void caam_rng_exit(void)
{
+ if (!init_done)
+ return;
+
caam_jr_free(rng_ctx->jrdev);
hwrng_unregister(&caam_rng);
kfree(rng_ctx);
@@ -307,6 +316,7 @@ int caam_rng_init(struct device *ctrldev)
u32 rng_inst;
struct caam_drv_private *priv = dev_get_drvdata(ctrldev);
int err;
+ init_done = false;

/* Check for an instantiated RNG before registration */
if (priv->era < 10)
@@ -335,8 +345,10 @@ int caam_rng_init(struct device *ctrldev)
dev_info(dev, "registering rng-caam\n");

err = hwrng_register(&caam_rng);
- if (!err)
+ if (!err) {
+ init_done = true;
return err;
+ }

free_rng_ctx:
kfree(rng_ctx);
--
2.1.0
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