[PATCH] crypto: caam: Add check for kcalloc() in test_len()

[Guangshuo Li]

As kcalloc() may fail, check its return value to avoid a NULL pointer
dereference when passing the buffer to rng->read() and
print_hex_dump_debug().

Fixes: 2be0d806e25e ("crypto: caam - add a test for the RNG")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
---
 drivers/crypto/caam/caamrng.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/caam/caamrng.c b/drivers/crypto/caam/caamrng.c
index b3d14a7f4dd1..003c5e37acbe 100644
--- a/drivers/crypto/caam/caamrng.c
+++ b/drivers/crypto/caam/caamrng.c
@@ -181,7 +181,8 @@ static inline void test_len(struct hwrng *rng, size_t len, bool wait)
 	struct device *dev = ctx->ctrldev;
 
 	buf = kcalloc(CAAM_RNG_MAX_FIFO_STORE_SIZE, sizeof(u8), GFP_KERNEL);
-
+	if (!buf)
+		return;
 	while (len > 0) {
 		read_len = rng->read(rng, buf, len, wait);
 
-- 
2.43.0