[PATCH] crypto: zynqmp-sha - fix NULL pointer dereference in init_tfm

[Thorsten Blum <blum@kernel.org>]

zynqmp_sha_init_tfm() checks crypto_shash_statesize(tfm_ctx->fbk_tfm)
before assigning the fallback transform to it, which dereferences a NULL
pointer since the transform context is zero-initialized. Use the local
fallback_tfm pointer for the size check instead.

Fixes: c1dd353d18e5 ("crypto: zynqmp-sha - Make descsize an algorithm attribute")
Cc: stable@vger.kernel.org
Signed-off-by: Thorsten Blum <blum@kernel.org>
---
 drivers/crypto/xilinx/zynqmp-sha.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/crypto/xilinx/zynqmp-sha.c b/drivers/crypto/xilinx/zynqmp-sha.c
index 5813017b6b79..cd051e1f4275 100644
--- a/drivers/crypto/xilinx/zynqmp-sha.c
+++ b/drivers/crypto/xilinx/zynqmp-sha.c
@@ -59,7 +59,7 @@ static int zynqmp_sha_init_tfm(struct crypto_shash *hash)
 		return PTR_ERR(fallback_tfm);
 
 	if (crypto_shash_descsize(hash) <
-	    crypto_shash_statesize(tfm_ctx->fbk_tfm)) {
+	    crypto_shash_statesize(fallback_tfm)) {
 		crypto_free_shash(fallback_tfm);
 		return -EINVAL;
 	}