[PATCH] crypto: rsa - add a check for allocation failure

[Dan Carpenter <dan.carpenter@xxxxxxxxxx>]

Static checkers insist that the mpi_alloc() allocation can fail so add
a check to prevent a NULL dereference.  Small allocations like this
can't actually fail in current kernels, but adding a check is very
simple and makes the static checkers happy.

Fixes: 6637e11e4ad2 ("crypto: rsa - allow only odd e and restrict value in FIPS mode")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
 crypto/rsa.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/crypto/rsa.c b/crypto/rsa.c
index c79613cdce6e..b9cd11fb7d36 100644
--- a/crypto/rsa.c
+++ b/crypto/rsa.c
@@ -220,6 +220,8 @@ static int rsa_check_exponent_fips(MPI e)
 	}
 
 	e_max = mpi_alloc(0);
+	if (!e_max)
+		return -ENOMEM;
 	mpi_set_bit(e_max, 256);
 
 	if (mpi_cmp(e, e_max) >= 0) {
-- 
2.42.0