crypto: rsa - add a check for allocation failure

[ Upstream commit d872ca165cb67112f2841ef9c37d51ef7e63d1e4 ]

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@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/crypto/rsa.c b/crypto/rsa.c
index c79613c..b9cd11f 100644 (file)
--- 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) {