crypto: rsa - add a check for allocation failure

Dan Carpenter · PlaidCat · commit 96e37ce7fdf0 · 2024-11-21T15:13:56.000-05:00
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: 6637e11 ("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>
diff --git a/crypto/rsa.c b/crypto/rsa.c
@@ -172,6 +172,8 @@ 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) {

Original file line number	Diff line number	Diff line change
`@@ -172,6 +172,8 @@ static int rsa_check_exponent_fips(MPI e)`
`172`	`172`	`}`
`173`	`173`
`174`	`174`	`e_max = mpi_alloc(0);`
	`175`	`+ if (!e_max)`
	`176`	`+ return -ENOMEM;`
`175`	`177`	`mpi_set_bit(e_max, 256);`
`176`	`178`
`177`	`179`	`if (mpi_cmp(e, e_max) >= 0) {`