crypto: api - check for ERR pointers in crypto_destroy_tfm()
Given that crypto_alloc_tfm() may return ERR pointers, and to avoid
crashes on obscure error paths where such pointers are presented to
crypto_destroy_tfm() (such as [0]), add an ERR_PTR check there
before dereferencing the second argument as a struct crypto_tfm
pointer.
[0] https://lore.kernel.org/linux-crypto/[email protected]/
Reported-by: [email protected]
Reviewed-by: Eric Biggers <[email protected]>
Signed-off-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
diff --git a/include/crypto/rng.h b/include/crypto/rng.h
index 8b4b844b..17bb3673 100644
--- a/include/crypto/rng.h
+++ b/include/crypto/rng.h
@@ -111,6 +111,8 @@ static inline struct rng_alg *crypto_rng_alg(struct crypto_rng *tfm)
/**
* crypto_free_rng() - zeroize and free RNG handle
* @tfm: cipher handle to be freed
+ *
+ * If @tfm is a NULL or error pointer, this function does nothing.
*/
static inline void crypto_free_rng(struct crypto_rng *tfm)
{
