crypto: algapi - convert cra_refcnt to refcount_t
Reference counters should use refcount_t rather than atomic_t, since the
refcount_t implementation can prevent overflows, reducing the
exploitability of reference leak bugs. crypto_alg.cra_refcount is a
reference counter with the usual semantics, so switch it over to
refcount_t.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c
index 0dbe2be7..5c291ee 100644
--- a/crypto/crypto_user.c
+++ b/crypto/crypto_user.c
@@ -169,7 +169,7 @@ static int crypto_report_one(struct crypto_alg *alg,
ualg->cru_type = 0;
ualg->cru_mask = 0;
ualg->cru_flags = alg->cra_flags;
- ualg->cru_refcnt = atomic_read(&alg->cra_refcnt);
+ ualg->cru_refcnt = refcount_read(&alg->cra_refcnt);
if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
goto nla_put_failure;
@@ -387,7 +387,7 @@ static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
goto drop_alg;
err = -EBUSY;
- if (atomic_read(&alg->cra_refcnt) > 2)
+ if (refcount_read(&alg->cra_refcnt) > 2)
goto drop_alg;
err = crypto_unregister_instance((struct crypto_instance *)alg);