From: Eric Biggers <ebiggers@xxxxxxxxxx> 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@xxxxxxxxxx> --- crypto/algapi.c | 8 ++++---- crypto/api.c | 2 +- crypto/crypto_user.c | 4 ++-- crypto/internal.h | 4 ++-- crypto/proc.c | 2 +- include/linux/crypto.h | 2 +- 6 files changed, 11 insertions(+), 11 deletions(-) diff --git a/crypto/algapi.c b/crypto/algapi.c index 60d7366ed343..8084a76e01d8 100644 --- a/crypto/algapi.c +++ b/crypto/algapi.c @@ -62,7 +62,7 @@ static int crypto_check_alg(struct crypto_alg *alg) if (alg->cra_priority < 0) return -EINVAL; - atomic_set(&alg->cra_refcnt, 1); + refcount_set(&alg->cra_refcnt, 1); return crypto_set_driver_name(alg); } @@ -224,7 +224,7 @@ static struct crypto_larval *__crypto_register_alg(struct crypto_alg *alg) if (!larval->adult) goto free_larval; - atomic_set(&larval->alg.cra_refcnt, 1); + refcount_set(&larval->alg.cra_refcnt, 1); memcpy(larval->alg.cra_driver_name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME); larval->alg.cra_priority = alg->cra_priority; @@ -399,7 +399,7 @@ int crypto_unregister_alg(struct crypto_alg *alg) if (ret) return ret; - BUG_ON(atomic_read(&alg->cra_refcnt) != 1); + BUG_ON(refcount_read(&alg->cra_refcnt) != 1); if (alg->cra_destroy) alg->cra_destroy(alg); @@ -490,7 +490,7 @@ void crypto_unregister_template(struct crypto_template *tmpl) up_write(&crypto_alg_sem); hlist_for_each_entry_safe(inst, n, list, list) { - BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1); + BUG_ON(refcount_read(&inst->alg.cra_refcnt) != 1); crypto_free_instance(inst); } crypto_remove_final(&users); diff --git a/crypto/api.c b/crypto/api.c index 6da802d7be67..70a894e52ff3 100644 --- a/crypto/api.c +++ b/crypto/api.c @@ -137,7 +137,7 @@ static struct crypto_alg *crypto_larval_add(const char *name, u32 type, if (IS_ERR(larval)) return ERR_CAST(larval); - atomic_set(&larval->alg.cra_refcnt, 2); + refcount_set(&larval->alg.cra_refcnt, 2); down_write(&crypto_alg_sem); alg = __crypto_alg_lookup(name, type, mask); diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c index 0dbe2be7f783..5c291eedaa70 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); diff --git a/crypto/internal.h b/crypto/internal.h index ae65e5fcaa59..1388af6da85a 100644 --- a/crypto/internal.h +++ b/crypto/internal.h @@ -105,13 +105,13 @@ int crypto_type_has_alg(const char *name, const struct crypto_type *frontend, static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg) { - atomic_inc(&alg->cra_refcnt); + refcount_inc(&alg->cra_refcnt); return alg; } static inline void crypto_alg_put(struct crypto_alg *alg) { - if (atomic_dec_and_test(&alg->cra_refcnt) && alg->cra_destroy) + if (refcount_dec_and_test(&alg->cra_refcnt) && alg->cra_destroy) alg->cra_destroy(alg); } diff --git a/crypto/proc.c b/crypto/proc.c index 2cc10c96d753..822fcef6d91c 100644 --- a/crypto/proc.c +++ b/crypto/proc.c @@ -46,7 +46,7 @@ static int c_show(struct seq_file *m, void *p) seq_printf(m, "driver : %s\n", alg->cra_driver_name); seq_printf(m, "module : %s\n", module_name(alg->cra_module)); seq_printf(m, "priority : %d\n", alg->cra_priority); - seq_printf(m, "refcnt : %d\n", atomic_read(&alg->cra_refcnt)); + seq_printf(m, "refcnt : %u\n", refcount_read(&alg->cra_refcnt)); seq_printf(m, "selftest : %s\n", (alg->cra_flags & CRYPTO_ALG_TESTED) ? "passed" : "unknown"); diff --git a/include/linux/crypto.h b/include/linux/crypto.h index 78508ca4b108..231e59f90d32 100644 --- a/include/linux/crypto.h +++ b/include/linux/crypto.h @@ -447,7 +447,7 @@ struct crypto_alg { unsigned int cra_alignmask; int cra_priority; - atomic_t cra_refcnt; + refcount_t cra_refcnt; char cra_name[CRYPTO_MAX_ALG_NAME]; char cra_driver_name[CRYPTO_MAX_ALG_NAME]; -- 2.15.1