From f7d76e05d058b832b373237566cc1af8251371b5 Mon Sep 17 00:00:00 2001 From: Corentin Labbe Date: Thu, 29 Nov 2018 14:42:21 +0000 Subject: crypto: user - fix use_after_free of struct xxx_request All crypto_stats functions use the struct xxx_request for feeding stats, but in some case this structure could already be freed. For fixing this, the needed parameters (len and alg) will be stored before the request being executed. Fixes: cac5818c25d0 ("crypto: user - Implement a generic crypto statistics") Reported-by: syzbot Signed-off-by: Corentin Labbe Signed-off-by: Herbert Xu --- include/crypto/rng.h | 27 +++------------------------ 1 file changed, 3 insertions(+), 24 deletions(-) (limited to 'include/crypto/rng.h') diff --git a/include/crypto/rng.h b/include/crypto/rng.h index 966615bba45e..022a1b896b47 100644 --- a/include/crypto/rng.h +++ b/include/crypto/rng.h @@ -122,29 +122,6 @@ static inline void crypto_free_rng(struct crypto_rng *tfm) crypto_destroy_tfm(tfm, crypto_rng_tfm(tfm)); } -static inline void crypto_stat_rng_seed(struct crypto_rng *tfm, int ret) -{ -#ifdef CONFIG_CRYPTO_STATS - if (ret && ret != -EINPROGRESS && ret != -EBUSY) - atomic64_inc(&tfm->base.__crt_alg->rng_err_cnt); - else - atomic64_inc(&tfm->base.__crt_alg->seed_cnt); -#endif -} - -static inline void crypto_stat_rng_generate(struct crypto_rng *tfm, - unsigned int dlen, int ret) -{ -#ifdef CONFIG_CRYPTO_STATS - if (ret && ret != -EINPROGRESS && ret != -EBUSY) { - atomic64_inc(&tfm->base.__crt_alg->rng_err_cnt); - } else { - atomic64_inc(&tfm->base.__crt_alg->generate_cnt); - atomic64_add(dlen, &tfm->base.__crt_alg->generate_tlen); - } -#endif -} - /** * crypto_rng_generate() - get random number * @tfm: cipher handle @@ -163,10 +140,12 @@ static inline int crypto_rng_generate(struct crypto_rng *tfm, const u8 *src, unsigned int slen, u8 *dst, unsigned int dlen) { + struct crypto_alg *alg = tfm->base.__crt_alg; int ret; + crypto_stats_get(alg); ret = crypto_rng_alg(tfm)->generate(tfm, src, slen, dst, dlen); - crypto_stat_rng_generate(tfm, dlen, ret); + crypto_stats_rng_generate(alg, dlen, ret); return ret; } -- cgit v1.2.3