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/000000000000de949705bc59e0f6@xxxxxxxxxx/ Reported-by: syzbot+12cf5fbfdeba210a89dd@xxxxxxxxxxxxxxxxxxxxxxxxx Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx> Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> --- v3: missed crypto_free_shash() in v2 add Eric's Rb v2: update kerneldoc comments of callers to crypto_destroy_tfm() that NULL or error pointers are ignored. crypto/api.c | 2 +- include/crypto/acompress.h | 2 ++ include/crypto/aead.h | 2 ++ include/crypto/akcipher.h | 2 ++ include/crypto/hash.h | 4 ++++ include/crypto/kpp.h | 2 ++ include/crypto/rng.h | 2 ++ include/crypto/skcipher.h | 2 ++ 8 files changed, 17 insertions(+), 1 deletion(-) diff --git a/crypto/api.c b/crypto/api.c index ed08cbd5b9d3..c4eda56cff89 100644 --- a/crypto/api.c +++ b/crypto/api.c @@ -562,7 +562,7 @@ void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm) { struct crypto_alg *alg; - if (unlikely(!mem)) + if (IS_ERR_OR_NULL(mem)) return; alg = tfm->__crt_alg; diff --git a/include/crypto/acompress.h b/include/crypto/acompress.h index fcde59c65a81..cb3d6b1c655d 100644 --- a/include/crypto/acompress.h +++ b/include/crypto/acompress.h @@ -165,6 +165,8 @@ static inline struct crypto_acomp *crypto_acomp_reqtfm(struct acomp_req *req) * crypto_free_acomp() -- free ACOMPRESS tfm handle * * @tfm: ACOMPRESS tfm handle allocated with crypto_alloc_acomp() + * + * If @tfm is a NULL or error pointer, this function does nothing. */ static inline void crypto_free_acomp(struct crypto_acomp *tfm) { diff --git a/include/crypto/aead.h b/include/crypto/aead.h index fcc12c593ef8..e728469c4ccc 100644 --- a/include/crypto/aead.h +++ b/include/crypto/aead.h @@ -185,6 +185,8 @@ static inline struct crypto_tfm *crypto_aead_tfm(struct crypto_aead *tfm) /** * crypto_free_aead() - zeroize and free aead handle * @tfm: cipher handle to be freed + * + * If @tfm is a NULL or error pointer, this function does nothing. */ static inline void crypto_free_aead(struct crypto_aead *tfm) { diff --git a/include/crypto/akcipher.h b/include/crypto/akcipher.h index 1d3aa252caba..5764b46bd1ec 100644 --- a/include/crypto/akcipher.h +++ b/include/crypto/akcipher.h @@ -174,6 +174,8 @@ static inline struct crypto_akcipher *crypto_akcipher_reqtfm( * crypto_free_akcipher() - free AKCIPHER tfm handle * * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher() + * + * If @tfm is a NULL or error pointer, this function does nothing. */ static inline void crypto_free_akcipher(struct crypto_akcipher *tfm) { diff --git a/include/crypto/hash.h b/include/crypto/hash.h index 13f8a6a54ca8..b2bc1e46e86a 100644 --- a/include/crypto/hash.h +++ b/include/crypto/hash.h @@ -281,6 +281,8 @@ static inline struct crypto_tfm *crypto_ahash_tfm(struct crypto_ahash *tfm) /** * crypto_free_ahash() - zeroize and free the ahash handle * @tfm: cipher handle to be freed + * + * If @tfm is a NULL or error pointer, this function does nothing. */ static inline void crypto_free_ahash(struct crypto_ahash *tfm) { @@ -724,6 +726,8 @@ static inline struct crypto_tfm *crypto_shash_tfm(struct crypto_shash *tfm) /** * crypto_free_shash() - zeroize and free the message digest handle * @tfm: cipher handle to be freed + * + * If @tfm is a NULL or error pointer, this function does nothing. */ static inline void crypto_free_shash(struct crypto_shash *tfm) { diff --git a/include/crypto/kpp.h b/include/crypto/kpp.h index 88b591215d5c..cccceadc164b 100644 --- a/include/crypto/kpp.h +++ b/include/crypto/kpp.h @@ -154,6 +154,8 @@ static inline void crypto_kpp_set_flags(struct crypto_kpp *tfm, u32 flags) * crypto_free_kpp() - free KPP tfm handle * * @tfm: KPP tfm handle allocated with crypto_alloc_kpp() + * + * If @tfm is a NULL or error pointer, this function does nothing. */ static inline void crypto_free_kpp(struct crypto_kpp *tfm) { diff --git a/include/crypto/rng.h b/include/crypto/rng.h index 8b4b844b4eef..17bb3673d3c1 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) { diff --git a/include/crypto/skcipher.h b/include/crypto/skcipher.h index 6a733b171a5d..ef0fc9ed4342 100644 --- a/include/crypto/skcipher.h +++ b/include/crypto/skcipher.h @@ -196,6 +196,8 @@ static inline struct crypto_tfm *crypto_skcipher_tfm( /** * crypto_free_skcipher() - zeroize and free cipher handle * @tfm: cipher handle to be freed + * + * If @tfm is a NULL or error pointer, this function does nothing. */ static inline void crypto_free_skcipher(struct crypto_skcipher *tfm) { -- 2.30.1
