From 83681f2bebb34dbb3f03fecd8f570308ab8b7c2c Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 2 Mar 2021 21:33:03 +0100 Subject: 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/000000000000de949705bc59e0f6@google.com/ Reported-by: syzbot+12cf5fbfdeba210a89dd@syzkaller.appspotmail.com Reviewed-by: Eric Biggers Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu --- include/crypto/hash.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/crypto/hash.h') 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) { -- cgit v1.2.3