diff mbox series

[v2] crypto: api - check for ERR pointers in crypto_destroy_tfm()

Message ID 20210302075530.29315-1-ardb@kernel.org
State Superseded
Headers show
Series [v2] crypto: api - check for ERR pointers in crypto_destroy_tfm() | expand

Commit Message

Ard Biesheuvel March 2, 2021, 7:55 a.m. UTC 
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
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
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      | 2 ++
 include/crypto/kpp.h       | 2 ++
 include/crypto/rng.h       | 2 ++
 include/crypto/skcipher.h  | 2 ++
 8 files changed, 15 insertions(+), 1 deletion(-)

Comments

Eric Biggers March 2, 2021, 5:39 p.m. UTC | #1 
On Tue, Mar 02, 2021 at 08:55:30AM +0100, Ard Biesheuvel wrote:
> diff --git a/include/crypto/hash.h b/include/crypto/hash.h

> index 13f8a6a54ca8..f065dbe2205c 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)

>  {


You missed crypto_free_shash().

Otherwise this looks good, feel free to add:

Reviewed-by: Eric Biggers <ebiggers@google.com>


- Eric
diff mbox series

Patch

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..f065dbe2205c 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)
 {
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)
 {