[PATCH] crypto: algif_hash - Allocate hash state with kmalloc

[PATCH] crypto: algif_hash - Allocate hash state with kmalloc

[Herbert Xu]

Allocating the hash state on the stack limits its size.  Change
this to use kmalloc so the limit can be removed for new drivers.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c
index 1d017ec5c63c..63af72e19fa8 100644
--- a/crypto/algif_hash.c
+++ b/crypto/algif_hash.c
@@ -235,24 +235,31 @@ static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
 	struct alg_sock *ask = alg_sk(sk);
 	struct hash_ctx *ctx = ask->private;
 	struct ahash_request *req = &ctx->req;
-	char state[HASH_MAX_STATESIZE];
+	struct crypto_ahash *tfm;
 	struct sock *sk2;
 	struct alg_sock *ask2;
 	struct hash_ctx *ctx2;
+	char *state;
 	bool more;
 	int err;
 
+	tfm = crypto_ahash_reqtfm(req);
+	state = kmalloc(crypto_ahash_statesize(tfm), GFP_KERNEL);
+	err = -ENOMEM;
+	if (!state)
+		goto out;
+
 	lock_sock(sk);
 	more = ctx->more;
 	err = more ? crypto_ahash_export(req, state) : 0;
 	release_sock(sk);
 
 	if (err)
-		return err;
+		goto out_free_state;
 
 	err = af_alg_accept(ask->parent, newsock, kern);
 	if (err)
-		return err;
+		goto out_free_state;
 
 	sk2 = newsock->sk;
 	ask2 = alg_sk(sk2);
@@ -260,7 +267,7 @@ static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
 	ctx2->more = more;
 
 	if (!more)
-		return err;
+		goto out_free_state;
 
 	err = crypto_ahash_import(&ctx2->req, state);
 	if (err) {
@@ -268,6 +275,10 @@ static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
 		sock_put(sk2);
 	}
 
+out_free_state:
+	kfree_sensitive(state);
+
+out:
 	return err;
 }
 
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

[PATCH] crypto: hash - Remove maximum statesize limit

[Herbert Xu]

Remove the HASH_MAX_STATESIZE limit now that it is unused.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/shash.c b/crypto/shash.c
index dcc6a7170ce4..4cefa614dbbd 100644
--- a/crypto/shash.c
+++ b/crypto/shash.c
@@ -569,8 +569,7 @@ int hash_prepare_alg(struct hash_alg_common *alg)
 	struct crypto_istat_hash *istat = hash_get_stat(alg);
 	struct crypto_alg *base = &alg->base;
 
-	if (alg->digestsize > HASH_MAX_DIGESTSIZE ||
-	    alg->statesize > HASH_MAX_STATESIZE)
+	if (alg->digestsize > HASH_MAX_DIGESTSIZE)
 		return -EINVAL;
 
 	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
diff --git a/include/crypto/hash.h b/include/crypto/hash.h
index 1ed674ba8429..3a04e601ad6a 100644
--- a/include/crypto/hash.h
+++ b/include/crypto/hash.h
@@ -183,8 +183,6 @@ struct shash_desc {
  */
 #define HASH_MAX_DESCSIZE	(sizeof(struct shash_desc) + 360)
 
-#define HASH_MAX_STATESIZE	512
-
 #define SHASH_DESC_ON_STACK(shash, ctx)					     \
 	char __##shash##_desc[sizeof(struct shash_desc) + HASH_MAX_DESCSIZE] \
 		__aligned(__alignof__(struct shash_desc));		     \
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [PATCH] crypto: algif_hash - Allocate hash state with kmalloc

[Ondrej Mosnáček]

On Tue, Mar 28, 2023 at 5:58 AM Herbert Xu <herbert@gondor.apana.org.au> wrote:
>
> Allocating the hash state on the stack limits its size.  Change
> this to use kmalloc so the limit can be removed for new drivers.
>
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
>
> diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c
> index 1d017ec5c63c..63af72e19fa8 100644
> --- a/crypto/algif_hash.c
> +++ b/crypto/algif_hash.c
> @@ -235,24 +235,31 @@ static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
>         struct alg_sock *ask = alg_sk(sk);
>         struct hash_ctx *ctx = ask->private;
>         struct ahash_request *req = &ctx->req;
> -       char state[HASH_MAX_STATESIZE];
> +       struct crypto_ahash *tfm;
>         struct sock *sk2;
>         struct alg_sock *ask2;
>         struct hash_ctx *ctx2;
> +       char *state;
>         bool more;
>         int err;
>
> +       tfm = crypto_ahash_reqtfm(req);
> +       state = kmalloc(crypto_ahash_statesize(tfm), GFP_KERNEL);

Shouldn't sock_kmalloc() be used instead?

> +       err = -ENOMEM;
> +       if (!state)
> +               goto out;
> +
>         lock_sock(sk);
>         more = ctx->more;
>         err = more ? crypto_ahash_export(req, state) : 0;
>         release_sock(sk);
>
>         if (err)
> -               return err;
> +               goto out_free_state;
>
>         err = af_alg_accept(ask->parent, newsock, kern);
>         if (err)
> -               return err;
> +               goto out_free_state;
>
>         sk2 = newsock->sk;
>         ask2 = alg_sk(sk2);
> @@ -260,7 +267,7 @@ static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
>         ctx2->more = more;
>
>         if (!more)
> -               return err;
> +               goto out_free_state;
>
>         err = crypto_ahash_import(&ctx2->req, state);
>         if (err) {
> @@ -268,6 +275,10 @@ static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
>                 sock_put(sk2);
>         }
>
> +out_free_state:
> +       kfree_sensitive(state);
> +
> +out:
>         return err;
>  }
>
> --
> Email: Herbert Xu <herbert@gondor.apana.org.au>
> Home Page: http://gondor.apana.org.au/~herbert/
> PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [PATCH] crypto: algif_hash - Allocate hash state with kmalloc

[Herbert Xu]

On Tue, Mar 28, 2023 at 01:01:01PM +0200, Ondrej Mosnáček wrote:
>
> Shouldn't sock_kmalloc() be used instead?

Thanks for the review!

No that isn't necessary because this is transient and not really
open to abuse by the user.

Cheers,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [PATCH] crypto: hash - Remove maximum statesize limit

[Thomas BOURGOIN]

Hi herbert,

I'm testing the serie on STM32MP1.
I cannot apply the patch on my kernel tree.
The patch fails to apply for the file crypto/ahash.c
I tried on tags v6.3-rc1 ans v6.3-p2.

On which branch can I test your patch ?

I see the overall idea of the patch so I modified crypto/ahash.c
and the serie works on STM32MP1.

Thomas

Re: [PATCH] crypto: hash - Remove maximum statesize limit

[Herbert Xu]

On Wed, Mar 29, 2023 at 05:26:29PM +0200, Thomas BOURGOIN wrote:
> Hi herbert,
> 
> I'm testing the serie on STM32MP1.
> I cannot apply the patch on my kernel tree.
> The patch fails to apply for the file crypto/ahash.c
> I tried on tags v6.3-rc1 ans v6.3-p2.
> 
> On which branch can I test your patch ?

Please use the cryptodev tree for all crypto work.

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [PATCH] crypto: hash - Remove maximum statesize limit

[kernel test robot]

Hi Herbert,

I love your patch! Perhaps something to improve:

[auto build test WARNING on herbert-cryptodev-2.6/master]
[also build test WARNING on next-20230331]
[cannot apply to herbert-crypto-2.6/master linus/master v6.3-rc4]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Herbert-Xu/crypto-hash-Remove-maximum-statesize-limit/20230328-115842
base:   https://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git master
patch link:    https://lore.kernel.org/r/ZCJllZQBWfjMCaoQ%40gondor.apana.org.au
patch subject: [PATCH] crypto: hash - Remove maximum statesize limit
config: x86_64-rhel-8.3 (https://download.01.org/0day-ci/archive/20230331/202303312021.84WtsA4u-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/5258657ff30097b887ac972b95a5563918f4448f
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Herbert-Xu/crypto-hash-Remove-maximum-statesize-limit/20230328-115842
        git checkout 5258657ff30097b887ac972b95a5563918f4448f
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202303312021.84WtsA4u-lkp@intel.com/

All warnings (new ones prefixed by >>):

   crypto/algif_hash.c: In function 'hash_accept':
   crypto/algif_hash.c:238:20: error: 'HASH_MAX_STATESIZE' undeclared (first use in this function); did you mean 'HASH_MAX_DESCSIZE'?
     238 |         char state[HASH_MAX_STATESIZE];
         |                    ^~~~~~~~~~~~~~~~~~
         |                    HASH_MAX_DESCSIZE
   crypto/algif_hash.c:238:20: note: each undeclared identifier is reported only once for each function it appears in
>> crypto/algif_hash.c:238:14: warning: unused variable 'state' [-Wunused-variable]
     238 |         char state[HASH_MAX_STATESIZE];
         |              ^~~~~


vim +/state +238 crypto/algif_hash.c

fe869cdb89c95d0 Herbert Xu    2010-10-19  230  
cdfbabfb2f0ce98 David Howells 2017-03-09  231  static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
cdfbabfb2f0ce98 David Howells 2017-03-09  232  		       bool kern)
fe869cdb89c95d0 Herbert Xu    2010-10-19  233  {
fe869cdb89c95d0 Herbert Xu    2010-10-19  234  	struct sock *sk = sock->sk;
fe869cdb89c95d0 Herbert Xu    2010-10-19  235  	struct alg_sock *ask = alg_sk(sk);
fe869cdb89c95d0 Herbert Xu    2010-10-19  236  	struct hash_ctx *ctx = ask->private;
fe869cdb89c95d0 Herbert Xu    2010-10-19  237  	struct ahash_request *req = &ctx->req;
b68a7ec1e9a3efa Kees Cook     2018-08-07 @238  	char state[HASH_MAX_STATESIZE];
fe869cdb89c95d0 Herbert Xu    2010-10-19  239  	struct sock *sk2;
fe869cdb89c95d0 Herbert Xu    2010-10-19  240  	struct alg_sock *ask2;
fe869cdb89c95d0 Herbert Xu    2010-10-19  241  	struct hash_ctx *ctx2;
4afa5f961792745 Herbert Xu    2015-11-01  242  	bool more;
fe869cdb89c95d0 Herbert Xu    2010-10-19  243  	int err;
fe869cdb89c95d0 Herbert Xu    2010-10-19  244  
4afa5f961792745 Herbert Xu    2015-11-01  245  	lock_sock(sk);
4afa5f961792745 Herbert Xu    2015-11-01  246  	more = ctx->more;
4afa5f961792745 Herbert Xu    2015-11-01  247  	err = more ? crypto_ahash_export(req, state) : 0;
4afa5f961792745 Herbert Xu    2015-11-01  248  	release_sock(sk);
4afa5f961792745 Herbert Xu    2015-11-01  249  
fe869cdb89c95d0 Herbert Xu    2010-10-19  250  	if (err)
fe869cdb89c95d0 Herbert Xu    2010-10-19  251  		return err;
fe869cdb89c95d0 Herbert Xu    2010-10-19  252  
cdfbabfb2f0ce98 David Howells 2017-03-09  253  	err = af_alg_accept(ask->parent, newsock, kern);
fe869cdb89c95d0 Herbert Xu    2010-10-19  254  	if (err)
fe869cdb89c95d0 Herbert Xu    2010-10-19  255  		return err;
fe869cdb89c95d0 Herbert Xu    2010-10-19  256  
fe869cdb89c95d0 Herbert Xu    2010-10-19  257  	sk2 = newsock->sk;
fe869cdb89c95d0 Herbert Xu    2010-10-19  258  	ask2 = alg_sk(sk2);
fe869cdb89c95d0 Herbert Xu    2010-10-19  259  	ctx2 = ask2->private;
4afa5f961792745 Herbert Xu    2015-11-01  260  	ctx2->more = more;
4afa5f961792745 Herbert Xu    2015-11-01  261  
4afa5f961792745 Herbert Xu    2015-11-01  262  	if (!more)
4afa5f961792745 Herbert Xu    2015-11-01  263  		return err;
fe869cdb89c95d0 Herbert Xu    2010-10-19  264  
fe869cdb89c95d0 Herbert Xu    2010-10-19  265  	err = crypto_ahash_import(&ctx2->req, state);
fe869cdb89c95d0 Herbert Xu    2010-10-19  266  	if (err) {
fe869cdb89c95d0 Herbert Xu    2010-10-19  267  		sock_orphan(sk2);
fe869cdb89c95d0 Herbert Xu    2010-10-19  268  		sock_put(sk2);
fe869cdb89c95d0 Herbert Xu    2010-10-19  269  	}
fe869cdb89c95d0 Herbert Xu    2010-10-19  270  
fe869cdb89c95d0 Herbert Xu    2010-10-19  271  	return err;
fe869cdb89c95d0 Herbert Xu    2010-10-19  272  }
fe869cdb89c95d0 Herbert Xu    2010-10-19  273  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests

Re: [PATCH] crypto: hash - Remove maximum statesize limit

[kernel test robot]

Hi Herbert,

I love your patch! Yet something to improve:

[auto build test ERROR on herbert-cryptodev-2.6/master]
[also build test ERROR on next-20230331]
[cannot apply to herbert-crypto-2.6/master linus/master v6.3-rc4]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Herbert-Xu/crypto-hash-Remove-maximum-statesize-limit/20230328-115842
base:   https://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git master
patch link:    https://lore.kernel.org/r/ZCJllZQBWfjMCaoQ%40gondor.apana.org.au
patch subject: [PATCH] crypto: hash - Remove maximum statesize limit
config: x86_64-rhel-8.3-func (https://download.01.org/0day-ci/archive/20230402/202304020900.MhnE9RIZ-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/5258657ff30097b887ac972b95a5563918f4448f
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Herbert-Xu/crypto-hash-Remove-maximum-statesize-limit/20230328-115842
        git checkout 5258657ff30097b887ac972b95a5563918f4448f
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304020900.MhnE9RIZ-lkp@intel.com/

All errors (new ones prefixed by >>):

   crypto/algif_hash.c: In function 'hash_accept':
>> crypto/algif_hash.c:238:20: error: 'HASH_MAX_STATESIZE' undeclared (first use in this function); did you mean 'HASH_MAX_DESCSIZE'?
     238 |         char state[HASH_MAX_STATESIZE];
         |                    ^~~~~~~~~~~~~~~~~~
         |                    HASH_MAX_DESCSIZE
   crypto/algif_hash.c:238:20: note: each undeclared identifier is reported only once for each function it appears in
   crypto/algif_hash.c:238:14: warning: unused variable 'state' [-Wunused-variable]
     238 |         char state[HASH_MAX_STATESIZE];
         |              ^~~~~


vim +238 crypto/algif_hash.c

fe869cdb89c95d Herbert Xu    2010-10-19  230  
cdfbabfb2f0ce9 David Howells 2017-03-09  231  static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
cdfbabfb2f0ce9 David Howells 2017-03-09  232  		       bool kern)
fe869cdb89c95d Herbert Xu    2010-10-19  233  {
fe869cdb89c95d Herbert Xu    2010-10-19  234  	struct sock *sk = sock->sk;
fe869cdb89c95d Herbert Xu    2010-10-19  235  	struct alg_sock *ask = alg_sk(sk);
fe869cdb89c95d Herbert Xu    2010-10-19  236  	struct hash_ctx *ctx = ask->private;
fe869cdb89c95d Herbert Xu    2010-10-19  237  	struct ahash_request *req = &ctx->req;
b68a7ec1e9a3ef Kees Cook     2018-08-07 @238  	char state[HASH_MAX_STATESIZE];
fe869cdb89c95d Herbert Xu    2010-10-19  239  	struct sock *sk2;
fe869cdb89c95d Herbert Xu    2010-10-19  240  	struct alg_sock *ask2;
fe869cdb89c95d Herbert Xu    2010-10-19  241  	struct hash_ctx *ctx2;
4afa5f96179274 Herbert Xu    2015-11-01  242  	bool more;
fe869cdb89c95d Herbert Xu    2010-10-19  243  	int err;
fe869cdb89c95d Herbert Xu    2010-10-19  244  
4afa5f96179274 Herbert Xu    2015-11-01  245  	lock_sock(sk);
4afa5f96179274 Herbert Xu    2015-11-01  246  	more = ctx->more;
4afa5f96179274 Herbert Xu    2015-11-01  247  	err = more ? crypto_ahash_export(req, state) : 0;
4afa5f96179274 Herbert Xu    2015-11-01  248  	release_sock(sk);
4afa5f96179274 Herbert Xu    2015-11-01  249  
fe869cdb89c95d Herbert Xu    2010-10-19  250  	if (err)
fe869cdb89c95d Herbert Xu    2010-10-19  251  		return err;
fe869cdb89c95d Herbert Xu    2010-10-19  252  
cdfbabfb2f0ce9 David Howells 2017-03-09  253  	err = af_alg_accept(ask->parent, newsock, kern);
fe869cdb89c95d Herbert Xu    2010-10-19  254  	if (err)
fe869cdb89c95d Herbert Xu    2010-10-19  255  		return err;
fe869cdb89c95d Herbert Xu    2010-10-19  256  
fe869cdb89c95d Herbert Xu    2010-10-19  257  	sk2 = newsock->sk;
fe869cdb89c95d Herbert Xu    2010-10-19  258  	ask2 = alg_sk(sk2);
fe869cdb89c95d Herbert Xu    2010-10-19  259  	ctx2 = ask2->private;
4afa5f96179274 Herbert Xu    2015-11-01  260  	ctx2->more = more;
4afa5f96179274 Herbert Xu    2015-11-01  261  
4afa5f96179274 Herbert Xu    2015-11-01  262  	if (!more)
4afa5f96179274 Herbert Xu    2015-11-01  263  		return err;
fe869cdb89c95d Herbert Xu    2010-10-19  264  
fe869cdb89c95d Herbert Xu    2010-10-19  265  	err = crypto_ahash_import(&ctx2->req, state);
fe869cdb89c95d Herbert Xu    2010-10-19  266  	if (err) {
fe869cdb89c95d Herbert Xu    2010-10-19  267  		sock_orphan(sk2);
fe869cdb89c95d Herbert Xu    2010-10-19  268  		sock_put(sk2);
fe869cdb89c95d Herbert Xu    2010-10-19  269  	}
fe869cdb89c95d Herbert Xu    2010-10-19  270  
fe869cdb89c95d Herbert Xu    2010-10-19  271  	return err;
fe869cdb89c95d Herbert Xu    2010-10-19  272  }
fe869cdb89c95d Herbert Xu    2010-10-19  273  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests

Re: [PATCH] crypto: hash - Remove maximum statesize limit

[Thomas BOURGOIN]

> Please use the cryptodev tree for all crypto work.

Thanks for the tip, the serie works on STM32MP1

Tested-by : Thomas Bourgoin <thomas.bourgoin@foss.st.com>

BR