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* [PATCH] KEYS: trusted: fix a couple error pointer dereferences
@ 2021-04-14  6:08 Dan Carpenter
  2021-04-14 14:07 ` Serge E. Hallyn
  2021-04-16 12:42 ` Sumit Garg
  0 siblings, 2 replies; 5+ messages in thread
From: Dan Carpenter @ 2021-04-14  6:08 UTC (permalink / raw)
  To: Sumit Garg
  Cc: James Bottomley, Jarkko Sakkinen, Mimi Zohar, David Howells,
	James Morris, Serge E. Hallyn, linux-integrity, keyrings,
	linux-security-module, kernel-janitors

If registering "reg_shm_out" fails, then it is an error pointer and the
error handling will call tee_shm_free(reg_shm_out) which leads to an
error pointer dereference and an Oops.

I've re-arranged it so we only free things that have been allocated
successfully.

Fixes: 6dd95e650c8a ("KEYS: trusted: Introduce TEE based Trusted Keys")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 security/keys/trusted-keys/trusted_tee.c | 24 ++++++++++--------------
 1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c
index 2ce66c199e1d..45f96f6ed673 100644
--- a/security/keys/trusted-keys/trusted_tee.c
+++ b/security/keys/trusted-keys/trusted_tee.c
@@ -65,7 +65,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob)
 	int ret;
 	struct tee_ioctl_invoke_arg inv_arg;
 	struct tee_param param[4];
-	struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL;
+	struct tee_shm *reg_shm_in, *reg_shm_out;
 
 	memset(&inv_arg, 0, sizeof(inv_arg));
 	memset(&param, 0, sizeof(param));
@@ -84,7 +84,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob)
 	if (IS_ERR(reg_shm_out)) {
 		dev_err(pvt_data.dev, "blob shm register failed\n");
 		ret = PTR_ERR(reg_shm_out);
-		goto out;
+		goto free_shm_in;
 	}
 
 	inv_arg.func = TA_CMD_SEAL;
@@ -109,11 +109,9 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob)
 		p->blob_len = param[1].u.memref.size;
 	}
 
-out:
-	if (reg_shm_out)
-		tee_shm_free(reg_shm_out);
-	if (reg_shm_in)
-		tee_shm_free(reg_shm_in);
+	tee_shm_free(reg_shm_out);
+free_shm_in:
+	tee_shm_free(reg_shm_in);
 
 	return ret;
 }
@@ -126,7 +124,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob)
 	int ret;
 	struct tee_ioctl_invoke_arg inv_arg;
 	struct tee_param param[4];
-	struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL;
+	struct tee_shm *reg_shm_in, *reg_shm_out;
 
 	memset(&inv_arg, 0, sizeof(inv_arg));
 	memset(&param, 0, sizeof(param));
@@ -145,7 +143,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob)
 	if (IS_ERR(reg_shm_out)) {
 		dev_err(pvt_data.dev, "key shm register failed\n");
 		ret = PTR_ERR(reg_shm_out);
-		goto out;
+		goto free_shm_in;
 	}
 
 	inv_arg.func = TA_CMD_UNSEAL;
@@ -170,11 +168,9 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob)
 		p->key_len = param[1].u.memref.size;
 	}
 
-out:
-	if (reg_shm_out)
-		tee_shm_free(reg_shm_out);
-	if (reg_shm_in)
-		tee_shm_free(reg_shm_in);
+	tee_shm_free(reg_shm_out);
+free_shm_in:
+	tee_shm_free(reg_shm_in);
 
 	return ret;
 }
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH] KEYS: trusted: fix a couple error pointer dereferences
  2021-04-14  6:08 [PATCH] KEYS: trusted: fix a couple error pointer dereferences Dan Carpenter
@ 2021-04-14 14:07 ` Serge E. Hallyn
  2021-04-16 12:45   ` Sumit Garg
  2021-04-16 12:42 ` Sumit Garg
  1 sibling, 1 reply; 5+ messages in thread
From: Serge E. Hallyn @ 2021-04-14 14:07 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: Sumit Garg, James Bottomley, Jarkko Sakkinen, Mimi Zohar,
	David Howells, James Morris, Serge E. Hallyn, linux-integrity,
	keyrings, linux-security-module, kernel-janitors

On Wed, Apr 14, 2021 at 09:08:58AM +0300, Dan Carpenter wrote:
> If registering "reg_shm_out" fails, then it is an error pointer and the
> error handling will call tee_shm_free(reg_shm_out) which leads to an
> error pointer dereference and an Oops.
> 
> I've re-arranged it so we only free things that have been allocated
> successfully.
> 
> Fixes: 6dd95e650c8a ("KEYS: trusted: Introduce TEE based Trusted Keys")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
>  security/keys/trusted-keys/trusted_tee.c | 24 ++++++++++--------------
>  1 file changed, 10 insertions(+), 14 deletions(-)
> 
> diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c
> index 2ce66c199e1d..45f96f6ed673 100644
> --- a/security/keys/trusted-keys/trusted_tee.c
> +++ b/security/keys/trusted-keys/trusted_tee.c
> @@ -65,7 +65,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob)
>  	int ret;
>  	struct tee_ioctl_invoke_arg inv_arg;
>  	struct tee_param param[4];
> -	struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL;
> +	struct tee_shm *reg_shm_in, *reg_shm_out;

I don't have this file (trusted_tee.c) in my tree and there's no lore
link here to previous what threads this depends on.  Based on the
context I can't verify that reg_shm_in will always be initialized
before you get to the free_shm_in label.

>  
>  	memset(&inv_arg, 0, sizeof(inv_arg));
>  	memset(&param, 0, sizeof(param));
> @@ -84,7 +84,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob)
>  	if (IS_ERR(reg_shm_out)) {
>  		dev_err(pvt_data.dev, "blob shm register failed\n");
>  		ret = PTR_ERR(reg_shm_out);
> -		goto out;
> +		goto free_shm_in;
>  	}
>  
>  	inv_arg.func = TA_CMD_SEAL;
> @@ -109,11 +109,9 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob)
>  		p->blob_len = param[1].u.memref.size;
>  	}
>  
> -out:
> -	if (reg_shm_out)
> -		tee_shm_free(reg_shm_out);
> -	if (reg_shm_in)
> -		tee_shm_free(reg_shm_in);
> +	tee_shm_free(reg_shm_out);
> +free_shm_in:
> +	tee_shm_free(reg_shm_in);
>  
>  	return ret;
>  }
> @@ -126,7 +124,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob)
>  	int ret;
>  	struct tee_ioctl_invoke_arg inv_arg;
>  	struct tee_param param[4];
> -	struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL;
> +	struct tee_shm *reg_shm_in, *reg_shm_out;
>  
>  	memset(&inv_arg, 0, sizeof(inv_arg));
>  	memset(&param, 0, sizeof(param));
> @@ -145,7 +143,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob)
>  	if (IS_ERR(reg_shm_out)) {
>  		dev_err(pvt_data.dev, "key shm register failed\n");
>  		ret = PTR_ERR(reg_shm_out);
> -		goto out;
> +		goto free_shm_in;
>  	}
>  
>  	inv_arg.func = TA_CMD_UNSEAL;
> @@ -170,11 +168,9 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob)
>  		p->key_len = param[1].u.memref.size;
>  	}
>  
> -out:
> -	if (reg_shm_out)
> -		tee_shm_free(reg_shm_out);
> -	if (reg_shm_in)
> -		tee_shm_free(reg_shm_in);
> +	tee_shm_free(reg_shm_out);
> +free_shm_in:
> +	tee_shm_free(reg_shm_in);
>  
>  	return ret;
>  }
> -- 
> 2.30.2

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] KEYS: trusted: fix a couple error pointer dereferences
  2021-04-14  6:08 [PATCH] KEYS: trusted: fix a couple error pointer dereferences Dan Carpenter
  2021-04-14 14:07 ` Serge E. Hallyn
@ 2021-04-16 12:42 ` Sumit Garg
  1 sibling, 0 replies; 5+ messages in thread
From: Sumit Garg @ 2021-04-16 12:42 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: James Bottomley, Jarkko Sakkinen, Mimi Zohar, David Howells,
	James Morris, Serge E. Hallyn, linux-integrity,
	open list:ASYMMETRIC KEYS, open list:SECURITY SUBSYSTEM,
	kernel-janitors

Hi Dan,

On Wed, 14 Apr 2021 at 11:39, Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> If registering "reg_shm_out" fails, then it is an error pointer and the
> error handling will call tee_shm_free(reg_shm_out) which leads to an
> error pointer dereference and an Oops.
>
> I've re-arranged it so we only free things that have been allocated
> successfully.
>
> Fixes: 6dd95e650c8a ("KEYS: trusted: Introduce TEE based Trusted Keys")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
>  security/keys/trusted-keys/trusted_tee.c | 24 ++++++++++--------------
>  1 file changed, 10 insertions(+), 14 deletions(-)
>

Thanks for fixing the error path. Although an alternative simple fix
could be [1] but I liked your approach to get rid of redundant "if"
checks. FWIW:

Reviewed-by: Sumit Garg <sumit.garg@linaro.org>

[1]

diff --git a/security/keys/trusted-keys/trusted_tee.c
b/security/keys/trusted-keys/trusted_tee.c
index 2ce66c199e1d..c4a54b0fa3eb 100644
--- a/security/keys/trusted-keys/trusted_tee.c
+++ b/security/keys/trusted-keys/trusted_tee.c
@@ -84,6 +84,7 @@ static int trusted_tee_seal(struct
trusted_key_payload *p, char *datablob)
        if (IS_ERR(reg_shm_out)) {
                dev_err(pvt_data.dev, "blob shm register failed\n");
                ret = PTR_ERR(reg_shm_out);
+               reg_shm_out = NULL;
                goto out;
        }

@@ -145,6 +146,7 @@ static int trusted_tee_unseal(struct
trusted_key_payload *p, char *datablob)
        if (IS_ERR(reg_shm_out)) {
                dev_err(pvt_data.dev, "key shm register failed\n");
                ret = PTR_ERR(reg_shm_out);
+               reg_shm_out = NULL;
                goto out;
        }

-Sumit

> diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c
> index 2ce66c199e1d..45f96f6ed673 100644
> --- a/security/keys/trusted-keys/trusted_tee.c
> +++ b/security/keys/trusted-keys/trusted_tee.c
> @@ -65,7 +65,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob)
>         int ret;
>         struct tee_ioctl_invoke_arg inv_arg;
>         struct tee_param param[4];
> -       struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL;
> +       struct tee_shm *reg_shm_in, *reg_shm_out;
>
>         memset(&inv_arg, 0, sizeof(inv_arg));
>         memset(&param, 0, sizeof(param));
> @@ -84,7 +84,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob)
>         if (IS_ERR(reg_shm_out)) {
>                 dev_err(pvt_data.dev, "blob shm register failed\n");
>                 ret = PTR_ERR(reg_shm_out);
> -               goto out;
> +               goto free_shm_in;
>         }
>
>         inv_arg.func = TA_CMD_SEAL;
> @@ -109,11 +109,9 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob)
>                 p->blob_len = param[1].u.memref.size;
>         }
>
> -out:
> -       if (reg_shm_out)
> -               tee_shm_free(reg_shm_out);
> -       if (reg_shm_in)
> -               tee_shm_free(reg_shm_in);
> +       tee_shm_free(reg_shm_out);
> +free_shm_in:
> +       tee_shm_free(reg_shm_in);
>
>         return ret;
>  }
> @@ -126,7 +124,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob)
>         int ret;
>         struct tee_ioctl_invoke_arg inv_arg;
>         struct tee_param param[4];
> -       struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL;
> +       struct tee_shm *reg_shm_in, *reg_shm_out;
>
>         memset(&inv_arg, 0, sizeof(inv_arg));
>         memset(&param, 0, sizeof(param));
> @@ -145,7 +143,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob)
>         if (IS_ERR(reg_shm_out)) {
>                 dev_err(pvt_data.dev, "key shm register failed\n");
>                 ret = PTR_ERR(reg_shm_out);
> -               goto out;
> +               goto free_shm_in;
>         }
>
>         inv_arg.func = TA_CMD_UNSEAL;
> @@ -170,11 +168,9 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob)
>                 p->key_len = param[1].u.memref.size;
>         }
>
> -out:
> -       if (reg_shm_out)
> -               tee_shm_free(reg_shm_out);
> -       if (reg_shm_in)
> -               tee_shm_free(reg_shm_in);
> +       tee_shm_free(reg_shm_out);
> +free_shm_in:
> +       tee_shm_free(reg_shm_in);
>
>         return ret;
>  }
> --
> 2.30.2
>

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH] KEYS: trusted: fix a couple error pointer dereferences
  2021-04-14 14:07 ` Serge E. Hallyn
@ 2021-04-16 12:45   ` Sumit Garg
  2021-04-16 14:08     ` Serge E. Hallyn
  0 siblings, 1 reply; 5+ messages in thread
From: Sumit Garg @ 2021-04-16 12:45 UTC (permalink / raw)
  To: Serge E. Hallyn
  Cc: Dan Carpenter, James Bottomley, Jarkko Sakkinen, Mimi Zohar,
	David Howells, James Morris, linux-integrity,
	open list:ASYMMETRIC KEYS, open list:SECURITY SUBSYSTEM,
	kernel-janitors

Hi Serge,

On Wed, 14 Apr 2021 at 19:37, Serge E. Hallyn <serge@hallyn.com> wrote:
>
> On Wed, Apr 14, 2021 at 09:08:58AM +0300, Dan Carpenter wrote:
> > If registering "reg_shm_out" fails, then it is an error pointer and the
> > error handling will call tee_shm_free(reg_shm_out) which leads to an
> > error pointer dereference and an Oops.
> >
> > I've re-arranged it so we only free things that have been allocated
> > successfully.
> >
> > Fixes: 6dd95e650c8a ("KEYS: trusted: Introduce TEE based Trusted Keys")
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > ---
> >  security/keys/trusted-keys/trusted_tee.c | 24 ++++++++++--------------
> >  1 file changed, 10 insertions(+), 14 deletions(-)
> >
> > diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c
> > index 2ce66c199e1d..45f96f6ed673 100644
> > --- a/security/keys/trusted-keys/trusted_tee.c
> > +++ b/security/keys/trusted-keys/trusted_tee.c
> > @@ -65,7 +65,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob)
> >       int ret;
> >       struct tee_ioctl_invoke_arg inv_arg;
> >       struct tee_param param[4];
> > -     struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL;
> > +     struct tee_shm *reg_shm_in, *reg_shm_out;
>
> I don't have this file (trusted_tee.c) in my tree and there's no lore
> link here to previous what threads this depends on.  Based on the
> context I can't verify that reg_shm_in will always be initialized
> before you get to the free_shm_in label.
>

You can find trusted_tee.c here [1].

[1] https://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd.git/tree/security/keys/trusted-keys/trusted_tee.c

-Sumit

> >
> >       memset(&inv_arg, 0, sizeof(inv_arg));
> >       memset(&param, 0, sizeof(param));
> > @@ -84,7 +84,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob)
> >       if (IS_ERR(reg_shm_out)) {
> >               dev_err(pvt_data.dev, "blob shm register failed\n");
> >               ret = PTR_ERR(reg_shm_out);
> > -             goto out;
> > +             goto free_shm_in;
> >       }
> >
> >       inv_arg.func = TA_CMD_SEAL;
> > @@ -109,11 +109,9 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob)
> >               p->blob_len = param[1].u.memref.size;
> >       }
> >
> > -out:
> > -     if (reg_shm_out)
> > -             tee_shm_free(reg_shm_out);
> > -     if (reg_shm_in)
> > -             tee_shm_free(reg_shm_in);
> > +     tee_shm_free(reg_shm_out);
> > +free_shm_in:
> > +     tee_shm_free(reg_shm_in);
> >
> >       return ret;
> >  }
> > @@ -126,7 +124,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob)
> >       int ret;
> >       struct tee_ioctl_invoke_arg inv_arg;
> >       struct tee_param param[4];
> > -     struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL;
> > +     struct tee_shm *reg_shm_in, *reg_shm_out;
> >
> >       memset(&inv_arg, 0, sizeof(inv_arg));
> >       memset(&param, 0, sizeof(param));
> > @@ -145,7 +143,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob)
> >       if (IS_ERR(reg_shm_out)) {
> >               dev_err(pvt_data.dev, "key shm register failed\n");
> >               ret = PTR_ERR(reg_shm_out);
> > -             goto out;
> > +             goto free_shm_in;
> >       }
> >
> >       inv_arg.func = TA_CMD_UNSEAL;
> > @@ -170,11 +168,9 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob)
> >               p->key_len = param[1].u.memref.size;
> >       }
> >
> > -out:
> > -     if (reg_shm_out)
> > -             tee_shm_free(reg_shm_out);
> > -     if (reg_shm_in)
> > -             tee_shm_free(reg_shm_in);
> > +     tee_shm_free(reg_shm_out);
> > +free_shm_in:
> > +     tee_shm_free(reg_shm_in);
> >
> >       return ret;
> >  }
> > --
> > 2.30.2

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] KEYS: trusted: fix a couple error pointer dereferences
  2021-04-16 12:45   ` Sumit Garg
@ 2021-04-16 14:08     ` Serge E. Hallyn
  0 siblings, 0 replies; 5+ messages in thread
From: Serge E. Hallyn @ 2021-04-16 14:08 UTC (permalink / raw)
  To: Sumit Garg
  Cc: Serge E. Hallyn, Dan Carpenter, James Bottomley, Jarkko Sakkinen,
	Mimi Zohar, David Howells, James Morris, linux-integrity,
	open list:ASYMMETRIC KEYS, open list:SECURITY SUBSYSTEM,
	kernel-janitors

On Fri, Apr 16, 2021 at 06:15:58PM +0530, Sumit Garg wrote:
> Hi Serge,
> 
> On Wed, 14 Apr 2021 at 19:37, Serge E. Hallyn <serge@hallyn.com> wrote:
> >
> > On Wed, Apr 14, 2021 at 09:08:58AM +0300, Dan Carpenter wrote:
> > > If registering "reg_shm_out" fails, then it is an error pointer and the
> > > error handling will call tee_shm_free(reg_shm_out) which leads to an
> > > error pointer dereference and an Oops.
> > >
> > > I've re-arranged it so we only free things that have been allocated
> > > successfully.
> > >
> > > Fixes: 6dd95e650c8a ("KEYS: trusted: Introduce TEE based Trusted Keys")
> > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > > ---
> > >  security/keys/trusted-keys/trusted_tee.c | 24 ++++++++++--------------
> > >  1 file changed, 10 insertions(+), 14 deletions(-)
> > >
> > > diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c
> > > index 2ce66c199e1d..45f96f6ed673 100644
> > > --- a/security/keys/trusted-keys/trusted_tee.c
> > > +++ b/security/keys/trusted-keys/trusted_tee.c
> > > @@ -65,7 +65,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob)
> > >       int ret;
> > >       struct tee_ioctl_invoke_arg inv_arg;
> > >       struct tee_param param[4];
> > > -     struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL;
> > > +     struct tee_shm *reg_shm_in, *reg_shm_out;
> >
> > I don't have this file (trusted_tee.c) in my tree and there's no lore
> > link here to previous what threads this depends on.  Based on the
> > context I can't verify that reg_shm_in will always be initialized
> > before you get to the free_shm_in label.
> >
> 
> You can find trusted_tee.c here [1].
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd.git/tree/security/keys/trusted-keys/trusted_tee.c

Thanks.  Looks good then :)

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2021-04-16 14:09 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-04-14  6:08 [PATCH] KEYS: trusted: fix a couple error pointer dereferences Dan Carpenter
2021-04-14 14:07 ` Serge E. Hallyn
2021-04-16 12:45   ` Sumit Garg
2021-04-16 14:08     ` Serge E. Hallyn
2021-04-16 12:42 ` Sumit Garg

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).