From: Colin Ian King <[email protected]>
The kzalloc call can return null with the GFP_KERNEL flag so
add a null check and exit via a new error exit label. Use the
same exit error label for another error path too.
Addresses-Coverity: ("Dereference null return value")
Fixes: 830027e2cb55 ("KEYS: trusted: Add generic trusted keys framework")
Signed-off-by: Colin Ian King <[email protected]>
---
security/keys/trusted-keys/trusted_core.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
index ec3a066a4b42..90774793f0b1 100644
--- a/security/keys/trusted-keys/trusted_core.c
+++ b/security/keys/trusted-keys/trusted_core.c
@@ -116,11 +116,13 @@ static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
ret = key_payload_reserve(key, sizeof(*p));
if (ret < 0)
- return p;
+ goto err;
p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (!p)
+ goto err;
p->migratable = migratable;
-
+err:
return p;
}
--
2.30.2
On Mon, 2021-04-12 at 17:01 +0100, Colin King wrote:
> From: Colin Ian King <[email protected]>
>
> The kzalloc call can return null with the GFP_KERNEL flag so
> add a null check and exit via a new error exit label. Use the
> same exit error label for another error path too.
>
> Addresses-Coverity: ("Dereference null return value")
> Fixes: 830027e2cb55 ("KEYS: trusted: Add generic trusted keys
> framework")
> Signed-off-by: Colin Ian King <[email protected]>
> ---
> security/keys/trusted-keys/trusted_core.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/security/keys/trusted-keys/trusted_core.c
> b/security/keys/trusted-keys/trusted_core.c
> index ec3a066a4b42..90774793f0b1 100644
> --- a/security/keys/trusted-keys/trusted_core.c
> +++ b/security/keys/trusted-keys/trusted_core.c
> @@ -116,11 +116,13 @@ static struct trusted_key_payload
> *trusted_payload_alloc(struct key *key)
>
> ret = key_payload_reserve(key, sizeof(*p));
> if (ret < 0)
> - return p;
> + goto err;
> p = kzalloc(sizeof(*p), GFP_KERNEL);
> + if (!p)
> + goto err;
>
> p->migratable = migratable;
> -
> +err:
> return p;
This is clearly a code migration bug in
commit 251c85bd106099e6f388a89e88e12d14de2c9cda
Author: Sumit Garg <[email protected]>
Date: Mon Mar 1 18:41:24 2021 +0530
KEYS: trusted: Add generic trusted keys framework
Which has for addition to trusted_core.c:
+static struct trusted_key_payload *trusted_payload_alloc(struct key
*key)
+{
+ struct trusted_key_payload *p = NULL;
+ int ret;
+
+ ret = key_payload_reserve(key, sizeof(*p));
+ if (ret < 0)
+ return p;
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+
+ p->migratable = migratable;
+
+ return p;
+}
And for trusted_tpm1.c:
-static struct trusted_key_payload *trusted_payload_alloc(struct key
*key)
-{
- struct trusted_key_payload *p = NULL;
- int ret;
-
- ret = key_payload_reserve(key, sizeof *p);
- if (ret < 0)
- return p;
- p = kzalloc(sizeof *p, GFP_KERNEL);
- if (p)
- p->migratable = 1; /* migratable by default */
- return p;
-}
The trusted_tpm1.c code was correct and we got this bug introduced by
what should have been a simple cut and paste ... how did that happen?
And therefore, how safe is the rest of the extraction into
trusted_core.c?
James
On 12/04/2021 17:48, James Bottomley wrote:
> On Mon, 2021-04-12 at 17:01 +0100, Colin King wrote:
>> From: Colin Ian King <[email protected]>
>>
>> The kzalloc call can return null with the GFP_KERNEL flag so
>> add a null check and exit via a new error exit label. Use the
>> same exit error label for another error path too.
>>
>> Addresses-Coverity: ("Dereference null return value")
>> Fixes: 830027e2cb55 ("KEYS: trusted: Add generic trusted keys
>> framework")
>> Signed-off-by: Colin Ian King <[email protected]>
>> ---
>> security/keys/trusted-keys/trusted_core.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/security/keys/trusted-keys/trusted_core.c
>> b/security/keys/trusted-keys/trusted_core.c
>> index ec3a066a4b42..90774793f0b1 100644
>> --- a/security/keys/trusted-keys/trusted_core.c
>> +++ b/security/keys/trusted-keys/trusted_core.c
>> @@ -116,11 +116,13 @@ static struct trusted_key_payload
>> *trusted_payload_alloc(struct key *key)
>>
>> ret = key_payload_reserve(key, sizeof(*p));
>> if (ret < 0)
>> - return p;
>> + goto err;
>> p = kzalloc(sizeof(*p), GFP_KERNEL);
>> + if (!p)
>> + goto err;
>>
>> p->migratable = migratable;
>> -
>> +err:
>> return p;
>
> This is clearly a code migration bug in
>
> commit 251c85bd106099e6f388a89e88e12d14de2c9cda
> Author: Sumit Garg <[email protected]>
> Date: Mon Mar 1 18:41:24 2021 +0530
>
> KEYS: trusted: Add generic trusted keys framework
>
> Which has for addition to trusted_core.c:
>
> +static struct trusted_key_payload *trusted_payload_alloc(struct key
> *key)
> +{
> + struct trusted_key_payload *p = NULL;
> + int ret;
> +
> + ret = key_payload_reserve(key, sizeof(*p));
> + if (ret < 0)
> + return p;
> + p = kzalloc(sizeof(*p), GFP_KERNEL);
> +
> + p->migratable = migratable;
> +
> + return p;
> +}
>
> And for trusted_tpm1.c:
>
> -static struct trusted_key_payload *trusted_payload_alloc(struct key
> *key)
> -{
> - struct trusted_key_payload *p = NULL;
> - int ret;
> -
> - ret = key_payload_reserve(key, sizeof *p);
> - if (ret < 0)
> - return p;
> - p = kzalloc(sizeof *p, GFP_KERNEL);
> - if (p)
> - p->migratable = 1; /* migratable by default */
> - return p;
> -}
>
> The trusted_tpm1.c code was correct and we got this bug introduced by
> what should have been a simple cut and paste ... how did that happen?
> And therefore, how safe is the rest of the extraction into
> trusted_core.c?
>
fortunately it gets caught by static analysis, but it does make me also
concerned about what else has changed and how this gets through review.
> James
>
>
On Mon, 12 Apr 2021 at 22:34, Colin Ian King <[email protected]> wrote:
>
> On 12/04/2021 17:48, James Bottomley wrote:
> > On Mon, 2021-04-12 at 17:01 +0100, Colin King wrote:
> >> From: Colin Ian King <[email protected]>
> >>
> >> The kzalloc call can return null with the GFP_KERNEL flag so
> >> add a null check and exit via a new error exit label. Use the
> >> same exit error label for another error path too.
> >>
> >> Addresses-Coverity: ("Dereference null return value")
> >> Fixes: 830027e2cb55 ("KEYS: trusted: Add generic trusted keys
> >> framework")
> >> Signed-off-by: Colin Ian King <[email protected]>
> >> ---
> >> security/keys/trusted-keys/trusted_core.c | 6 ++++--
> >> 1 file changed, 4 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/security/keys/trusted-keys/trusted_core.c
> >> b/security/keys/trusted-keys/trusted_core.c
> >> index ec3a066a4b42..90774793f0b1 100644
> >> --- a/security/keys/trusted-keys/trusted_core.c
> >> +++ b/security/keys/trusted-keys/trusted_core.c
> >> @@ -116,11 +116,13 @@ static struct trusted_key_payload
> >> *trusted_payload_alloc(struct key *key)
> >>
> >> ret = key_payload_reserve(key, sizeof(*p));
> >> if (ret < 0)
> >> - return p;
> >> + goto err;
> >> p = kzalloc(sizeof(*p), GFP_KERNEL);
> >> + if (!p)
> >> + goto err;
> >>
> >> p->migratable = migratable;
> >> -
> >> +err:
> >> return p;
> >
> > This is clearly a code migration bug in
> >
> > commit 251c85bd106099e6f388a89e88e12d14de2c9cda
> > Author: Sumit Garg <[email protected]>
> > Date: Mon Mar 1 18:41:24 2021 +0530
> >
> > KEYS: trusted: Add generic trusted keys framework
> >
> > Which has for addition to trusted_core.c:
> >
> > +static struct trusted_key_payload *trusted_payload_alloc(struct key
> > *key)
> > +{
> > + struct trusted_key_payload *p = NULL;
> > + int ret;
> > +
> > + ret = key_payload_reserve(key, sizeof(*p));
> > + if (ret < 0)
> > + return p;
> > + p = kzalloc(sizeof(*p), GFP_KERNEL);
> > +
> > + p->migratable = migratable;
> > +
> > + return p;
> > +}
> >
> > And for trusted_tpm1.c:
> >
> > -static struct trusted_key_payload *trusted_payload_alloc(struct key
> > *key)
> > -{
> > - struct trusted_key_payload *p = NULL;
> > - int ret;
> > -
> > - ret = key_payload_reserve(key, sizeof *p);
> > - if (ret < 0)
> > - return p;
> > - p = kzalloc(sizeof *p, GFP_KERNEL);
> > - if (p)
> > - p->migratable = 1; /* migratable by default */
> > - return p;
> > -}
> >
> > The trusted_tpm1.c code was correct and we got this bug introduced by
> > what should have been a simple cut and paste ... how did that happen?
It was a little more than just cut and paste where I did generalized
"migratable" flag to be provided by the corresponding trust source's
ops struct.
> > And therefore, how safe is the rest of the extraction into
> > trusted_core.c?
> >
>
> fortunately it gets caught by static analysis, but it does make me also
> concerned about what else has changed and how this gets through review.
>
I agree that extraction into trusted_core.c was a complex change but
this patch has been up for review for almost 2 years [1]. And
extensive testing can't catch this sort of bug as allocation wouldn't
normally fail.
[1] https://lwn.net/Articles/795416/
-Sumit
> > James
> >
> >
>
On Mon, 12 Apr 2021 at 21:31, Colin King <[email protected]> wrote:
>
> From: Colin Ian King <[email protected]>
>
> The kzalloc call can return null with the GFP_KERNEL flag so
> add a null check and exit via a new error exit label. Use the
> same exit error label for another error path too.
>
> Addresses-Coverity: ("Dereference null return value")
> Fixes: 830027e2cb55 ("KEYS: trusted: Add generic trusted keys framework")
> Signed-off-by: Colin Ian King <[email protected]>
> ---
> security/keys/trusted-keys/trusted_core.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
Ah, it's my bad. Thanks for fixing this issue.
Reviewed-by: Sumit Garg <[email protected]>
-Sumit
> diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
> index ec3a066a4b42..90774793f0b1 100644
> --- a/security/keys/trusted-keys/trusted_core.c
> +++ b/security/keys/trusted-keys/trusted_core.c
> @@ -116,11 +116,13 @@ static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
>
> ret = key_payload_reserve(key, sizeof(*p));
> if (ret < 0)
> - return p;
> + goto err;
> p = kzalloc(sizeof(*p), GFP_KERNEL);
> + if (!p)
> + goto err;
>
> p->migratable = migratable;
> -
> +err:
> return p;
> }
>
> --
> 2.30.2
>
On Mon, Apr 12, 2021 at 05:01:01PM +0100, Colin King wrote:
> From: Colin Ian King <[email protected]>
>
> The kzalloc call can return null with the GFP_KERNEL flag so
> add a null check and exit via a new error exit label. Use the
> same exit error label for another error path too.
>
> Addresses-Coverity: ("Dereference null return value")
> Fixes: 830027e2cb55 ("KEYS: trusted: Add generic trusted keys framework")
> Signed-off-by: Colin Ian King <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
/Jarkko