On Mon, 2021-04-12 at 17:01 +0100, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> 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 <colin.king@xxxxxxxxxxxxx>
> ---
> 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 <sumit.garg@xxxxxxxxxx>
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
