lkml.org 
[lkml]   [2021]   [Jul]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH] security: keys: trusted: Fix memory leaks on allocated blob
Hi Colin,

On Fri, 23 Jul 2021 at 22:51, Colin King <colin.king@canonical.com> wrote:
>
> From: Colin Ian King <colin.king@canonical.com>
>
> There are several error return paths that don't kfree the allocated
> blob, leading to memory leaks. Ensure blob is initialized to null as
> some of the error return paths in function tpm2_key_decode do not
> change blob. Add an error return path to kfree blob and use this on
> the current leaky returns.
>

It looks like there are still leaky return paths left such as
tpm_buf_init() failure etc. which needs to be fixed as well.

With that addressed, feel free to add:

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

-Sumit

> Addresses-Coverity: ("Resource leak")
> Fixes: f2219745250f ("security: keys: trusted: use ASN.1 TPM2 key format for the blobs")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
> security/keys/trusted-keys/trusted_tpm2.c | 30 ++++++++++++++++-------
> 1 file changed, 21 insertions(+), 9 deletions(-)
>
> diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
> index 0165da386289..930c67f98611 100644
> --- a/security/keys/trusted-keys/trusted_tpm2.c
> +++ b/security/keys/trusted-keys/trusted_tpm2.c
> @@ -366,7 +366,7 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
> unsigned int private_len;
> unsigned int public_len;
> unsigned int blob_len;
> - u8 *blob, *pub;
> + u8 *blob = NULL, *pub;
> int rc;
> u32 attrs;
>
> @@ -378,22 +378,30 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
> }
>
> /* new format carries keyhandle but old format doesn't */
> - if (!options->keyhandle)
> - return -EINVAL;
> + if (!options->keyhandle) {
> + rc = -EINVAL;
> + goto err;
> + }
>
> /* must be big enough for at least the two be16 size counts */
> - if (payload->blob_len < 4)
> - return -EINVAL;
> + if (payload->blob_len < 4) {
> + rc = -EINVAL;
> + goto err;
> + }
>
> private_len = get_unaligned_be16(blob);
>
> /* must be big enough for following public_len */
> - if (private_len + 2 + 2 > (payload->blob_len))
> - return -E2BIG;
> + if (private_len + 2 + 2 > (payload->blob_len)) {
> + rc = -E2BIG;
> + goto err;
> + }
>
> public_len = get_unaligned_be16(blob + 2 + private_len);
> - if (private_len + 2 + public_len + 2 > payload->blob_len)
> - return -E2BIG;
> + if (private_len + 2 + public_len + 2 > payload->blob_len) {
> + rc = -E2BIG;
> + goto err;
> + }
>
> pub = blob + 2 + private_len + 2;
> /* key attributes are always at offset 4 */
> @@ -441,6 +449,10 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
> rc = -EPERM;
>
> return rc;
> +
> +err:
> + kfree(blob);
> + return rc;
> }
>
> /**
> --
> 2.31.1
>

\
 
 \ /
  Last update: 2021-07-26 07:35    [W:0.092 / U:1.428 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site