Re: [PATCH] KEYS: trusted: Fix memory leak on object td

Nick Desaulniers
2021-05-01T00:02:53Z

On Fri, Apr 30, 2021 at 4:37 AM Colin King <colin.king@canonical.com> wrote:
>
> From: Colin Ian King <colin.king@canonical.com>
>
> Two error return paths are neglecting to free allocated object td,
> causing a memory leak. Fix this by returning via the error return
> path that securely kfree's td.
>
> Fixes clang scan-build warning:
> security/keys/trusted-keys/trusted_tpm1.c:496:10: warning: Potential
> memory leak [unix.Malloc]
>
> Fixes: 5df16caada3f ("KEYS: trusted: Fix incorrect handling of tpm_get_random()")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

Thanks for the patch!
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

> ---
> security/keys/trusted-keys/trusted_tpm1.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c
> index 469394550801..aa108bea6739 100644
> --- a/security/keys/trusted-keys/trusted_tpm1.c
> +++ b/security/keys/trusted-keys/trusted_tpm1.c
> @@ -493,10 +493,12 @@ static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
>
> ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE);
> if (ret < 0)
> - return ret;
> + goto out;
>
> - if (ret != TPM_NONCE_SIZE)
> - return -EIO;
> + if (ret != TPM_NONCE_SIZE) {
> + ret = -EIO;
> + goto out;
> + }
>
> ordinal = htonl(TPM_ORD_SEAL);
> datsize = htonl(datalen);
> --
> 2.30.2
>

--
Thanks,
~Nick Desaulniers