On Fri, 11 Jan 2019, Casey Schaufler wrote:
> >From 47134986133c822e1d88860fa2b108f92c97a7ff Mon Sep 17 00:00:00 2001
> From: Casey Schaufler <[email protected]>
> Date: Fri, 11 Jan 2019 17:31:50 -0800
> Subject: [PATCH 1/2] LSM: Check for NULL cred-security on free
>
> Check that the cred security blob has been set before trying
> to clean it up. There is a case during credential initialization
> that could result in this.
>
> Signed-off-by: Casey Schaufler <[email protected]>
JJ: does this fix the problem?
> ---
> security/security.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/security/security.c b/security/security.c
> index a618e22df5c6..7bffc86d4e87 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1477,6 +1477,13 @@ int security_cred_alloc_blank(struct cred *cred, gfp_t
> gfp)
>
> void security_cred_free(struct cred *cred)
> {
> + /*
> + * There is a failure case in prepare_creds() that
> + * may result in a call here with ->security being NULL.
> + */
> + if (unlikely(cred->security == NULL))
> + return;
> +
> call_void_hook(cred_free, cred);
>
> kfree(cred->security);
>
--
James Morris
<[email protected]>
