[PATCH v4 04/19] SELinux: Remove cred security blob poisoning
flat view
From: Kees Cook <hidden>
Date: 2018-09-22 08:35:11
Also in:
linux-fsdevel, lkml, selinux
On Fri, Sep 21, 2018 at 5:17 PM, Casey Schaufler [off-list ref] wrote:
The SELinux specific credential poisioning only makes sense if SELinux is managing the credentials. As the intent of this patch set is to move the blob management out of the modules and into the infrastructure, the SELinux specific code has to go. The poisioning could be introduced into the infrastructure at some later date. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <redacted> -Kees
quoted hunk ↗ jump to hunk
--- kernel/cred.c | 13 ------------- security/selinux/hooks.c | 6 ------ 2 files changed, 19 deletions(-)diff --git a/kernel/cred.c b/kernel/cred.c index ecf03657e71c..fa2061ee4955 100644 --- a/kernel/cred.c +++ b/kernel/cred.c@@ -704,19 +704,6 @@ bool creds_are_invalid(const struct cred *cred) { if (cred->magic != CRED_MAGIC) return true; -#ifdef CONFIG_SECURITY_SELINUX - /* - * cred->security == NULL if security_cred_alloc_blank() or - * security_prepare_creds() returned an error. - */ - if (selinux_is_enabled() && cred->security) { - if ((unsigned long) cred->security < PAGE_SIZE) - return true; - if ((*(u32 *)cred->security & 0xffffff00) == - (POISON_FREE << 24 | POISON_FREE << 16 | POISON_FREE << 8)) - return true; - } -#endif return false; } EXPORT_SYMBOL(creds_are_invalid);diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 9d6cdd21acb6..80614ca25a2b 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c@@ -3920,12 +3920,6 @@ static void selinux_cred_free(struct cred *cred) { struct task_security_struct *tsec = selinux_cred(cred); - /* - * cred->security == NULL if security_cred_alloc_blank() or - * security_prepare_creds() returned an error. - */ - BUG_ON(cred->security && (unsigned long) cred->security < PAGE_SIZE); - cred->security = (void *) 0x7UL; kfree(tsec); } --2.17.1
-- Kees Cook Pixel Security