smack: Refactor to remove bprm_secureexec hook

The Smack bprm_secureexec hook can be merged with the bprm_set_creds
hook since it's dealing with the same information, and all of the details
are finalized during the first call to the bprm_set_creds hook via
prepare_binprm() (subsequent calls due to binfmt_script, etc, are ignored
via bprm->called_set_creds).

Here, the test can just happen at the end of the bprm_set_creds hook,
and the bprm_secureexec hook can be dropped.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
This commit is contained in:
Kees Cook 2017-07-18 15:25:26 -07:00
parent 62874c3adf
commit ccbb6e1065

View File

@ -950,6 +950,10 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm)
bsp->smk_task = isp->smk_task;
bprm->per_clear |= PER_CLEAR_ON_SETID;
/* Decide if this is a secure exec. */
if (bsp->smk_task != bsp->smk_forked)
bprm->secureexec = 1;
return 0;
}
@ -967,22 +971,6 @@ static void smack_bprm_committing_creds(struct linux_binprm *bprm)
current->pdeath_signal = 0;
}
/**
* smack_bprm_secureexec - Return the decision to use secureexec.
* @bprm: binprm for exec
*
* Returns 0 on success.
*/
static int smack_bprm_secureexec(struct linux_binprm *bprm)
{
struct task_smack *tsp = current_security();
if (tsp->smk_task != tsp->smk_forked)
return 1;
return 0;
}
/*
* Inode hooks
*/
@ -4646,7 +4634,6 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(bprm_set_creds, smack_bprm_set_creds),
LSM_HOOK_INIT(bprm_committing_creds, smack_bprm_committing_creds),
LSM_HOOK_INIT(bprm_secureexec, smack_bprm_secureexec),
LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security),
LSM_HOOK_INIT(inode_free_security, smack_inode_free_security),