apparmor: Refactor to remove bprm_secureexec hook

The AppArmor 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, all the comments describe how secureexec is actually calculated
during bprm_set_creds, so this actually does it, drops the bprm flag that
was being used internally by AppArmor, and drops the bprm_secureexec hook.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
This commit is contained in:
Kees Cook 2017-07-18 15:25:24 -07:00
parent c425e189ff
commit 993b3ab064
4 changed files with 1 additions and 23 deletions

View File

@ -807,7 +807,7 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
aa_label_printk(new, GFP_ATOMIC);
dbg_printk("\n");
}
bprm->unsafe |= AA_SECURE_X_NEEDED;
bprm->secureexec = 1;
}
if (label->proxy != new->proxy) {
@ -843,23 +843,6 @@ audit:
goto done;
}
/**
* apparmor_bprm_secureexec - determine if secureexec is needed
* @bprm: binprm for exec (NOT NULL)
*
* Returns: %1 if secureexec is needed else %0
*/
int apparmor_bprm_secureexec(struct linux_binprm *bprm)
{
/* the decision to use secure exec is computed in set_creds
* and stored in bprm->unsafe.
*/
if (bprm->unsafe & AA_SECURE_X_NEEDED)
return 1;
return 0;
}
/*
* Functions for self directed profile change
*/

View File

@ -30,7 +30,6 @@ struct aa_domain {
#define AA_CHANGE_STACK 8
int apparmor_bprm_set_creds(struct linux_binprm *bprm);
int apparmor_bprm_secureexec(struct linux_binprm *bprm);
void aa_free_domain_entries(struct aa_domain *domain);
int aa_change_hat(const char *hats[], int count, u64 token, int flags);

View File

@ -101,9 +101,6 @@ static inline struct aa_label *aa_get_file_label(struct aa_file_ctx *ctx)
#define AA_X_INHERIT 0x4000
#define AA_X_UNCONFINED 0x8000
/* AA_SECURE_X_NEEDED - is passed in the bprm->unsafe field */
#define AA_SECURE_X_NEEDED 0x8000
/* need to make conditional which ones are being set */
struct path_cond {
kuid_t uid;

View File

@ -694,7 +694,6 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(bprm_set_creds, apparmor_bprm_set_creds),
LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds),
LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds),
LSM_HOOK_INIT(bprm_secureexec, apparmor_bprm_secureexec),
LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit),
};