diff mbox

[V3,04/10] capabilities: use root_priveleged inline to clarify logic

Message ID cf456cee4480719b861c5f62f0d96f9083f9f3c4.1503459890.git.rgb@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Richard Guy Briggs Aug. 23, 2017, 10:12 a.m. UTC
Introduce inline root_privileged() to make use of SECURE_NONROOT
easier to read.

Suggested-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
---
 security/commoncap.c |    9 +++++----
 1 files changed, 5 insertions(+), 4 deletions(-)

Comments

Serge E. Hallyn Aug. 24, 2017, 4:14 p.m. UTC | #1
Quoting Richard Guy Briggs (rgb@redhat.com):
> Introduce inline root_privileged() to make use of SECURE_NONROOT
> easier to read.
> 
> Suggested-by: Serge Hallyn <serge@hallyn.com>

Reviewed-by: Serge Hallyn <serge@hallyn.com>

> Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> ---
>  security/commoncap.c |    9 +++++----
>  1 files changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/security/commoncap.c b/security/commoncap.c
> index 028d4e4..36c38a1 100644
> --- a/security/commoncap.c
> +++ b/security/commoncap.c
> @@ -481,13 +481,13 @@ static int get_file_caps(struct linux_binprm *bprm, bool *effective, bool *has_f
>  	return rc;
>  }
>  
> +static inline bool root_privileged(void) { return !issecure(SECURE_NOROOT); }
> +
>  void handle_privileged_root(struct linux_binprm *bprm, bool has_fcap, bool *effective, kuid_t root_uid)
>  {
>  	const struct cred *old = current_cred();
>  	struct cred *new = bprm->cred;
>  
> -	if (issecure(SECURE_NOROOT))
> -		return;
>  	/*
>  	 * If the legacy file capability is set, then don't set privs
>  	 * for a setuid root binary run by a non-root user.  Do set it
> @@ -544,7 +544,8 @@ int cap_bprm_set_creds(struct linux_binprm *bprm)
>  
>  	root_uid = make_kuid(new->user_ns, 0);
>  
> -	handle_privileged_root(bprm, has_fcap, &effective, root_uid);
> +	if (root_privileged())
> +		handle_privileged_root(bprm, has_fcap, &effective, root_uid);
>  
>  	/* if we have fs caps, clear dangerous personality flags */
>  	if (cap_gained(permitted, new, old))
> @@ -612,7 +613,7 @@ int cap_bprm_set_creds(struct linux_binprm *bprm)
>  	if (cap_grew(effective, ambient, new)) {
>  		if (!cap_full(effective, new) ||
>  		    !uid_eq(new->euid, root_uid) || !uid_eq(new->uid, root_uid) ||
> -		    issecure(SECURE_NOROOT)) {
> +		    !root_privileged()) {
>  			ret = audit_log_bprm_fcaps(bprm, new, old);
>  			if (ret < 0)
>  				return ret;
> -- 
> 1.7.1
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James Morris Aug. 25, 2017, 5:58 a.m. UTC | #2
On Wed, 23 Aug 2017, Richard Guy Briggs wrote:

> Introduce inline root_privileged() to make use of SECURE_NONROOT
> easier to read.
> 
> Suggested-by: Serge Hallyn <serge@hallyn.com>
> Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> ---
>  security/commoncap.c |    9 +++++----
>  1 files changed, 5 insertions(+), 4 deletions(-)


Acked-by: James Morris <james.l.morris@oracle.com>
Richard Guy Briggs Aug. 28, 2017, 12:03 p.m. UTC | #3
On 2017-08-25 15:58, James Morris wrote:
> On Wed, 23 Aug 2017, Richard Guy Briggs wrote:
> 
> > Introduce inline root_privileged() to make use of SECURE_NONROOT
> > easier to read.
> > 
> > Suggested-by: Serge Hallyn <serge@hallyn.com>
> > Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> > ---
> >  security/commoncap.c |    9 +++++----
> >  1 files changed, 5 insertions(+), 4 deletions(-)
> 
> Acked-by: James Morris <james.l.morris@oracle.com>

Does anyone have the appetite to move this helper function to
include/linux/securebits.h along with issecure() to make it more widely
available?

> James Morris

- RGB

--
Richard Guy Briggs <rgb@redhat.com>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635
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Serge E. Hallyn Aug. 31, 2017, 2:49 p.m. UTC | #4
Quoting Richard Guy Briggs (rgb@redhat.com):
> On 2017-08-25 15:58, James Morris wrote:
> > On Wed, 23 Aug 2017, Richard Guy Briggs wrote:
> > 
> > > Introduce inline root_privileged() to make use of SECURE_NONROOT
> > > easier to read.
> > > 
> > > Suggested-by: Serge Hallyn <serge@hallyn.com>
> > > Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> > > ---
> > >  security/commoncap.c |    9 +++++----
> > >  1 files changed, 5 insertions(+), 4 deletions(-)
> > 
> > Acked-by: James Morris <james.l.morris@oracle.com>
> 
> Does anyone have the appetite to move this helper function to
> include/linux/securebits.h along with issecure() to make it more widely
> available?

If it's going to have wider scope, then it probably needs to be
renamed to be unambiguous in any context.  root_implies_privilege
or uid0_is_privileged maybe?   Maybe root_privileged() is ok...
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diff mbox

Patch

diff --git a/security/commoncap.c b/security/commoncap.c
index 028d4e4..36c38a1 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -481,13 +481,13 @@  static int get_file_caps(struct linux_binprm *bprm, bool *effective, bool *has_f
 	return rc;
 }
 
+static inline bool root_privileged(void) { return !issecure(SECURE_NOROOT); }
+
 void handle_privileged_root(struct linux_binprm *bprm, bool has_fcap, bool *effective, kuid_t root_uid)
 {
 	const struct cred *old = current_cred();
 	struct cred *new = bprm->cred;
 
-	if (issecure(SECURE_NOROOT))
-		return;
 	/*
 	 * If the legacy file capability is set, then don't set privs
 	 * for a setuid root binary run by a non-root user.  Do set it
@@ -544,7 +544,8 @@  int cap_bprm_set_creds(struct linux_binprm *bprm)
 
 	root_uid = make_kuid(new->user_ns, 0);
 
-	handle_privileged_root(bprm, has_fcap, &effective, root_uid);
+	if (root_privileged())
+		handle_privileged_root(bprm, has_fcap, &effective, root_uid);
 
 	/* if we have fs caps, clear dangerous personality flags */
 	if (cap_gained(permitted, new, old))
@@ -612,7 +613,7 @@  int cap_bprm_set_creds(struct linux_binprm *bprm)
 	if (cap_grew(effective, ambient, new)) {
 		if (!cap_full(effective, new) ||
 		    !uid_eq(new->euid, root_uid) || !uid_eq(new->uid, root_uid) ||
-		    issecure(SECURE_NOROOT)) {
+		    !root_privileged()) {
 			ret = audit_log_bprm_fcaps(bprm, new, old);
 			if (ret < 0)
 				return ret;