[PATCH] SELinux: Create a common helper to determine an inode label [ver #3]

[PATCH] SELinux: Create a common helper to determine an inode label [ver #3]

[David Howells]

    
Create a common helper function to determine the label for a new inode.
This is then used by:

	- may_create()
	- selinux_dentry_init_security()
	- selinux_inode_init_security()

This will change the behaviour of the functions slightly, bringing them all
into line.

Suggested-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: David Howells <dhowells@redhat.com>
---
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index ffa5a642629a..ec30e599fb46 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1684,6 +1684,32 @@ out:
 	return rc;
 }
 
+/*
+ * Determine the label for an inode that might be unioned.
+ */
+static int selinux_determine_inode_label(const struct inode *dir,
+					 const struct qstr *name,
+					 u16 tclass,
+					 u32 *_new_isid)
+{
+	const struct superblock_security_struct *sbsec = dir->i_sb->s_security;
+	const struct inode_security_struct *dsec = dir->i_security;
+	const struct task_security_struct *tsec = current_security();
+
+	if ((sbsec->flags & SE_SBINITIALIZED) &&
+	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
+		*_new_isid = sbsec->mntpoint_sid;
+	} else if ((sbsec->flags & SBLABEL_MNT) &&
+		   tsec->create_sid) {
+		*_new_isid = tsec->create_sid;
+	} else {
+		return security_transition_sid(tsec->sid, dsec->sid, tclass,
+					       name, _new_isid);
+	}
+
+	return 0;
+}
+
 /* Check whether a task can create a file. */
 static int may_create(struct inode *dir,
 		      struct dentry *dentry,
@@ -1700,7 +1726,6 @@ static int may_create(struct inode *dir,
 	sbsec = dir->i_sb->s_security;
 
 	sid = tsec->sid;
-	newsid = tsec->create_sid;
 
 	ad.type = LSM_AUDIT_DATA_DENTRY;
 	ad.u.dentry = dentry;
@@ -1711,12 +1736,10 @@ static int may_create(struct inode *dir,
 	if (rc)
 		return rc;
 
-	if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
-		rc = security_transition_sid(sid, dsec->sid, tclass,
-					     &dentry->d_name, &newsid);
-		if (rc)
-			return rc;
-	}
+	rc = selinux_determine_inode_label(dir, &dentry->d_name, tclass,
+					   &newsid);
+	if (rc)
+		return rc;
 
 	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
 	if (rc)
@@ -2723,32 +2746,14 @@ static int selinux_dentry_init_security(struct dentry *dentry, int mode,
 					struct qstr *name, void **ctx,
 					u32 *ctxlen)
 {
-	const struct cred *cred = current_cred();
-	struct task_security_struct *tsec;
-	struct inode_security_struct *dsec;
-	struct superblock_security_struct *sbsec;
-	struct inode *dir = d_backing_inode(dentry->d_parent);
 	u32 newsid;
 	int rc;
 
-	tsec = cred->security;
-	dsec = dir->i_security;
-	sbsec = dir->i_sb->s_security;
-
-	if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
-		newsid = tsec->create_sid;
-	} else {
-		rc = security_transition_sid(tsec->sid, dsec->sid,
-					     inode_mode_to_security_class(mode),
-					     name,
-					     &newsid);
-		if (rc) {
-			printk(KERN_WARNING
-				"%s: security_transition_sid failed, rc=%d\n",
-			       __func__, -rc);
-			return rc;
-		}
-	}
+	rc = selinux_determine_inode_label(d_inode(dentry->d_parent), name,
+					   inode_mode_to_security_class(mode),
+					   &newsid);
+	if (rc)
+		return rc;
 
 	return security_sid_to_context(newsid, (char **)ctx, ctxlen);
 }
@@ -2771,22 +2776,12 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
 	sid = tsec->sid;
 	newsid = tsec->create_sid;
 
-	if ((sbsec->flags & SE_SBINITIALIZED) &&
-	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
-		newsid = sbsec->mntpoint_sid;
-	else if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
-		rc = security_transition_sid(sid, dsec->sid,
-					     inode_mode_to_security_class(inode->i_mode),
-					     qstr, &newsid);
-		if (rc) {
-			printk(KERN_WARNING "%s:  "
-			       "security_transition_sid failed, rc=%d (dev=%s "
-			       "ino=%ld)\n",
-			       __func__,
-			       -rc, inode->i_sb->s_id, inode->i_ino);
-			return rc;
-		}
-	}
+	rc = selinux_determine_inode_label(
+		dir, qstr,
+		inode_mode_to_security_class(inode->i_mode),
+		&newsid);
+	if (rc)
+		return rc;
 
 	/* Possibly defer initialization to selinux_complete_init. */
 	if (sbsec->flags & SE_SBINITIALIZED) {

[PATCH] SELinux: Create a common helper to determine an inode label [ver #3]

[David Howells]

    
Create a common helper function to determine the label for a new inode.
This is then used by:

	- may_create()
	- selinux_dentry_init_security()
	- selinux_inode_init_security()

This will change the behaviour of the functions slightly, bringing them all
into line.

Suggested-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: David Howells <dhowells@redhat.com>
---
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index ffa5a642629a..ec30e599fb46 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1684,6 +1684,32 @@ out:
 	return rc;
 }
 
+/*
+ * Determine the label for an inode that might be unioned.
+ */
+static int selinux_determine_inode_label(const struct inode *dir,
+					 const struct qstr *name,
+					 u16 tclass,
+					 u32 *_new_isid)
+{
+	const struct superblock_security_struct *sbsec = dir->i_sb->s_security;
+	const struct inode_security_struct *dsec = dir->i_security;
+	const struct task_security_struct *tsec = current_security();
+
+	if ((sbsec->flags & SE_SBINITIALIZED) &&
+	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
+		*_new_isid = sbsec->mntpoint_sid;
+	} else if ((sbsec->flags & SBLABEL_MNT) &&
+		   tsec->create_sid) {
+		*_new_isid = tsec->create_sid;
+	} else {
+		return security_transition_sid(tsec->sid, dsec->sid, tclass,
+					       name, _new_isid);
+	}
+
+	return 0;
+}
+
 /* Check whether a task can create a file. */
 static int may_create(struct inode *dir,
 		      struct dentry *dentry,
@@ -1700,7 +1726,6 @@ static int may_create(struct inode *dir,
 	sbsec = dir->i_sb->s_security;
 
 	sid = tsec->sid;
-	newsid = tsec->create_sid;
 
 	ad.type = LSM_AUDIT_DATA_DENTRY;
 	ad.u.dentry = dentry;
@@ -1711,12 +1736,10 @@ static int may_create(struct inode *dir,
 	if (rc)
 		return rc;
 
-	if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
-		rc = security_transition_sid(sid, dsec->sid, tclass,
-					     &dentry->d_name, &newsid);
-		if (rc)
-			return rc;
-	}
+	rc = selinux_determine_inode_label(dir, &dentry->d_name, tclass,
+					   &newsid);
+	if (rc)
+		return rc;
 
 	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
 	if (rc)
@@ -2723,32 +2746,14 @@ static int selinux_dentry_init_security(struct dentry *dentry, int mode,
 					struct qstr *name, void **ctx,
 					u32 *ctxlen)
 {
-	const struct cred *cred = current_cred();
-	struct task_security_struct *tsec;
-	struct inode_security_struct *dsec;
-	struct superblock_security_struct *sbsec;
-	struct inode *dir = d_backing_inode(dentry->d_parent);
 	u32 newsid;
 	int rc;
 
-	tsec = cred->security;
-	dsec = dir->i_security;
-	sbsec = dir->i_sb->s_security;
-
-	if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
-		newsid = tsec->create_sid;
-	} else {
-		rc = security_transition_sid(tsec->sid, dsec->sid,
-					     inode_mode_to_security_class(mode),
-					     name,
-					     &newsid);
-		if (rc) {
-			printk(KERN_WARNING
-				"%s: security_transition_sid failed, rc=%d\n",
-			       __func__, -rc);
-			return rc;
-		}
-	}
+	rc = selinux_determine_inode_label(d_inode(dentry->d_parent), name,
+					   inode_mode_to_security_class(mode),
+					   &newsid);
+	if (rc)
+		return rc;
 
 	return security_sid_to_context(newsid, (char **)ctx, ctxlen);
 }
@@ -2771,22 +2776,12 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
 	sid = tsec->sid;
 	newsid = tsec->create_sid;
 
-	if ((sbsec->flags & SE_SBINITIALIZED) &&
-	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
-		newsid = sbsec->mntpoint_sid;
-	else if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
-		rc = security_transition_sid(sid, dsec->sid,
-					     inode_mode_to_security_class(inode->i_mode),
-					     qstr, &newsid);
-		if (rc) {
-			printk(KERN_WARNING "%s:  "
-			       "security_transition_sid failed, rc=%d (dev=%s "
-			       "ino=%ld)\n",
-			       __func__,
-			       -rc, inode->i_sb->s_id, inode->i_ino);
-			return rc;
-		}
-	}
+	rc = selinux_determine_inode_label(
+		dir, qstr,
+		inode_mode_to_security_class(inode->i_mode),
+		&newsid);
+	if (rc)
+		return rc;
 
 	/* Possibly defer initialization to selinux_complete_init. */
 	if (sbsec->flags & SE_SBINITIALIZED) {

Re: [PATCH] SELinux: Create a common helper to determine an inode label [ver #3]

[Stephen Smalley]

On 06/18/2015 02:25 PM, David Howells wrote:
>     
> Create a common helper function to determine the label for a new inode.
> This is then used by:
> 
> 	- may_create()
> 	- selinux_dentry_init_security()
> 	- selinux_inode_init_security()
> 
> This will change the behaviour of the functions slightly, bringing them all
> into line.
> 
> Suggested-by: Stephen Smalley <sds@tycho.nsa.gov>
> Signed-off-by: David Howells <dhowells@redhat.com>

Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>

> ---
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index ffa5a642629a..ec30e599fb46 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -1684,6 +1684,32 @@ out:
>  	return rc;
>  }
>  
> +/*
> + * Determine the label for an inode that might be unioned.
> + */
> +static int selinux_determine_inode_label(const struct inode *dir,
> +					 const struct qstr *name,
> +					 u16 tclass,
> +					 u32 *_new_isid)
> +{
> +	const struct superblock_security_struct *sbsec = dir->i_sb->s_security;
> +	const struct inode_security_struct *dsec = dir->i_security;
> +	const struct task_security_struct *tsec = current_security();
> +
> +	if ((sbsec->flags & SE_SBINITIALIZED) &&
> +	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
> +		*_new_isid = sbsec->mntpoint_sid;
> +	} else if ((sbsec->flags & SBLABEL_MNT) &&
> +		   tsec->create_sid) {
> +		*_new_isid = tsec->create_sid;
> +	} else {
> +		return security_transition_sid(tsec->sid, dsec->sid, tclass,
> +					       name, _new_isid);
> +	}
> +
> +	return 0;
> +}
> +
>  /* Check whether a task can create a file. */
>  static int may_create(struct inode *dir,
>  		      struct dentry *dentry,
> @@ -1700,7 +1726,6 @@ static int may_create(struct inode *dir,
>  	sbsec = dir->i_sb->s_security;
>  
>  	sid = tsec->sid;
> -	newsid = tsec->create_sid;
>  
>  	ad.type = LSM_AUDIT_DATA_DENTRY;
>  	ad.u.dentry = dentry;
> @@ -1711,12 +1736,10 @@ static int may_create(struct inode *dir,
>  	if (rc)
>  		return rc;
>  
> -	if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
> -		rc = security_transition_sid(sid, dsec->sid, tclass,
> -					     &dentry->d_name, &newsid);
> -		if (rc)
> -			return rc;
> -	}
> +	rc = selinux_determine_inode_label(dir, &dentry->d_name, tclass,
> +					   &newsid);
> +	if (rc)
> +		return rc;
>  
>  	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
>  	if (rc)
> @@ -2723,32 +2746,14 @@ static int selinux_dentry_init_security(struct dentry *dentry, int mode,
>  					struct qstr *name, void **ctx,
>  					u32 *ctxlen)
>  {
> -	const struct cred *cred = current_cred();
> -	struct task_security_struct *tsec;
> -	struct inode_security_struct *dsec;
> -	struct superblock_security_struct *sbsec;
> -	struct inode *dir = d_backing_inode(dentry->d_parent);
>  	u32 newsid;
>  	int rc;
>  
> -	tsec = cred->security;
> -	dsec = dir->i_security;
> -	sbsec = dir->i_sb->s_security;
> -
> -	if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
> -		newsid = tsec->create_sid;
> -	} else {
> -		rc = security_transition_sid(tsec->sid, dsec->sid,
> -					     inode_mode_to_security_class(mode),
> -					     name,
> -					     &newsid);
> -		if (rc) {
> -			printk(KERN_WARNING
> -				"%s: security_transition_sid failed, rc=%d\n",
> -			       __func__, -rc);
> -			return rc;
> -		}
> -	}
> +	rc = selinux_determine_inode_label(d_inode(dentry->d_parent), name,
> +					   inode_mode_to_security_class(mode),
> +					   &newsid);
> +	if (rc)
> +		return rc;
>  
>  	return security_sid_to_context(newsid, (char **)ctx, ctxlen);
>  }
> @@ -2771,22 +2776,12 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
>  	sid = tsec->sid;
>  	newsid = tsec->create_sid;
>  
> -	if ((sbsec->flags & SE_SBINITIALIZED) &&
> -	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
> -		newsid = sbsec->mntpoint_sid;
> -	else if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
> -		rc = security_transition_sid(sid, dsec->sid,
> -					     inode_mode_to_security_class(inode->i_mode),
> -					     qstr, &newsid);
> -		if (rc) {
> -			printk(KERN_WARNING "%s:  "
> -			       "security_transition_sid failed, rc=%d (dev=%s "
> -			       "ino=%ld)\n",
> -			       __func__,
> -			       -rc, inode->i_sb->s_id, inode->i_ino);
> -			return rc;
> -		}
> -	}
> +	rc = selinux_determine_inode_label(
> +		dir, qstr,
> +		inode_mode_to_security_class(inode->i_mode),
> +		&newsid);
> +	if (rc)
> +		return rc;
>  
>  	/* Possibly defer initialization to selinux_complete_init. */
>  	if (sbsec->flags & SE_SBINITIALIZED) {
> 
> 

Re: [PATCH] SELinux: Create a common helper to determine an inode label [ver #3]

[Stephen Smalley]

On 06/18/2015 02:25 PM, David Howells wrote:
>     
> Create a common helper function to determine the label for a new inode.
> This is then used by:
> 
> 	- may_create()
> 	- selinux_dentry_init_security()
> 	- selinux_inode_init_security()
> 
> This will change the behaviour of the functions slightly, bringing them all
> into line.
> 
> Suggested-by: Stephen Smalley <sds@tycho.nsa.gov>
> Signed-off-by: David Howells <dhowells@redhat.com>

Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>

> ---
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index ffa5a642629a..ec30e599fb46 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -1684,6 +1684,32 @@ out:
>  	return rc;
>  }
>  
> +/*
> + * Determine the label for an inode that might be unioned.
> + */
> +static int selinux_determine_inode_label(const struct inode *dir,
> +					 const struct qstr *name,
> +					 u16 tclass,
> +					 u32 *_new_isid)
> +{
> +	const struct superblock_security_struct *sbsec = dir->i_sb->s_security;
> +	const struct inode_security_struct *dsec = dir->i_security;
> +	const struct task_security_struct *tsec = current_security();
> +
> +	if ((sbsec->flags & SE_SBINITIALIZED) &&
> +	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
> +		*_new_isid = sbsec->mntpoint_sid;
> +	} else if ((sbsec->flags & SBLABEL_MNT) &&
> +		   tsec->create_sid) {
> +		*_new_isid = tsec->create_sid;
> +	} else {
> +		return security_transition_sid(tsec->sid, dsec->sid, tclass,
> +					       name, _new_isid);
> +	}
> +
> +	return 0;
> +}
> +
>  /* Check whether a task can create a file. */
>  static int may_create(struct inode *dir,
>  		      struct dentry *dentry,
> @@ -1700,7 +1726,6 @@ static int may_create(struct inode *dir,
>  	sbsec = dir->i_sb->s_security;
>  
>  	sid = tsec->sid;
> -	newsid = tsec->create_sid;
>  
>  	ad.type = LSM_AUDIT_DATA_DENTRY;
>  	ad.u.dentry = dentry;
> @@ -1711,12 +1736,10 @@ static int may_create(struct inode *dir,
>  	if (rc)
>  		return rc;
>  
> -	if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
> -		rc = security_transition_sid(sid, dsec->sid, tclass,
> -					     &dentry->d_name, &newsid);
> -		if (rc)
> -			return rc;
> -	}
> +	rc = selinux_determine_inode_label(dir, &dentry->d_name, tclass,
> +					   &newsid);
> +	if (rc)
> +		return rc;
>  
>  	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
>  	if (rc)
> @@ -2723,32 +2746,14 @@ static int selinux_dentry_init_security(struct dentry *dentry, int mode,
>  					struct qstr *name, void **ctx,
>  					u32 *ctxlen)
>  {
> -	const struct cred *cred = current_cred();
> -	struct task_security_struct *tsec;
> -	struct inode_security_struct *dsec;
> -	struct superblock_security_struct *sbsec;
> -	struct inode *dir = d_backing_inode(dentry->d_parent);
>  	u32 newsid;
>  	int rc;
>  
> -	tsec = cred->security;
> -	dsec = dir->i_security;
> -	sbsec = dir->i_sb->s_security;
> -
> -	if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
> -		newsid = tsec->create_sid;
> -	} else {
> -		rc = security_transition_sid(tsec->sid, dsec->sid,
> -					     inode_mode_to_security_class(mode),
> -					     name,
> -					     &newsid);
> -		if (rc) {
> -			printk(KERN_WARNING
> -				"%s: security_transition_sid failed, rc=%d\n",
> -			       __func__, -rc);
> -			return rc;
> -		}
> -	}
> +	rc = selinux_determine_inode_label(d_inode(dentry->d_parent), name,
> +					   inode_mode_to_security_class(mode),
> +					   &newsid);
> +	if (rc)
> +		return rc;
>  
>  	return security_sid_to_context(newsid, (char **)ctx, ctxlen);
>  }
> @@ -2771,22 +2776,12 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
>  	sid = tsec->sid;
>  	newsid = tsec->create_sid;
>  
> -	if ((sbsec->flags & SE_SBINITIALIZED) &&
> -	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
> -		newsid = sbsec->mntpoint_sid;
> -	else if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
> -		rc = security_transition_sid(sid, dsec->sid,
> -					     inode_mode_to_security_class(inode->i_mode),
> -					     qstr, &newsid);
> -		if (rc) {
> -			printk(KERN_WARNING "%s:  "
> -			       "security_transition_sid failed, rc=%d (dev=%s "
> -			       "ino=%ld)\n",
> -			       __func__,
> -			       -rc, inode->i_sb->s_id, inode->i_ino);
> -			return rc;
> -		}
> -	}
> +	rc = selinux_determine_inode_label(
> +		dir, qstr,
> +		inode_mode_to_security_class(inode->i_mode),
> +		&newsid);
> +	if (rc)
> +		return rc;
>  
>  	/* Possibly defer initialization to selinux_complete_init. */
>  	if (sbsec->flags & SE_SBINITIALIZED) {
> 
> 

Re: [PATCH] SELinux: Create a common helper to determine an inode label [ver #3]

[Paul Moore]

On Thursday, June 18, 2015 07:25:05 PM David Howells wrote:
> Create a common helper function to determine the label for a new inode.
> This is then used by:
> 
> 	- may_create()
> 	- selinux_dentry_init_security()
> 	- selinux_inode_init_security()
> 
> This will change the behaviour of the functions slightly, bringing them all
> into line.
> 
> Suggested-by: Stephen Smalley <sds@tycho.nsa.gov>
> Signed-off-by: David Howells <dhowells@redhat.com>

This patch looks fine to me and I think there is an advantage to merging this 
regardless of what happens with the "unioning" work so I'm inclined to queue 
this up now unless you would prefer to resubmit with the union patches?

> ---
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index ffa5a642629a..ec30e599fb46 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -1684,6 +1684,32 @@ out:
>  	return rc;
>  }
> 
> +/*
> + * Determine the label for an inode that might be unioned.
> + */
> +static int selinux_determine_inode_label(const struct inode *dir,
> +					 const struct qstr *name,
> +					 u16 tclass,
> +					 u32 *_new_isid)
> +{
> +	const struct superblock_security_struct *sbsec = dir->i_sb->s_security;
> +	const struct inode_security_struct *dsec = dir->i_security;
> +	const struct task_security_struct *tsec = current_security();
> +
> +	if ((sbsec->flags & SE_SBINITIALIZED) &&
> +	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
> +		*_new_isid = sbsec->mntpoint_sid;
> +	} else if ((sbsec->flags & SBLABEL_MNT) &&
> +		   tsec->create_sid) {
> +		*_new_isid = tsec->create_sid;
> +	} else {
> +		return security_transition_sid(tsec->sid, dsec->sid, tclass,
> +					       name, _new_isid);
> +	}
> +
> +	return 0;
> +}
> +
>  /* Check whether a task can create a file. */
>  static int may_create(struct inode *dir,
>  		      struct dentry *dentry,
> @@ -1700,7 +1726,6 @@ static int may_create(struct inode *dir,
>  	sbsec = dir->i_sb->s_security;
> 
>  	sid = tsec->sid;
> -	newsid = tsec->create_sid;
> 
>  	ad.type = LSM_AUDIT_DATA_DENTRY;
>  	ad.u.dentry = dentry;
> @@ -1711,12 +1736,10 @@ static int may_create(struct inode *dir,
>  	if (rc)
>  		return rc;
> 
> -	if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
> -		rc = security_transition_sid(sid, dsec->sid, tclass,
> -					     &dentry->d_name, &newsid);
> -		if (rc)
> -			return rc;
> -	}
> +	rc = selinux_determine_inode_label(dir, &dentry->d_name, tclass,
> +					   &newsid);
> +	if (rc)
> +		return rc;
> 
>  	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
>  	if (rc)
> @@ -2723,32 +2746,14 @@ static int selinux_dentry_init_security(struct
> dentry *dentry, int mode, struct qstr *name, void **ctx,
>  					u32 *ctxlen)
>  {
> -	const struct cred *cred = current_cred();
> -	struct task_security_struct *tsec;
> -	struct inode_security_struct *dsec;
> -	struct superblock_security_struct *sbsec;
> -	struct inode *dir = d_backing_inode(dentry->d_parent);
>  	u32 newsid;
>  	int rc;
> 
> -	tsec = cred->security;
> -	dsec = dir->i_security;
> -	sbsec = dir->i_sb->s_security;
> -
> -	if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
> -		newsid = tsec->create_sid;
> -	} else {
> -		rc = security_transition_sid(tsec->sid, dsec->sid,
> -					     inode_mode_to_security_class(mode),
> -					     name,
> -					     &newsid);
> -		if (rc) {
> -			printk(KERN_WARNING
> -				"%s: security_transition_sid failed, rc=%d\n",
> -			       __func__, -rc);
> -			return rc;
> -		}
> -	}
> +	rc = selinux_determine_inode_label(d_inode(dentry->d_parent), name,
> +					   inode_mode_to_security_class(mode),
> +					   &newsid);
> +	if (rc)
> +		return rc;
> 
>  	return security_sid_to_context(newsid, (char **)ctx, ctxlen);
>  }
> @@ -2771,22 +2776,12 @@ static int selinux_inode_init_security(struct inode
> *inode, struct inode *dir, sid = tsec->sid;
>  	newsid = tsec->create_sid;
> 
> -	if ((sbsec->flags & SE_SBINITIALIZED) &&
> -	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
> -		newsid = sbsec->mntpoint_sid;
> -	else if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
> -		rc = security_transition_sid(sid, dsec->sid,
> -					     inode_mode_to_security_class(inode->i_mode),
> -					     qstr, &newsid);
> -		if (rc) {
> -			printk(KERN_WARNING "%s:  "
> -			       "security_transition_sid failed, rc=%d (dev=%s "
> -			       "ino=%ld)\n",
> -			       __func__,
> -			       -rc, inode->i_sb->s_id, inode->i_ino);
> -			return rc;
> -		}
> -	}
> +	rc = selinux_determine_inode_label(
> +		dir, qstr,
> +		inode_mode_to_security_class(inode->i_mode),
> +		&newsid);
> +	if (rc)
> +		return rc;
> 
>  	/* Possibly defer initialization to selinux_complete_init. */
>  	if (sbsec->flags & SE_SBINITIALIZED) {

-- 
paul moore
www.paul-moore.com

Re: [PATCH] SELinux: Create a common helper to determine an inode label [ver #3]

[Paul Moore]

On Thursday, June 18, 2015 07:25:05 PM David Howells wrote:
> Create a common helper function to determine the label for a new inode.
> This is then used by:
> 
> 	- may_create()
> 	- selinux_dentry_init_security()
> 	- selinux_inode_init_security()
> 
> This will change the behaviour of the functions slightly, bringing them all
> into line.
> 
> Suggested-by: Stephen Smalley <sds@tycho.nsa.gov>
> Signed-off-by: David Howells <dhowells@redhat.com>

This patch looks fine to me and I think there is an advantage to merging this 
regardless of what happens with the "unioning" work so I'm inclined to queue 
this up now unless you would prefer to resubmit with the union patches?

> ---
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index ffa5a642629a..ec30e599fb46 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -1684,6 +1684,32 @@ out:
>  	return rc;
>  }
> 
> +/*
> + * Determine the label for an inode that might be unioned.
> + */
> +static int selinux_determine_inode_label(const struct inode *dir,
> +					 const struct qstr *name,
> +					 u16 tclass,
> +					 u32 *_new_isid)
> +{
> +	const struct superblock_security_struct *sbsec = dir->i_sb->s_security;
> +	const struct inode_security_struct *dsec = dir->i_security;
> +	const struct task_security_struct *tsec = current_security();
> +
> +	if ((sbsec->flags & SE_SBINITIALIZED) &&
> +	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
> +		*_new_isid = sbsec->mntpoint_sid;
> +	} else if ((sbsec->flags & SBLABEL_MNT) &&
> +		   tsec->create_sid) {
> +		*_new_isid = tsec->create_sid;
> +	} else {
> +		return security_transition_sid(tsec->sid, dsec->sid, tclass,
> +					       name, _new_isid);
> +	}
> +
> +	return 0;
> +}
> +
>  /* Check whether a task can create a file. */
>  static int may_create(struct inode *dir,
>  		      struct dentry *dentry,
> @@ -1700,7 +1726,6 @@ static int may_create(struct inode *dir,
>  	sbsec = dir->i_sb->s_security;
> 
>  	sid = tsec->sid;
> -	newsid = tsec->create_sid;
> 
>  	ad.type = LSM_AUDIT_DATA_DENTRY;
>  	ad.u.dentry = dentry;
> @@ -1711,12 +1736,10 @@ static int may_create(struct inode *dir,
>  	if (rc)
>  		return rc;
> 
> -	if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
> -		rc = security_transition_sid(sid, dsec->sid, tclass,
> -					     &dentry->d_name, &newsid);
> -		if (rc)
> -			return rc;
> -	}
> +	rc = selinux_determine_inode_label(dir, &dentry->d_name, tclass,
> +					   &newsid);
> +	if (rc)
> +		return rc;
> 
>  	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
>  	if (rc)
> @@ -2723,32 +2746,14 @@ static int selinux_dentry_init_security(struct
> dentry *dentry, int mode, struct qstr *name, void **ctx,
>  					u32 *ctxlen)
>  {
> -	const struct cred *cred = current_cred();
> -	struct task_security_struct *tsec;
> -	struct inode_security_struct *dsec;
> -	struct superblock_security_struct *sbsec;
> -	struct inode *dir = d_backing_inode(dentry->d_parent);
>  	u32 newsid;
>  	int rc;
> 
> -	tsec = cred->security;
> -	dsec = dir->i_security;
> -	sbsec = dir->i_sb->s_security;
> -
> -	if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
> -		newsid = tsec->create_sid;
> -	} else {
> -		rc = security_transition_sid(tsec->sid, dsec->sid,
> -					     inode_mode_to_security_class(mode),
> -					     name,
> -					     &newsid);
> -		if (rc) {
> -			printk(KERN_WARNING
> -				"%s: security_transition_sid failed, rc=%d\n",
> -			       __func__, -rc);
> -			return rc;
> -		}
> -	}
> +	rc = selinux_determine_inode_label(d_inode(dentry->d_parent), name,
> +					   inode_mode_to_security_class(mode),
> +					   &newsid);
> +	if (rc)
> +		return rc;
> 
>  	return security_sid_to_context(newsid, (char **)ctx, ctxlen);
>  }
> @@ -2771,22 +2776,12 @@ static int selinux_inode_init_security(struct inode
> *inode, struct inode *dir, sid = tsec->sid;
>  	newsid = tsec->create_sid;
> 
> -	if ((sbsec->flags & SE_SBINITIALIZED) &&
> -	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
> -		newsid = sbsec->mntpoint_sid;
> -	else if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
> -		rc = security_transition_sid(sid, dsec->sid,
> -					     inode_mode_to_security_class(inode->i_mode),
> -					     qstr, &newsid);
> -		if (rc) {
> -			printk(KERN_WARNING "%s:  "
> -			       "security_transition_sid failed, rc=%d (dev=%s "
> -			       "ino=%ld)\n",
> -			       __func__,
> -			       -rc, inode->i_sb->s_id, inode->i_ino);
> -			return rc;
> -		}
> -	}
> +	rc = selinux_determine_inode_label(
> +		dir, qstr,
> +		inode_mode_to_security_class(inode->i_mode),
> +		&newsid);
> +	if (rc)
> +		return rc;
> 
>  	/* Possibly defer initialization to selinux_complete_init. */
>  	if (sbsec->flags & SE_SBINITIALIZED) {

-- 
paul moore
www.paul-moore.com

Re: [PATCH] SELinux: Create a common helper to determine an inode label [ver #3]

[David Howells]

Paul Moore <paul@paul-moore.com> wrote:

> This patch looks fine to me and I think there is an advantage to merging this 
> regardless of what happens with the "unioning" work so I'm inclined to queue 
> this up now unless you would prefer to resubmit with the union patches?

If you could queue it up now, that'd be great!

David

Re: [PATCH] SELinux: Create a common helper to determine an inode label [ver #3]

[David Howells]

Paul Moore <paul@paul-moore.com> wrote:

> This patch looks fine to me and I think there is an advantage to merging this 
> regardless of what happens with the "unioning" work so I'm inclined to queue 
> this up now unless you would prefer to resubmit with the union patches?

If you could queue it up now, that'd be great!

David
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Re: [PATCH] SELinux: Create a common helper to determine an inode label [ver #3]

[David Howells]

Paul Moore <paul@paul-moore.com> wrote:

> This patch looks fine to me and I think there is an advantage to merging this 
> regardless of what happens with the "unioning" work so I'm inclined to queue 
> this up now unless you would prefer to resubmit with the union patches?

If you could queue it up now, that'd be great!

David

libselinux equivalent of restorecon -F

[Dominick Grift]

[-- Attachment #1: Type: text/plain, Size: 527 bytes --]

Please excuse my ignorance, and please bear with me for a moment:

I would consider lsetfilecon() functionality roughly the same to that of "restorecon" (in a sense at least).

Which libselinux interface would be provide roughly the same functionality to that of "restorecon -F" (in a sense at least) ?

Is that what selinux_lsetfilecon_default() is for?

Thanks

-- 
02DFF788
4D30 903A 1CF3 B756 FB48  1514 3148 83A2 02DF F788
http://keys.gnupg.net/pks/lookup?op=vindex&search=0x314883A202DFF788
Dominick Grift

[-- Attachment #2: Type: application/pgp-signature, Size: 648 bytes --]

Re: libselinux equivalent of restorecon -F

[Stephen Smalley]

On 06/22/2015 08:13 AM, Dominick Grift wrote:
> Please excuse my ignorance, and please bear with me for a moment:
> 
> I would consider lsetfilecon() functionality roughly the same to that of "restorecon" (in a sense at least).
> 
> Which libselinux interface would be provide roughly the same functionality to that of "restorecon -F" (in a sense at least) ?
> 
> Is that what selinux_lsetfilecon_default() is for?

Yes, that's probably the closest equivalent in upstream libselinux.
However, in Android libselinux [1], we have a
selinux_android_restorecon() function that fully replicates restorecon
functionality.  We should likely take a version of that to upstream
libselinux.  Interface is:
#define SELINUX_ANDROID_RESTORECON_NOCHANGE 1
#define SELINUX_ANDROID_RESTORECON_VERBOSE  2
#define SELINUX_ANDROID_RESTORECON_RECURSE  4
#define SELINUX_ANDROID_RESTORECON_FORCE    8
#define SELINUX_ANDROID_RESTORECON_DATADATA 16
extern int selinux_android_restorecon(const char *file, unsigned int flags);

[1] https://android.googlesource.com/platform/external/libselinux

Re: [PATCH] SELinux: Create a common helper to determine an inode label [ver #3]

[Paul Moore]

On Mon, Jun 22, 2015 at 5:41 AM, David Howells <dhowells@redhat.com> wrote:
> Paul Moore <paul@paul-moore.com> wrote:
>
>> This patch looks fine to me and I think there is an advantage to merging this
>> regardless of what happens with the "unioning" work so I'm inclined to queue
>> this up now unless you would prefer to resubmit with the union patches?
>
> If you could queue it up now, that'd be great!

All set.  As soon as the merge window closes I'll push it to the
selinux#next branch.

-- 
paul moore
www.paul-moore.com
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Re: [PATCH] SELinux: Create a common helper to determine an inode label [ver #3]

[Paul Moore]

On Mon, Jun 22, 2015 at 5:41 AM, David Howells <dhowells@redhat.com> wrote:
> Paul Moore <paul@paul-moore.com> wrote:
>
>> This patch looks fine to me and I think there is an advantage to merging this
>> regardless of what happens with the "unioning" work so I'm inclined to queue
>> this up now unless you would prefer to resubmit with the union patches?
>
> If you could queue it up now, that'd be great!

All set.  As soon as the merge window closes I'll push it to the
selinux#next branch.

-- 
paul moore
www.paul-moore.com
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Re: [PATCH] SELinux: Create a common helper to determine an inode label [ver #3]

[Paul Moore]

On Mon, Jun 22, 2015 at 5:41 AM, David Howells <dhowells@redhat.com> wrote:
> Paul Moore <paul@paul-moore.com> wrote:
>
>> This patch looks fine to me and I think there is an advantage to merging this
>> regardless of what happens with the "unioning" work so I'm inclined to queue
>> this up now unless you would prefer to resubmit with the union patches?
>
> If you could queue it up now, that'd be great!

All set.  As soon as the merge window closes I'll push it to the
selinux#next branch.

-- 
paul moore
www.paul-moore.com