On Thu, 2 May 2013, Steve Dickson wrote:
> From: David Quigley <dpquigl@xxxxxxxxxxxxxxx>
>
> There currently doesn't exist a labeling type that is adequate for use with
> labeled NFS. Since NFS doesn't really support xattrs we can't use the use xattr
> labeling behavior. For this we developed a new labeling type. The native
> labeling type is used solely by NFS to ensure NFS inodes are labeled at runtime
> by the NFS code instead of relying on the SELinux security server on the client
> end.
>
> Signed-off-by: Matthew N. Dodd <Matthew.Dodd@xxxxxxxxxx>
> Signed-off-by: Miguel Rodel Felipe <Rodel_FM@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Phua Eu Gene <PHUA_Eu_Gene@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Khin Mi Mi Aung <Mi_Mi_AUNG@xxxxxxxxxxxxxxxxx>
Acked-by: James Morris <james.l.morris@xxxxxxxxxx>
> ---
> include/linux/security.h | 3 +++
> security/selinux/hooks.c | 35 ++++++++++++++++++++++++++---------
> security/selinux/include/security.h | 2 ++
> security/selinux/ss/policydb.c | 5 ++++-
> 4 files changed, 35 insertions(+), 10 deletions(-)
>
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 4ab51e2..bc924d7 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -61,6 +61,9 @@ struct mm_struct;
> #define SECURITY_CAP_NOAUDIT 0
> #define SECURITY_CAP_AUDIT 1
>
> +/* LSM Agnostic defines for sb_set_mnt_opts */
> +#define SECURITY_LSM_NATIVE_LABELS 1
> +
> struct ctl_table;
> struct audit_krule;
> struct user_namespace;
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 6cb24ec..d7ff806 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -81,6 +81,7 @@
> #include <linux/syslog.h>
> #include <linux/user_namespace.h>
> #include <linux/export.h>
> +#include <linux/security.h>
> #include <linux/msg.h>
> #include <linux/shm.h>
>
> @@ -284,13 +285,14 @@ static void superblock_free_security(struct super_block *sb)
>
> /* The file system's label must be initialized prior to use. */
>
> -static const char *labeling_behaviors[6] = {
> +static const char *labeling_behaviors[7] = {
> "uses xattr",
> "uses transition SIDs",
> "uses task SIDs",
> "uses genfs_contexts",
> "not configured for labeling",
> "uses mountpoint labeling",
> + "uses native labeling",
> };
>
> static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
> @@ -678,14 +680,21 @@ static int selinux_set_mnt_opts(struct super_block *sb,
> if (strcmp(sb->s_type->name, "proc") == 0)
> sbsec->flags |= SE_SBPROC;
>
> - /* Determine the labeling behavior to use for this filesystem type. */
> - rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid);
> - if (rc) {
> - printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
> - __func__, sb->s_type->name, rc);
> - goto out;
> + if (!sbsec->behavior) {
> + /*
> + * Determine the labeling behavior to use for this
> + * filesystem type.
> + */
> + rc = security_fs_use((sbsec->flags & SE_SBPROC) ?
> + "proc" : sb->s_type->name,
> + &sbsec->behavior, &sbsec->sid);
> + if (rc) {
> + printk(KERN_WARNING
> + "%s: security_fs_use(%s) returned %d\n",
> + __func__, sb->s_type->name, rc);
> + goto out;
> + }
> }
> -
> /* sets the context of the superblock for the fs being mounted. */
> if (fscontext_sid) {
> rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
> @@ -700,6 +709,11 @@ static int selinux_set_mnt_opts(struct super_block *sb,
> * sets the label used on all file below the mountpoint, and will set
> * the superblock context if not already set.
> */
> + if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
> + sbsec->behavior = SECURITY_FS_USE_NATIVE;
> + *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
> + }
> +
> if (context_sid) {
> if (!fscontext_sid) {
> rc = may_context_mount_sb_relabel(context_sid, sbsec,
> @@ -731,7 +745,8 @@ static int selinux_set_mnt_opts(struct super_block *sb,
> }
>
> if (defcontext_sid) {
> - if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
> + if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
> + sbsec->behavior != SECURITY_FS_USE_NATIVE) {
> rc = -EINVAL;
> printk(KERN_WARNING "SELinux: defcontext option is "
> "invalid for this filesystem type\n");
> @@ -1199,6 +1214,8 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
> }
>
> switch (sbsec->behavior) {
> + case SECURITY_FS_USE_NATIVE:
> + break;
> case SECURITY_FS_USE_XATTR:
> if (!inode->i_op->getxattr) {
> isec->sid = sbsec->def_sid;
> diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
> index 6d38851..8fd8e18 100644
> --- a/security/selinux/include/security.h
> +++ b/security/selinux/include/security.h
> @@ -169,6 +169,8 @@ int security_get_allow_unknown(void);
> #define SECURITY_FS_USE_GENFS 4 /* use the genfs support */
> #define SECURITY_FS_USE_NONE 5 /* no labeling support */
> #define SECURITY_FS_USE_MNTPOINT 6 /* use mountpoint labeling */
> +#define SECURITY_FS_USE_NATIVE 7 /* use native label support */
> +#define SECURITY_FS_USE_MAX 7 /* Highest SECURITY_FS_USE_XXX */
>
> int security_fs_use(const char *fstype, unsigned int *behavior,
> u32 *sid);
> diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
> index 9cd9b7c..c8adde3 100644
> --- a/security/selinux/ss/policydb.c
> +++ b/security/selinux/ss/policydb.c
> @@ -2168,7 +2168,10 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info,
>
> rc = -EINVAL;
> c->v.behavior = le32_to_cpu(buf[0]);
> - if (c->v.behavior > SECURITY_FS_USE_NONE)
> + /* Determined at runtime, not in policy DB. */
> + if (c->v.behavior == SECURITY_FS_USE_MNTPOINT)
> + goto out;
> + if (c->v.behavior > SECURITY_FS_USE_MAX)
> goto out;
>
> rc = -ENOMEM;
> --
> 1.8.1.4
>
> --
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>
--
James Morris
<jmorris@xxxxxxxxx>
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