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authorAnand Avati <avati@redhat.com>2013-04-16 18:56:19 -0400
committerEric Paris <eparis@redhat.com>2013-08-28 14:44:52 -0400
commit102aefdda4d8275ce7d7100bc16c88c74272b260 (patch)
tree808ea5ebeb04abbf5e8d9c024f261225a41420d7 /security
parent2be4d74f2fd45460d70d4fe65cc1972ef45bf849 (diff)
downloadlinux-stericsson-102aefdda4d8275ce7d7100bc16c88c74272b260.tar.gz
selinux: consider filesystem subtype in policies
Not considering sub filesystem has the following limitation. Support for SELinux in FUSE is dependent on the particular userspace filesystem, which is identified by the subtype. For e.g, GlusterFS, a FUSE based filesystem supports SELinux (by mounting and processing FUSE requests in different threads, avoiding the mount time deadlock), whereas other FUSE based filesystems (identified by a different subtype) have the mount time deadlock. By considering the subtype of the filesytem in the SELinux policies, allows us to specify a filesystem subtype, in the following way: fs_use_xattr fuse.glusterfs gen_context(system_u:object_r:fs_t,s0); This way not all FUSE filesystems are put in the same bucket and subjected to the limitations of the other subtypes. Signed-off-by: Anand Avati <avati@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com>
Diffstat (limited to 'security')
-rw-r--r--security/selinux/hooks.c40
-rw-r--r--security/selinux/ss/services.c42
2 files changed, 60 insertions, 22 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 4fbf2c5f26ce..0d4408debb45 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -94,6 +94,10 @@
#include "audit.h"
#include "avc_ss.h"
+#define SB_TYPE_FMT "%s%s%s"
+#define SB_SUBTYPE(sb) (sb->s_subtype && sb->s_subtype[0])
+#define SB_TYPE_ARGS(sb) sb->s_type->name, SB_SUBTYPE(sb) ? "." : "", SB_SUBTYPE(sb) ? sb->s_subtype : ""
+
extern struct security_operations *security_ops;
/* SECMARK reference count */
@@ -407,8 +411,8 @@ static int sb_finish_set_opts(struct super_block *sb)
the first boot of the SELinux kernel before we have
assigned xattr values to the filesystem. */
if (!root_inode->i_op->getxattr) {
- printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
- "xattr support\n", sb->s_id, sb->s_type->name);
+ printk(KERN_WARNING "SELinux: (dev %s, type "SB_TYPE_FMT") has no "
+ "xattr support\n", sb->s_id, SB_TYPE_ARGS(sb));
rc = -EOPNOTSUPP;
goto out;
}
@@ -416,22 +420,22 @@ static int sb_finish_set_opts(struct super_block *sb)
if (rc < 0 && rc != -ENODATA) {
if (rc == -EOPNOTSUPP)
printk(KERN_WARNING "SELinux: (dev %s, type "
- "%s) has no security xattr handler\n",
- sb->s_id, sb->s_type->name);
+ SB_TYPE_FMT") has no security xattr handler\n",
+ sb->s_id, SB_TYPE_ARGS(sb));
else
printk(KERN_WARNING "SELinux: (dev %s, type "
- "%s) getxattr errno %d\n", sb->s_id,
- sb->s_type->name, -rc);
+ SB_TYPE_FMT") getxattr errno %d\n", sb->s_id,
+ SB_TYPE_ARGS(sb), -rc);
goto out;
}
}
if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
- printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
- sb->s_id, sb->s_type->name);
+ printk(KERN_ERR "SELinux: initialized (dev %s, type "SB_TYPE_FMT"), unknown behavior\n",
+ sb->s_id, SB_TYPE_ARGS(sb));
else
- printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
- sb->s_id, sb->s_type->name,
+ printk(KERN_DEBUG "SELinux: initialized (dev %s, type "SB_TYPE_FMT"), %s\n",
+ sb->s_id, SB_TYPE_ARGS(sb),
labeling_behaviors[sbsec->behavior-1]);
sbsec->flags |= SE_SBINITIALIZED;
@@ -589,7 +593,6 @@ static int selinux_set_mnt_opts(struct super_block *sb,
const struct cred *cred = current_cred();
int rc = 0, i;
struct superblock_security_struct *sbsec = sb->s_security;
- const char *name = sb->s_type->name;
struct inode *inode = sbsec->sb->s_root->d_inode;
struct inode_security_struct *root_isec = inode->i_security;
u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
@@ -642,8 +645,8 @@ static int selinux_set_mnt_opts(struct super_block *sb,
strlen(mount_options[i]), &sid);
if (rc) {
printk(KERN_WARNING "SELinux: security_context_to_sid"
- "(%s) failed for (dev %s, type %s) errno=%d\n",
- mount_options[i], sb->s_id, name, rc);
+ "(%s) failed for (dev %s, type "SB_TYPE_FMT") errno=%d\n",
+ mount_options[i], sb->s_id, SB_TYPE_ARGS(sb), rc);
goto out;
}
switch (flags[i]) {
@@ -779,7 +782,8 @@ out:
out_double_mount:
rc = -EINVAL;
printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different "
- "security settings for (dev %s, type %s)\n", sb->s_id, name);
+ "security settings for (dev %s, type "SB_TYPE_FMT")\n", sb->s_id,
+ SB_TYPE_ARGS(sb));
goto out;
}
@@ -2439,8 +2443,8 @@ static int selinux_sb_remount(struct super_block *sb, void *data)
rc = security_context_to_sid(mount_options[i], len, &sid);
if (rc) {
printk(KERN_WARNING "SELinux: security_context_to_sid"
- "(%s) failed for (dev %s, type %s) errno=%d\n",
- mount_options[i], sb->s_id, sb->s_type->name, rc);
+ "(%s) failed for (dev %s, type "SB_TYPE_FMT") errno=%d\n",
+ mount_options[i], sb->s_id, SB_TYPE_ARGS(sb), rc);
goto out_free_opts;
}
rc = -EINVAL;
@@ -2478,8 +2482,8 @@ out_free_secdata:
return rc;
out_bad_option:
printk(KERN_WARNING "SELinux: unable to change security options "
- "during remount (dev %s, type=%s)\n", sb->s_id,
- sb->s_type->name);
+ "during remount (dev %s, type "SB_TYPE_FMT")\n", sb->s_id,
+ SB_TYPE_ARGS(sb));
goto out_free_opts;
}
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index d106733ad987..ee470a0b5c27 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -2334,16 +2334,50 @@ int security_fs_use(struct super_block *sb)
struct ocontext *c;
struct superblock_security_struct *sbsec = sb->s_security;
const char *fstype = sb->s_type->name;
+ const char *subtype = (sb->s_subtype && sb->s_subtype[0]) ? sb->s_subtype : NULL;
+ struct ocontext *base = NULL;
read_lock(&policy_rwlock);
- c = policydb.ocontexts[OCON_FSUSE];
- while (c) {
- if (strcmp(fstype, c->u.name) == 0)
+ for (c = policydb.ocontexts[OCON_FSUSE]; c; c = c->next) {
+ char *sub;
+ int baselen;
+
+ baselen = strlen(fstype);
+
+ /* if base does not match, this is not the one */
+ if (strncmp(fstype, c->u.name, baselen))
+ continue;
+
+ /* if there is no subtype, this is the one! */
+ if (!subtype)
+ break;
+
+ /* skip past the base in this entry */
+ sub = c->u.name + baselen;
+
+ /* entry is only a base. save it. keep looking for subtype */
+ if (sub[0] == '\0') {
+ base = c;
+ continue;
+ }
+
+ /* entry is not followed by a subtype, so it is not a match */
+ if (sub[0] != '.')
+ continue;
+
+ /* whew, we found a subtype of this fstype */
+ sub++; /* move past '.' */
+
+ /* exact match of fstype AND subtype */
+ if (!strcmp(subtype, sub))
break;
- c = c->next;
}
+ /* in case we had found an fstype match but no subtype match */
+ if (!c)
+ c = base;
+
if (c) {
sbsec->behavior = c->v.behavior;
if (!c->sid[0]) {