struct inode_security_struct *isec = inode->i_security;
struct superblock_security_struct *sbsec = inode->i_sb->s_security;
- spin_lock(&sbsec->isec_lock);
- if (!list_empty(&isec->list))
+ /*
+ * As not all inode security structures are in a list, we check for
+ * empty list outside of the lock to make sure that we won't waste
+ * time taking a lock doing nothing.
+ *
+ * The list_del_init() function can be safely called more than once.
+ * It should not be possible for this function to be called with
+ * concurrent list_add(), but for better safety against future changes
+ * in the code, we use list_empty_careful() here.
+ */
+ if (!list_empty_careful(&isec->list)) {
+ spin_lock(&sbsec->isec_lock);
list_del_init(&isec->list);
- spin_unlock(&sbsec->isec_lock);
+ spin_unlock(&sbsec->isec_lock);
+ }
/*
* The inode may still be referenced in a path walk and
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,
sbsec = dir->i_sb->s_security;
sid = tsec->sid;
- newsid = tsec->create_sid;
ad.type = LSM_AUDIT_DATA_DENTRY;
ad.u.dentry = dentry;
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)
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);
}
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) {
file_free_security(file);
}
+/*
+ * Check whether a task has the ioctl permission and cmd
+ * operation to an inode.
+ */
+int ioctl_has_perm(const struct cred *cred, struct file *file,
+ u32 requested, u16 cmd)
+{
+ struct common_audit_data ad;
+ struct file_security_struct *fsec = file->f_security;
+ struct inode *inode = file_inode(file);
+ struct inode_security_struct *isec = inode->i_security;
+ struct lsm_ioctlop_audit ioctl;
+ u32 ssid = cred_sid(cred);
+ int rc;
+ u8 driver = cmd >> 8;
+ u8 xperm = cmd & 0xff;
+
+ ad.type = LSM_AUDIT_DATA_IOCTL_OP;
+ ad.u.op = &ioctl;
+ ad.u.op->cmd = cmd;
+ ad.u.op->path = file->f_path;
+
+ if (ssid != fsec->sid) {
+ rc = avc_has_perm(ssid, fsec->sid,
+ SECCLASS_FD,
+ FD__USE,
+ &ad);
+ if (rc)
+ goto out;
+ }
+
+ if (unlikely(IS_PRIVATE(inode)))
+ return 0;
+
+ rc = avc_has_extended_perms(ssid, isec->sid, isec->sclass,
+ requested, driver, xperm, &ad);
+out:
+ return rc;
+}
+
static int selinux_file_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
* to the file's ioctl() function.
*/
default:
- error = file_has_perm(cred, file, FILE__IOCTL);
+ error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
}
return error;
}
sksec->peer_sid = SECINITSID_UNLABELED;
sksec->sid = SECINITSID_UNLABELED;
+ sksec->sclass = SECCLASS_SOCKET;
selinux_netlbl_sk_security_reset(sksec);
sk->sk_security = sksec;
projects / cascardo / linux.git / blobdiff