#include <linux/evm.h>
#include <linux/ima.h>
-static bool chown_ok(const struct inode *inode, kuid_t uid)
+/**
+ * chown_ok - verify permissions to chown inode
+ * @mnt_userns: user namespace of the mount @inode was found from
+ * @inode: inode to check permissions on
+ * @uid: uid to chown @inode to
+ *
+ * If the inode has been found through an idmapped mount the user namespace of
+ * the vfsmount must be passed through @mnt_userns. This function will then
+ * take care to map the inode according to @mnt_userns before checking
+ * permissions. On non-idmapped mounts or if permission checking is to be
+ * performed on the raw inode simply passs init_user_ns.
+ */
+static bool chown_ok(struct user_namespace *mnt_userns,
+ const struct inode *inode,
+ kuid_t uid)
{
- if (uid_eq(current_fsuid(), inode->i_uid) &&
- uid_eq(uid, inode->i_uid))
+ kuid_t kuid = i_uid_into_mnt(mnt_userns, inode);
+ if (uid_eq(current_fsuid(), kuid) && uid_eq(uid, kuid))
return true;
- if (capable_wrt_inode_uidgid(inode, CAP_CHOWN))
+ if (capable_wrt_inode_uidgid(mnt_userns, inode, CAP_CHOWN))
return true;
- if (uid_eq(inode->i_uid, INVALID_UID) &&
+ if (uid_eq(kuid, INVALID_UID) &&
ns_capable(inode->i_sb->s_user_ns, CAP_CHOWN))
return true;
return false;
}
-static bool chgrp_ok(const struct inode *inode, kgid_t gid)
+/**
+ * chgrp_ok - verify permissions to chgrp inode
+ * @mnt_userns: user namespace of the mount @inode was found from
+ * @inode: inode to check permissions on
+ * @gid: gid to chown @inode to
+ *
+ * If the inode has been found through an idmapped mount the user namespace of
+ * the vfsmount must be passed through @mnt_userns. This function will then
+ * take care to map the inode according to @mnt_userns before checking
+ * permissions. On non-idmapped mounts or if permission checking is to be
+ * performed on the raw inode simply passs init_user_ns.
+ */
+static bool chgrp_ok(struct user_namespace *mnt_userns,
+ const struct inode *inode, kgid_t gid)
{
- if (uid_eq(current_fsuid(), inode->i_uid) &&
- (in_group_p(gid) || gid_eq(gid, inode->i_gid)))
+ kgid_t kgid = i_gid_into_mnt(mnt_userns, inode);
+ if (uid_eq(current_fsuid(), i_uid_into_mnt(mnt_userns, inode)) &&
+ (in_group_p(gid) || gid_eq(gid, kgid)))
return true;
- if (capable_wrt_inode_uidgid(inode, CAP_CHOWN))
+ if (capable_wrt_inode_uidgid(mnt_userns, inode, CAP_CHOWN))
return true;
- if (gid_eq(inode->i_gid, INVALID_GID) &&
+ if (gid_eq(kgid, INVALID_GID) &&
ns_capable(inode->i_sb->s_user_ns, CAP_CHOWN))
return true;
return false;
/**
* setattr_prepare - check if attribute changes to a dentry are allowed
+ * @mnt_userns: user namespace of the mount the inode was found from
* @dentry: dentry to check
* @attr: attributes to change
*
* SGID bit from mode if user is not allowed to set it. Also file capabilities
* and IMA extended attributes are cleared if ATTR_KILL_PRIV is set.
*
+ * If the inode has been found through an idmapped mount the user namespace of
+ * the vfsmount must be passed through @mnt_userns. This function will then
+ * take care to map the inode according to @mnt_userns before checking
+ * permissions. On non-idmapped mounts or if permission checking is to be
+ * performed on the raw inode simply passs init_user_ns.
+ *
* Should be called as the first thing in ->setattr implementations,
* possibly after taking additional locks.
*/
-int setattr_prepare(struct dentry *dentry, struct iattr *attr)
+int setattr_prepare(struct user_namespace *mnt_userns, struct dentry *dentry,
+ struct iattr *attr)
{
struct inode *inode = d_inode(dentry);
unsigned int ia_valid = attr->ia_valid;
goto kill_priv;
/* Make sure a caller can chown. */
- if ((ia_valid & ATTR_UID) && !chown_ok(inode, attr->ia_uid))
+ if ((ia_valid & ATTR_UID) && !chown_ok(mnt_userns, inode, attr->ia_uid))
return -EPERM;
/* Make sure caller can chgrp. */
- if ((ia_valid & ATTR_GID) && !chgrp_ok(inode, attr->ia_gid))
+ if ((ia_valid & ATTR_GID) && !chgrp_ok(mnt_userns, inode, attr->ia_gid))
return -EPERM;
/* Make sure a caller can chmod. */
if (ia_valid & ATTR_MODE) {
- if (!inode_owner_or_capable(inode))
+ if (!inode_owner_or_capable(mnt_userns, inode))
return -EPERM;
/* Also check the setgid bit! */
- if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid :
- inode->i_gid) &&
- !capable_wrt_inode_uidgid(inode, CAP_FSETID))
+ if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid :
+ i_gid_into_mnt(mnt_userns, inode)) &&
+ !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID))
attr->ia_mode &= ~S_ISGID;
}
/* Check for setting the inode time. */
if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) {
- if (!inode_owner_or_capable(inode))
+ if (!inode_owner_or_capable(mnt_userns, inode))
return -EPERM;
}
if (ia_valid & ATTR_KILL_PRIV) {
int error;
- error = security_inode_killpriv(dentry);
+ error = security_inode_killpriv(mnt_userns, dentry);
if (error)
return error;
}
/**
* setattr_copy - copy simple metadata updates into the generic inode
+ * @mnt_userns: user namespace of the mount the inode was found from
* @inode: the inode to be updated
* @attr: the new attributes
*
* setattr_copy must be called with i_mutex held.
*
* setattr_copy updates the inode's metadata with that specified
- * in attr. Noticeably missing is inode size update, which is more complex
+ * in attr on idmapped mounts. If file ownership is changed setattr_copy
+ * doesn't map ia_uid and ia_gid. It will asssume the caller has already
+ * provided the intended values. Necessary permission checks to determine
+ * whether or not the S_ISGID property needs to be removed are performed with
+ * the correct idmapped mount permission helpers.
+ * Noticeably missing is inode size update, which is more complex
* as it requires pagecache updates.
*
+ * If the inode has been found through an idmapped mount the user namespace of
+ * the vfsmount must be passed through @mnt_userns. This function will then
+ * take care to map the inode according to @mnt_userns before checking
+ * permissions. On non-idmapped mounts or if permission checking is to be
+ * performed on the raw inode simply passs init_user_ns.
+ *
* The inode is not marked as dirty after this operation. The rationale is
* that for "simple" filesystems, the struct inode is the inode storage.
* The caller is free to mark the inode dirty afterwards if needed.
*/
-void setattr_copy(struct inode *inode, const struct iattr *attr)
+void setattr_copy(struct user_namespace *mnt_userns, struct inode *inode,
+ const struct iattr *attr)
{
unsigned int ia_valid = attr->ia_valid;
inode->i_ctime = attr->ia_ctime;
if (ia_valid & ATTR_MODE) {
umode_t mode = attr->ia_mode;
-
- if (!in_group_p(inode->i_gid) &&
- !capable_wrt_inode_uidgid(inode, CAP_FSETID))
+ kgid_t kgid = i_gid_into_mnt(mnt_userns, inode);
+ if (!in_group_p(kgid) &&
+ !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID))
mode &= ~S_ISGID;
inode->i_mode = mode;
}
/**
* notify_change - modify attributes of a filesytem object
+ * @mnt_userns: user namespace of the mount the inode was found from
* @dentry: object affected
* @attr: new attributes
* @delegated_inode: returns inode, if the inode is delegated
* retry. Because breaking a delegation may take a long time, the
* caller should drop the i_mutex before doing so.
*
+ * If file ownership is changed notify_change() doesn't map ia_uid and
+ * ia_gid. It will asssume the caller has already provided the intended values.
+ *
* Alternatively, a caller may pass NULL for delegated_inode. This may
* be appropriate for callers that expect the underlying filesystem not
* to be NFS exported. Also, passing NULL is fine for callers holding
* the file open for write, as there can be no conflicting delegation in
* that case.
+ *
+ * If the inode has been found through an idmapped mount the user namespace of
+ * the vfsmount must be passed through @mnt_userns. This function will then
+ * take care to map the inode according to @mnt_userns before checking
+ * permissions. On non-idmapped mounts or if permission checking is to be
+ * performed on the raw inode simply passs init_user_ns.
*/
-int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **delegated_inode)
+int notify_change(struct user_namespace *mnt_userns, struct dentry *dentry,
+ struct iattr *attr, struct inode **delegated_inode)
{
struct inode *inode = dentry->d_inode;
umode_t mode = inode->i_mode;
if (IS_IMMUTABLE(inode))
return -EPERM;
- if (!inode_owner_or_capable(inode)) {
- error = inode_permission(inode, MAY_WRITE);
+ if (!inode_owner_or_capable(mnt_userns, inode)) {
+ error = inode_permission(mnt_userns, inode, MAY_WRITE);
if (error)
return error;
}
/* Don't allow modifications of files with invalid uids or
* gids unless those uids & gids are being made valid.
*/
- if (!(ia_valid & ATTR_UID) && !uid_valid(inode->i_uid))
+ if (!(ia_valid & ATTR_UID) &&
+ !uid_valid(i_uid_into_mnt(mnt_userns, inode)))
return -EOVERFLOW;
- if (!(ia_valid & ATTR_GID) && !gid_valid(inode->i_gid))
+ if (!(ia_valid & ATTR_GID) &&
+ !gid_valid(i_gid_into_mnt(mnt_userns, inode)))
return -EOVERFLOW;
error = security_inode_setattr(dentry, attr);
return error;
if (inode->i_op->setattr)
- error = inode->i_op->setattr(dentry, attr);
+ error = inode->i_op->setattr(mnt_userns, dentry, attr);
else
- error = simple_setattr(dentry, attr);
+ error = simple_setattr(mnt_userns, dentry, attr);
if (!error) {
fsnotify_change(dentry, ia_valid);
- ima_inode_post_setattr(dentry);
+ ima_inode_post_setattr(mnt_userns, dentry);
evm_inode_post_setattr(dentry, ia_valid);
}
projects / linux-2.6-microblaze.git / blobdiff