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Commit 99313414 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs 

Pull overlayfs fixes from Miklos Szeredi:
 "This fixes a crash with SELinux and several other old and new bugs"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: check for bad and whiteout index on lookup
  ovl: do not cleanup directory and whiteout index entries
  ovl: fix xattr get and set with selinux
  ovl: remove unneeded check for IS_ERR()
  ovl: fix origin verification of index dir
  ovl: mark parent impure on ovl_link()
  ovl: fix random return value on mount
parents 0151ef00 0e082555

fs/overlayfs/dir.c

+18 −4
Original line number Diff line number Diff line
@@ -481,17 +481,30 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, 
}



static int ovl_create_or_link(struct dentry *dentry, struct inode *inode,

			      struct cattr *attr, struct dentry *hardlink)

			      struct cattr *attr, struct dentry *hardlink,

			      bool origin)

{

	int err;

	const struct cred *old_cred;

	struct cred *override_cred;

	struct dentry *parent = dentry->d_parent;



	err = ovl_copy_up(dentry->d_parent);

	err = ovl_copy_up(parent);

	if (err)

		return err;



	old_cred = ovl_override_creds(dentry->d_sb);



	/*

	 * When linking a file with copy up origin into a new parent, mark the

	 * new parent dir "impure".

	 */

	if (origin) {

		err = ovl_set_impure(parent, ovl_dentry_upper(parent));

		if (err)

			goto out_revert_creds;

	}



	err = -ENOMEM;

	override_cred = prepare_creds();

	if (override_cred) {
@@ -550,7 +563,7 @@ static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev, 
	inode_init_owner(inode, dentry->d_parent->d_inode, mode);

	attr.mode = inode->i_mode;



	err = ovl_create_or_link(dentry, inode, &attr, NULL);

	err = ovl_create_or_link(dentry, inode, &attr, NULL, false);

	if (err)

		iput(inode);
@@ -609,7 +622,8 @@ static int ovl_link(struct dentry *old, struct inode *newdir, 
	inode = d_inode(old);

	ihold(inode);



	err = ovl_create_or_link(new, inode, NULL, ovl_dentry_upper(old));

	err = ovl_create_or_link(new, inode, NULL, ovl_dentry_upper(old),

				 ovl_type_origin(old));

	if (err)

		iput(inode);

fs/overlayfs/inode.c

+17 −15
Original line number Diff line number Diff line
@@ -202,37 +202,38 @@ bool ovl_is_private_xattr(const char *name) 
		       sizeof(OVL_XATTR_PREFIX) - 1) == 0;

}



int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value,

		  size_t size, int flags)

int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,

		  const void *value, size_t size, int flags)

{

	int err;

	struct path realpath;

	enum ovl_path_type type = ovl_path_real(dentry, &realpath);

	struct dentry *upperdentry = ovl_i_dentry_upper(inode);

	struct dentry *realdentry = upperdentry ?: ovl_dentry_lower(dentry);

	const struct cred *old_cred;



	err = ovl_want_write(dentry);

	if (err)

		goto out;



	if (!value && !OVL_TYPE_UPPER(type)) {

		err = vfs_getxattr(realpath.dentry, name, NULL, 0);

	if (!value && !upperdentry) {

		err = vfs_getxattr(realdentry, name, NULL, 0);

		if (err < 0)

			goto out_drop_write;

	}



	if (!upperdentry) {

		err = ovl_copy_up(dentry);

		if (err)

			goto out_drop_write;



	if (!OVL_TYPE_UPPER(type))

		ovl_path_upper(dentry, &realpath);

		realdentry = ovl_dentry_upper(dentry);

	}



	old_cred = ovl_override_creds(dentry->d_sb);

	if (value)

		err = vfs_setxattr(realpath.dentry, name, value, size, flags);

		err = vfs_setxattr(realdentry, name, value, size, flags);

	else {

		WARN_ON(flags != XATTR_REPLACE);

		err = vfs_removexattr(realpath.dentry, name);

		err = vfs_removexattr(realdentry, name);

	}

	revert_creds(old_cred);
@@ -242,12 +243,13 @@ int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value, 
	return err;

}



int ovl_xattr_get(struct dentry *dentry, const char *name,

int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,

		  void *value, size_t size)

{

	struct dentry *realdentry = ovl_dentry_real(dentry);

	ssize_t res;

	const struct cred *old_cred;

	struct dentry *realdentry =

		ovl_i_dentry_upper(inode) ?: ovl_dentry_lower(dentry);



	old_cred = ovl_override_creds(dentry->d_sb);

	res = vfs_getxattr(realdentry, name, value, size);

fs/overlayfs/namei.c

+32 −9
Original line number Diff line number Diff line
@@ -397,8 +397,19 @@ int ovl_verify_index(struct dentry *index, struct path *lowerstack, 
	if (!d_inode(index))

		return 0;



	err = -EISDIR;

	if (d_is_dir(index))

	/*

	 * Directory index entries are going to be used for looking up

	 * redirected upper dirs by lower dir fh when decoding an overlay

	 * file handle of a merge dir. Whiteout index entries are going to be

	 * used as an indication that an exported overlay file handle should

	 * be treated as stale (i.e. after unlink of the overlay inode).

	 * We don't know the verification rules for directory and whiteout

	 * index entries, because they have not been implemented yet, so return

	 * EROFS if those entries are found to avoid corrupting an index that

	 * was created by a newer kernel.

	 */

	err = -EROFS;

	if (d_is_dir(index) || ovl_is_whiteout(index))

		goto fail;



	err = -EINVAL;
@@ -436,8 +447,8 @@ int ovl_verify_index(struct dentry *index, struct path *lowerstack, 
	return err;



fail:

	pr_warn_ratelimited("overlayfs: failed to verify index (%pd2, err=%i)\n",

			    index, err);

	pr_warn_ratelimited("overlayfs: failed to verify index (%pd2, ftype=%x, err=%i)\n",

			    index, d_inode(index)->i_mode & S_IFMT, err);

	goto out;

}
@@ -502,6 +513,7 @@ static struct dentry *ovl_lookup_index(struct dentry *dentry, 
		goto out;

	}



	inode = d_inode(index);

	if (d_is_negative(index)) {

		if (upper && d_inode(origin)->i_nlink > 1) {

			pr_warn_ratelimited("overlayfs: hard link with origin but no index (ino=%lu).\n",
@@ -511,11 +523,22 @@ static struct dentry *ovl_lookup_index(struct dentry *dentry, 


		dput(index);

		index = NULL;

	} else if (upper && d_inode(index) != d_inode(upper)) {

		inode = d_inode(index);

		pr_warn_ratelimited("overlayfs: wrong index found (index ino: %lu, upper ino: %lu).\n",

				    d_inode(index)->i_ino,

				    d_inode(upper)->i_ino);

	} else if (upper && d_inode(upper) != inode) {

		pr_warn_ratelimited("overlayfs: wrong index found (index=%pd2, ino=%lu, upper ino=%lu).\n",

				    index, inode->i_ino, d_inode(upper)->i_ino);

		goto fail;

	} else if (ovl_dentry_weird(index) || ovl_is_whiteout(index) ||

		   ((inode->i_mode ^ d_inode(origin)->i_mode) & S_IFMT)) {

		/*

		 * Index should always be of the same file type as origin

		 * except for the case of a whiteout index. A whiteout

		 * index should only exist if all lower aliases have been

		 * unlinked, which means that finding a lower origin on lookup

		 * whose index is a whiteout should be treated as an error.

		 */

		pr_warn_ratelimited("overlayfs: bad index found (index=%pd2, ftype=%x, origin ftype=%x).\n",

				    index, d_inode(index)->i_mode & S_IFMT,

				    d_inode(origin)->i_mode & S_IFMT);

		goto fail;

	}

fs/overlayfs/overlayfs.h

+6 −4
Original line number Diff line number Diff line
@@ -47,7 +47,8 @@ enum ovl_flag { 
/* Is the real inode encoded in fid an upper inode? */

#define OVL_FH_FLAG_PATH_UPPER	(1 << 2)



#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN)

#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \

			 OVL_FH_FLAG_PATH_UPPER)



#if defined(__LITTLE_ENDIAN)

#define OVL_FH_FLAG_CPU_ENDIAN 0
@@ -199,6 +200,7 @@ enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); 
struct dentry *ovl_dentry_upper(struct dentry *dentry);

struct dentry *ovl_dentry_lower(struct dentry *dentry);

struct dentry *ovl_dentry_real(struct dentry *dentry);

struct dentry *ovl_i_dentry_upper(struct inode *inode);

struct inode *ovl_inode_upper(struct inode *inode);

struct inode *ovl_inode_lower(struct inode *inode);

struct inode *ovl_inode_real(struct inode *inode);
@@ -270,9 +272,9 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr); 
int ovl_getattr(const struct path *path, struct kstat *stat,

		u32 request_mask, unsigned int flags);

int ovl_permission(struct inode *inode, int mask);

int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value,

		  size_t size, int flags);

int ovl_xattr_get(struct dentry *dentry, const char *name,

int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,

		  const void *value, size_t size, int flags);

int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,

		  void *value, size_t size);

ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);

struct posix_acl *ovl_get_acl(struct inode *inode, int type);

fs/overlayfs/readdir.c

+4 −1
Original line number Diff line number Diff line
@@ -703,7 +703,10 @@ int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt, 
			err = PTR_ERR(index);

			break;

		}

		if (ovl_verify_index(index, lowerstack, numlower)) {

		err = ovl_verify_index(index, lowerstack, numlower);

		if (err) {

			if (err == -EROFS)

				break;

			err = ovl_cleanup(dir, index);

			if (err)

				break;