Merge tag 'fixes_for_v5.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull ext2 and reiserfs fixes from Jan Kara:
 "A fix for the ext2 conversion to kmap_local() and two reiserfs
  hardening fixes"

* tag 'fixes_for_v5.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  reiserfs: check directory items on read from disk
  fs/ext2: Avoid page_address on pages returned by ext2_get_page
  reiserfs: add check for root_inode in reiserfs_fill_super

Author: torvalds

fs/ext2/dir.c

@@ -106,12 +106,11 @@ static int ext2_commit_chunk(struct page *page, loff_t pos, unsigned len)
 	return err;
 }
 
-static bool ext2_check_page(struct page *page, int quiet)
+static bool ext2_check_page(struct page *page, int quiet, char *kaddr)
 {
 	struct inode *dir = page->mapping->host;
 	struct super_block *sb = dir->i_sb;
 	unsigned chunk_size = ext2_chunk_size(dir);
-	char *kaddr = page_address(page);
 	u32 max_inumber = le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count);
 	unsigned offs, rec_len;
 	unsigned limit = PAGE_SIZE;
@@ -205,7 +204,8 @@ static struct page * ext2_get_page(struct inode *dir, unsigned long n,
 	if (!IS_ERR(page)) {
 		*page_addr = kmap_local_page(page);
 		if (unlikely(!PageChecked(page))) {
-			if (PageError(page) || !ext2_check_page(page, quiet))
+			if (PageError(page) || !ext2_check_page(page, quiet,
+								*page_addr))
 				goto fail;
 		}
 	}
@@ -584,10 +584,10 @@ int ext2_add_link (struct dentry *dentry, struct inode *inode)
  * ext2_delete_entry deletes a directory entry by merging it with the
  * previous entry. Page is up-to-date.
  */
-int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page )
+int ext2_delete_entry (struct ext2_dir_entry_2 *dir, struct page *page,
+			char *kaddr)
 {
 	struct inode *inode = page->mapping->host;
-	char *kaddr = page_address(page);
 	unsigned from = ((char*)dir - kaddr) & ~(ext2_chunk_size(inode)-1);
 	unsigned to = ((char *)dir - kaddr) +
 				ext2_rec_len_from_disk(dir->rec_len);
@@ -607,7 +607,7 @@ int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page )
 		de = ext2_next_entry(de);
 	}
 	if (pde)
-		from = (char*)pde - (char*)page_address(page);
+		from = (char *)pde - kaddr;
 	pos = page_offset(page) + from;
 	lock_page(page);
 	err = ext2_prepare_chunk(page, pos, to - from);

fs/ext2/ext2.h

@@ -740,7 +740,8 @@ extern int ext2_inode_by_name(struct inode *dir,
 extern int ext2_make_empty(struct inode *, struct inode *);
 extern struct ext2_dir_entry_2 *ext2_find_entry(struct inode *, const struct qstr *,
 						struct page **, void **res_page_addr);
-extern int ext2_delete_entry (struct ext2_dir_entry_2 *, struct page *);
+extern int ext2_delete_entry(struct ext2_dir_entry_2 *dir, struct page *page,
+			     char *kaddr);
 extern int ext2_empty_dir (struct inode *);
 extern struct ext2_dir_entry_2 *ext2_dotdot(struct inode *dir, struct page **p, void **pa);
 extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, void *,

fs/ext2/namei.c

@@ -293,7 +293,7 @@ static int ext2_unlink(struct inode * dir, struct dentry *dentry)
 		goto out;
 	}
 
-	err = ext2_delete_entry (de, page);
+	err = ext2_delete_entry (de, page, page_addr);
 	ext2_put_page(page, page_addr);
 	if (err)
 		goto out;
@@ -397,7 +397,7 @@ static int ext2_rename (struct user_namespace * mnt_userns,
 	old_inode->i_ctime = current_time(old_inode);
 	mark_inode_dirty(old_inode);
 
-	ext2_delete_entry(old_de, old_page);
+	ext2_delete_entry(old_de, old_page, old_page_addr);
 
 	if (dir_de) {
 		if (old_dir != new_dir)

fs/reiserfs/stree.c

@@ -387,6 +387,24 @@ void pathrelse(struct treepath *search_path)
 	search_path->path_length = ILLEGAL_PATH_ELEMENT_OFFSET;
 }
 
+static int has_valid_deh_location(struct buffer_head *bh, struct item_head *ih)
+{
+	struct reiserfs_de_head *deh;
+	int i;
+
+	deh = B_I_DEH(bh, ih);
+	for (i = 0; i < ih_entry_count(ih); i++) {
+		if (deh_location(&deh[i]) > ih_item_len(ih)) {
+			reiserfs_warning(NULL, "reiserfs-5094",
+					 "directory entry location seems wrong %h",
+					 &deh[i]);
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
 static int is_leaf(char *buf, int blocksize, struct buffer_head *bh)
 {
 	struct block_head *blkh;
@@ -454,11 +472,14 @@ static int is_leaf(char *buf, int blocksize, struct buffer_head *bh)
 					 "(second one): %h", ih);
 			return 0;
 		}
-		if (is_direntry_le_ih(ih) && (ih_item_len(ih) < (ih_entry_count(ih) * IH_SIZE))) {
-			reiserfs_warning(NULL, "reiserfs-5093",
-					 "item entry count seems wrong %h",
-					 ih);
-			return 0;
+		if (is_direntry_le_ih(ih)) {
+			if (ih_item_len(ih) < (ih_entry_count(ih) * IH_SIZE)) {
+				reiserfs_warning(NULL, "reiserfs-5093",
+						 "item entry count seems wrong %h",
+						 ih);
+				return 0;
+			}
+			return has_valid_deh_location(bh, ih);
 		}
 		prev_location = ih_location(ih);
 	}

fs/reiserfs/super.c

@@ -2082,6 +2082,14 @@ static int reiserfs_fill_super(struct super_block *s, void *data, int silent)
 		unlock_new_inode(root_inode);
 	}
 
+	if (!S_ISDIR(root_inode->i_mode) || !inode_get_bytes(root_inode) ||
+	    !root_inode->i_size) {
+		SWARN(silent, s, "", "corrupt root inode, run fsck");
+		iput(root_inode);
+		errval = -EUCLEAN;
+		goto error;
+	}
+
 	s->s_root = d_make_root(root_inode);
 	if (!s->s_root)
 		goto error;