5 files changed, 50 insertions, 0 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 841330f3d68d..6036fdb88c53 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2393,6 +2393,9 @@ struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
                                           struct btrfs_path *path, u64 dir,
                                           const char *name, u16 name_len,
                                           int mod);
+int verify_dir_item(struct btrfs_root *root,
+                    struct extent_buffer *leaf,
+                    struct btrfs_dir_item *dir_item);
 
 /* orphan.c */
 int btrfs_insert_orphan_item(struct btrfs_trans_handle *trans,
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index f0cad5ae5be7..02c97ad61b6d 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -377,6 +377,9 @@ struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
 
         leaf = path->nodes[0];
         dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
+        if (verify_dir_item(root, leaf, dir_item))
+                return NULL;
+
         total_len = btrfs_item_size_nr(leaf, path->slots[0]);
         while (cur < total_len) {
                 this_len = sizeof(*dir_item) +
@@ -429,3 +432,35 @@ int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
         }
         return ret;
 }
+
+int verify_dir_item(struct btrfs_root *root,
+                    struct extent_buffer *leaf,
+                    struct btrfs_dir_item *dir_item)
+{
+        u16 namelen = BTRFS_NAME_LEN;
+        u8 type = btrfs_dir_type(leaf, dir_item);
+
+        if (type >= BTRFS_FT_MAX) {
+                printk(KERN_CRIT "btrfs: invalid dir item type: %d\n",
+                       (int)type);
+                return 1;
+        }
+
+        if (type == BTRFS_FT_XATTR)
+                namelen = XATTR_NAME_MAX;
+
+        if (btrfs_dir_name_len(leaf, dir_item) > namelen) {
+                printk(KERN_CRIT "btrfS: invalid dir item name len: %u\n",
+                       (unsigned)btrfs_dir_data_len(leaf, dir_item));
+                return 1;
+        }
+
+        /* BTRFS_MAX_XATTR_SIZE is the same for all dir items */
+        if (btrfs_dir_data_len(leaf, dir_item) > BTRFS_MAX_XATTR_SIZE(root)) {
+                printk(KERN_CRIT "btrfs: invalid dir item data len: %u\n",
+                       (unsigned)btrfs_dir_data_len(leaf, dir_item));
+                return 1;
+        }
+
+        return 0;
+}
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 888dbdb3b128..e010000d4bc9 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4272,6 +4272,9 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
                 while (di_cur < di_total) {
                         struct btrfs_key location;
 
+                        if (verify_dir_item(root, leaf, di))
+                                break;
+
                         name_len = btrfs_dir_name_len(leaf, di);
                         if (name_len <= sizeof(tmp_name)) {
                                 name_ptr = tmp_name;
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index a4bbb854dfd2..429cfcfadf90 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -1286,6 +1286,8 @@ static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
         ptr_end = ptr + item_size;
         while (ptr < ptr_end) {
                 di = (struct btrfs_dir_item *)ptr;
+                if (verify_dir_item(root, eb, di))
+                        return -EIO;
                 name_len = btrfs_dir_name_len(eb, di);
                 ret = replay_one_name(trans, root, path, eb, di, key);
                 BUG_ON(ret);
@@ -1412,6 +1414,11 @@ again:
         ptr_end = ptr + item_size;
         while (ptr < ptr_end) {
                 di = (struct btrfs_dir_item *)ptr;
+                if (verify_dir_item(root, eb, di)) {
+                        ret = -EIO;
+                        goto out;
+                }
+
                 name_len = btrfs_dir_name_len(eb, di);
                 name = kmalloc(name_len, GFP_NOFS);
                 if (!name) {
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index a5776531dc2b..e5d22f280956 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -242,6 +242,8 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
                         break;
 
                 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
+                if (verify_dir_item(root, leaf, di))
+                        continue;
 
                 name_len = btrfs_dir_name_len(leaf, di);
                 total_size += name_len + 1;