diff --git a/fs/ntfs3/index.c b/fs/ntfs3/index.c index 5344b29b0577..dbf5ec00b237 100644 --- a/fs/ntfs3/index.c +++ b/fs/ntfs3/index.c @@ -2022,13 +2022,21 @@ int indx_insert_entry(struct ntfs_index *indx, struct ntfs_inode *ni, static struct indx_node *indx_find_buffer(struct ntfs_index *indx, struct ntfs_inode *ni, const struct INDEX_ROOT *root, - __le64 vbn, struct indx_node *n) + __le64 vbn, struct indx_node *n, + int depth) { int err; const struct NTFS_DE *e; struct indx_node *r; const struct INDEX_HDR *hdr = n ? &n->index->ihdr : &root->ihdr; + /* + * Limit recursion depth to prevent stack overflow from crafted + * images. Use the same bound as the fnd->nodes array (20). + */ + if (depth > ARRAY_SIZE(((struct ntfs_fnd *)NULL)->nodes)) + return ERR_PTR(-EINVAL); + /* Step 1: Scan one level. */ for (e = hdr_first_de(hdr);; e = hdr_next_de(hdr, e)) { if (!e) @@ -2049,7 +2057,8 @@ static struct indx_node *indx_find_buffer(struct ntfs_index *indx, if (err) return ERR_PTR(err); - r = indx_find_buffer(indx, ni, root, vbn, n); + r = indx_find_buffer(indx, ni, root, vbn, n, + depth + 1); if (r) return r; } @@ -2462,7 +2471,7 @@ int indx_delete_entry(struct ntfs_index *indx, struct ntfs_inode *ni, fnd_clear(fnd); - in = indx_find_buffer(indx, ni, root, sub_vbn, NULL); + in = indx_find_buffer(indx, ni, root, sub_vbn, NULL, 0); if (IS_ERR(in)) { err = PTR_ERR(in); goto out;