ocfs2: correctly check the return value of ocfs2_search_extent_list

ocfs2_search_extent_list may return -1, so we should check the return
value in ocfs2_split_and_insert, otherwise it may cause array index out of
bound.

And ocfs2_search_extent_list can only return value less than
el->l_next_free_rec, so check if it is equal or larger than
le16_to_cpu(el->l_next_free_rec) is meaningless.

Signed-off-by: Yingtai Xie <xieyingtai@huawei.com>
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 12 insertions, 3 deletions

diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index 9d8fcf2f3b94..a93bf9892256 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -4961,6 +4961,15 @@ leftright:
 
                 el = path_leaf_el(path);
                 split_index = ocfs2_search_extent_list(el, cpos);
+                if (split_index == -1) {
+                        ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
+                                        "Owner %llu has an extent at cpos %u "
+                                        "which can no longer be found.\n",
+                                        (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
+                                        cpos);
+                        ret = -EROFS;
+                        goto out;
+                }
                 goto leftright;
         }
 out:
@@ -5135,7 +5144,7 @@ int ocfs2_change_extent_flag(handle_t *handle,
         el = path_leaf_el(left_path);
 
         index = ocfs2_search_extent_list(el, cpos);
-        if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {
+        if (index == -1) {
                 ocfs2_error(sb,
                             "Owner %llu has an extent at cpos %u which can no "
                             "longer be found.\n",
@@ -5491,7 +5500,7 @@ int ocfs2_remove_extent(handle_t *handle,
 
         el = path_leaf_el(path);
         index = ocfs2_search_extent_list(el, cpos);
-        if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {
+        if (index == -1) {
                 ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
                             "Owner %llu has an extent at cpos %u which can no "
                             "longer be found.\n",
@@ -5557,7 +5566,7 @@ int ocfs2_remove_extent(handle_t *handle,
 
                 el = path_leaf_el(path);
                 index = ocfs2_search_extent_list(el, cpos);
-                if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {
+                if (index == -1) {
                         ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
                                     "Owner %llu: split at cpos %u lost record.",
                                     (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),