Fix bug #10010 - Missing integer wrap protection in EA list reading can cause server...

Ensure we never wrap whilst adding client provided input.
CVE-2013-4124

Signed-off-by: Jeremy Allison <jra@samba.org>
(cherry picked from commit efdbcabbe97a594572d71d714d258a5854c5d8ce)

diff --git a/source3/smbd/nttrans.c b/source3/smbd/nttrans.c
index ea9d417e7438b355eca627dc12305b4708c43754..5fc3a09784d86b734253b49e8512a42c3bcc1463 100644 (file)
--- a/source3/smbd/nttrans.c
+++ b/source3/smbd/nttrans.c
@@ -989,7 +989,19 @@ struct ea_list *read_nttrans_ea_list(TALLOC_CTX *ctx, const char *pdata, size_t
                if (next_offset == 0) {
                        break;
                }
+
+               /* Integer wrap protection for the increment. */
+               if (offset + next_offset < offset) {
+                       break;
+               }
+
                offset += next_offset;
+
+               /* Integer wrap protection for while loop. */
+               if (offset + 4 < offset) {
+                       break;
+               }
+
        }
 
        return ea_list_head;