# HG changeset patch
# User Roman Arutyunyan <arut@nginx.com>
# Date 1541510958 -10800
# Node ID e5069816039b75b1653a4c7c2f982a1ca8d9f9af
# Parent  bddacdaaec9ef174504899f1528155f84bf60e59
Mp4: fixed reading 64-bit atoms.

Previously there was no validation for the size of a 64-bit atom
in an mp4 file.  This could lead to a CPU hog when the size is 0,
or various other problems due to integer underflow when calculating
atom data size, including segmentation fault or worker process
memory disclosure.

diff --git a/src/http/modules/ngx_http_mp4_module.c b/src/http/modules/ngx_http_mp4_module.c
--- a/src/http/modules/ngx_http_mp4_module.c
+++ b/src/http/modules/ngx_http_mp4_module.c
@@ -942,6 +942,13 @@ ngx_http_mp4_read_atom(ngx_http_mp4_file
                 atom_size = ngx_mp4_get_64value(atom_header + 8);
                 atom_header_size = sizeof(ngx_mp4_atom_header64_t);
 
+                if (atom_size < sizeof(ngx_mp4_atom_header64_t)) {
+                    ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                                  "\"%s\" mp4 atom is too small:%uL",
+                                  mp4->file.name.data, atom_size);
+                    return NGX_ERROR;
+                }
+
             } else {
                 ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
                               "\"%s\" mp4 atom is too small:%uL",