commit 85d7266a7273f962f40987c5e07370c5e7dc0c72
author Christopher Ferris <cferris@google.com> Fri Oct 08 12:05:31 2021 -0700
committer Kelvin Zhang <zhangkelvin@google.com> Tue Oct 12 00:29:20 2021 +0000
tree d29110f02a00665a9296772627d02f532c5ff41b
parent 76eeeea93884a621bf90927437b64fc5867a9abd

Do not write past end of inotify event structure.

Bug: 202159709

Test: None yet.
Change-Id: If80ed957aaa93c03a97b57e818e7783fa6e38242
(cherry picked from commit ce87c786116557e89f9da95f550d6816aeaca67e)

minui/events.cpp

diff --git a/minui/events.cpp b/minui/events.cpp
index 87f8112..863ac74 100644
--- a/minui/events.cpp
+++ b/minui/events.cpp
@@ -29,7 +29,9 @@
 
 #include <functional>
 #include <memory>
+#include <string>
 
+#include <android-base/strings.h>
 #include <android-base/unique_fd.h>
 
 #include "minui/minui.h"
@@ -118,12 +120,12 @@
     }
     offset += sizeof(inotify_event) + pevent->len;
 
-    pevent->name[pevent->len] = '\0';
-    if (strncmp(pevent->name, "event", 5)) {
+    std::string event_name(pevent->name, pevent->len);
+    if (!android::base::StartsWith(event_name, "event")) {
       continue;
     }
 
-    android::base::unique_fd dfd(openat(dirfd(dir.get()), pevent->name, O_RDONLY));
+    android::base::unique_fd dfd(openat(dirfd(dir.get()), event_name.c_str(), O_RDONLY));
     if (dfd == -1) {
       break;
     }