diff --git a/security/sandbox/chromium/sandbox/win/src/filesystem_interception.cc b/security/sandbox/chromium/sandbox/win/src/filesystem_interception.cc
index f39333d54ef9..933e152f821e 100644
--- a/security/sandbox/chromium/sandbox/win/src/filesystem_interception.cc
+++ b/security/sandbox/chromium/sandbox/win/src/filesystem_interception.cc
@@ -16,6 +16,10 @@
 #include "sandbox/win/src/target_services.h"
 #include "mozilla/sandboxing/sandboxLogging.h"
 
+// This status occurs when trying to access a network share on the machine from
+// which it is shared.
+#define STATUS_NETWORK_OPEN_RESTRICTION ((NTSTATUS)0xC0000201L)
+
 namespace sandbox {
 
 NTSTATUS WINAPI TargetNtCreateFile(NtCreateFileFunction orig_CreateFile,
@@ -31,7 +35,8 @@ NTSTATUS WINAPI TargetNtCreateFile(NtCreateFileFunction orig_CreateFile,
                                     io_status, allocation_size,
                                     file_attributes, sharing, disposition,
                                     options, ea_buffer, ea_length);
-  if (STATUS_ACCESS_DENIED != status)
+  if (STATUS_ACCESS_DENIED != status &&
+      STATUS_NETWORK_OPEN_RESTRICTION != status)
     return status;
 
   mozilla::sandboxing::LogBlocked("NtCreateFile",
@@ -111,7 +116,8 @@ NTSTATUS WINAPI TargetNtOpenFile(NtOpenFileFunction orig_OpenFile, PHANDLE file,
   // Check if the process can open it first.
   NTSTATUS status = orig_OpenFile(file, desired_access, object_attributes,
                                   io_status, sharing, options);
-  if (STATUS_ACCESS_DENIED != status)
+  if (STATUS_ACCESS_DENIED != status &&
+      STATUS_NETWORK_OPEN_RESTRICTION != status)
     return status;
 
   mozilla::sandboxing::LogBlocked("NtOpenFile",
@@ -187,7 +193,8 @@ NTSTATUS WINAPI TargetNtQueryAttributesFile(
     PFILE_BASIC_INFORMATION file_attributes) {
   // Check if the process can query it first.
   NTSTATUS status = orig_QueryAttributes(object_attributes, file_attributes);
-  if (STATUS_ACCESS_DENIED != status)
+  if (STATUS_ACCESS_DENIED != status &&
+      STATUS_NETWORK_OPEN_RESTRICTION != status)
     return status;
 
   mozilla::sandboxing::LogBlocked("NtQueryAttributesFile",
@@ -249,7 +256,8 @@ NTSTATUS WINAPI TargetNtQueryFullAttributesFile(
   // Check if the process can query it first.
   NTSTATUS status = orig_QueryFullAttributes(object_attributes,
                                              file_attributes);
-  if (STATUS_ACCESS_DENIED != status)
+  if (STATUS_ACCESS_DENIED != status &&
+      STATUS_NETWORK_OPEN_RESTRICTION != status)
     return status;
 
   mozilla::sandboxing::LogBlocked("NtQueryFullAttributesFile",
diff --git a/security/sandbox/chromium/sandbox/win/src/filesystem_policy.cc b/security/sandbox/chromium/sandbox/win/src/filesystem_policy.cc
index fe7f62fc245e..9aa193e78407 100644
--- a/security/sandbox/chromium/sandbox/win/src/filesystem_policy.cc
+++ b/security/sandbox/chromium/sandbox/win/src/filesystem_policy.cc
@@ -82,7 +82,11 @@ bool FileSystemPolicy::GenerateRules(const wchar_t* name,
     return false;
   }
 
-  if (!PreProcessName(&mod_name)) {
+  // Don't pre-process the path name and check for reparse points if it is the
+  // special case of allowing read access to all paths.
+  if (!(semantics == TargetPolicy::FILES_ALLOW_READONLY
+        && mod_name.compare(L"*") == 0)
+      && !PreProcessName(&mod_name)) {
     // The path to be added might contain a reparse point.
     NOTREACHED();
     return false;
diff --git a/security/sandbox/modifications-to-chromium-to-reapply-after-upstream-merge.txt b/security/sandbox/modifications-to-chromium-to-reapply-after-upstream-merge.txt
index a59cb56bb244..d6cba93dc752 100644
--- a/security/sandbox/modifications-to-chromium-to-reapply-after-upstream-merge.txt
+++ b/security/sandbox/modifications-to-chromium-to-reapply-after-upstream-merge.txt
@@ -5,4 +5,5 @@ https://hg.mozilla.org/mozilla-central/rev/a05726163a79
 https://hg.mozilla.org/mozilla-central/rev/e834e810a3fa
 https://hg.mozilla.org/mozilla-central/rev/c70d06fa5302
 https://hg.mozilla.org/mozilla-central/rev/d24db55deb85
-https://bugzilla.mozilla.org/show_bug.cgi?id=1321724 bug1321724.patch
+https://hg.mozilla.org/mozilla-central/rev/0e6bf137521e
+https://bugzilla.mozilla.org/show_bug.cgi?id=1344453 bug1344453part1.patch