diff --git a/dom/quota/ActorsParent.cpp b/dom/quota/ActorsParent.cpp
index 84e32fabae0e..9aa5b3ffc1c2 100644
--- a/dom/quota/ActorsParent.cpp
+++ b/dom/quota/ActorsParent.cpp
@@ -2697,14 +2697,28 @@ Result<uint64_t, nsresult> GetTemporaryStorageLimit(nsIFile& aStorageDir) {
            1024;
   }
 
-  // Check for disk capacity of user's device on which storage directory lives.
-  QM_TRY_INSPECT(const int64_t& diskCapacity,
-                 MOZ_TO_RESULT_INVOKE_MEMBER(aStorageDir, GetDiskCapacity));
+  constexpr int64_t teraByte = (1024LL * 1024LL * 1024LL * 1024LL);
+  constexpr int64_t maxAllowedCapacity = 8LL * teraByte;
 
-  MOZ_ASSERT(diskCapacity >= 0);
+  // Check for disk capacity of user's device on which storage directory lives.
+  int64_t diskCapacity = maxAllowedCapacity;
+
+  // Log error when default disk capacity is returned due to the error
+  QM_WARNONLY_TRY(MOZ_TO_RESULT(aStorageDir.GetDiskCapacity(&diskCapacity)));
+
+  MOZ_ASSERT(diskCapacity >= 0LL);
 
   // Allow temporary storage to consume up to 50% of disk capacity.
-  return diskCapacity / 2u;
+  int64_t capacityLimit = diskCapacity / 2LL;
+
+  // If the disk capacity reported by the operating system is very
+  // large and potentially incorrect due to hardware issues,
+  // a hardcoded limit is supplied instead.
+  QM_WARNONLY_TRY(
+      OkIf(capacityLimit < maxAllowedCapacity),
+      ([&capacityLimit](const auto&) { capacityLimit = maxAllowedCapacity; }));
+
+  return capacityLimit;
 }
 
 bool IsOriginUnaccessed(const FullOriginMetadata& aFullOriginMetadata,
diff --git a/xpcom/io/nsLocalFileUnix.cpp b/xpcom/io/nsLocalFileUnix.cpp
index 321f3a1ff9e7..e88565d5659f 100644
--- a/xpcom/io/nsLocalFileUnix.cpp
+++ b/xpcom/io/nsLocalFileUnix.cpp
@@ -1492,14 +1492,11 @@ nsresult nsLocalFile::GetDiskInfo(StatInfoFunc&& aStatInfoFunc,
 
   checkedResult = std::forward<StatInfoFunc>(aStatInfoFunc)(fs_buf);
   if (!checkedResult.isValid()) {
-    return NS_ERROR_FAILURE;
+    return NS_ERROR_CANNOT_CONVERT_DATA;
   }
 
-  *aResult = checkedResult.value();
-
-#  ifdef DEBUG_DISK_SPACE
-  printf("DiskInfo: %lu bytes\n", *aResult);
-#  endif
+  // If we return an error, *aValue will not be modified.
+  int64_t tentativeResult = checkedResult.value();
 
 #  if defined(USE_LINUX_QUOTACTL)
 
@@ -1523,15 +1520,21 @@ nsresult nsLocalFile::GetDiskInfo(StatInfoFunc&& aStatInfoFunc,
       && dq.dqb_bhardlimit) {
     checkedResult = std::forward<QuotaInfoFunc>(aQuotaInfoFunc)(dq);
     if (!checkedResult.isValid()) {
-      return NS_ERROR_FAILURE;
+      return NS_ERROR_CANNOT_CONVERT_DATA;
     }
 
-    if (checkedResult.value() < *aResult) {
-      *aResult = checkedResult.value();
+    if (checkedResult.value() < tentativeResult) {
+      tentativeResult = checkedResult.value();
     }
   }
 #  endif
 
+#  ifdef DEBUG_DISK_SPACE
+  printf("DiskInfo: %lu bytes\n", tentativeResult);
+#  endif
+
+  *aResult = tentativeResult;
+
   return NS_OK;
 
 #else
diff --git a/xpcom/io/nsLocalFileWin.cpp b/xpcom/io/nsLocalFileWin.cpp
index 4022af8dc1d0..37278f264d6f 100644
--- a/xpcom/io/nsLocalFileWin.cpp
+++ b/xpcom/io/nsLocalFileWin.cpp
@@ -2734,8 +2734,6 @@ nsLocalFile::GetDiskCapacity(int64_t* aDiskCapacity) {
     return NS_ERROR_INVALID_ARG;
   }
 
-  *aDiskCapacity = 0;
-
   nsresult rv = ResolveAndStat();
   if (NS_FAILED(rv)) {
     return rv;