Index: ELF/Writer.cpp
===================================================================
--- ELF/Writer.cpp
+++ ELF/Writer.cpp
@@ -1873,6 +1873,12 @@
   FileSize = alignTo(Off, Config->Wordsize);
 }
 
+static std::string rangeToString(uint64_t Addr, uint64_t Len) {
+  if (Len == 0)
+    return "<empty range at 0x" + utohexstr(Addr) + ">";
+  return "[0x" + utohexstr(Addr) + ", 0x" + utohexstr(Addr + Len - 1) + "]";
+}
+
 // Assign file offsets to output sections.
 template <class ELFT> void Writer<ELFT>::assignFileOffsets() {
   uint64_t Off = 0;
@@ -1897,6 +1903,25 @@
 
   SectionHeaderOff = alignTo(Off, Config->Wordsize);
   FileSize = SectionHeaderOff + (OutputSections.size() + 1) * sizeof(Elf_Shdr);
+
+  // Our logic assumes that sections have rising VA within the same segment.
+  // With use of linker scripts it is possible to violate this rule and get file
+  // offset overlaps or overflows. That should never happen with a valid script
+  // which does not move the location counter backwards and usually scripts do
+  // not do that. Unfortunately, there are apps in the wild, for example, Linux
+  // kernel, which control segment distribution explicitly and move the counter
+  // backwards, so we have to allow doing that to support linking them. We
+  // perform non-critical checks for overlaps in checkNoOverlappingSections(),
+  // but here we want to prevent file size overflows because it would crash the
+  // linker.
+  for (OutputSection *Sec : OutputSections) {
+    if (Sec->Type == SHT_NOBITS)
+      continue;
+    if ((Sec->Offset > FileSize) || (Sec->Offset + Sec->Size > FileSize))
+      error("unable to place section " + Sec->Name + " at file offset " +
+            rangeToString(Sec->Offset, Sec->Offset + Sec->Size) +
+            "; check your linker script for overflows");
+  }
 }
 
 // Finalize the program headers. We call this function after we assign
@@ -1935,12 +1960,6 @@
   }
 }
 
-static std::string rangeToString(uint64_t Addr, uint64_t Len) {
-  if (Len == 0)
-    return "<empty range at 0x" + utohexstr(Addr) + ">";
-  return "[0x" + utohexstr(Addr) + ", 0x" + utohexstr(Addr + Len - 1) + "]";
-}
-
 // Check whether sections overlap for a specific address range (file offsets,
 // load and virtual adresses).
 //
Index: test/ELF/linkerscript/Inputs/sections-va-overflow.s
===================================================================
--- test/ELF/linkerscript/Inputs/sections-va-overflow.s
+++ test/ELF/linkerscript/Inputs/sections-va-overflow.s
@@ -0,0 +1,6 @@
+.global _start
+_start:
+  retq
+
+.bss
+.space 0x2000
Index: test/ELF/linkerscript/sections-va-overflow.test
===================================================================
--- test/ELF/linkerscript/sections-va-overflow.test
+++ test/ELF/linkerscript/sections-va-overflow.test
@@ -0,0 +1,22 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/sections-va-overflow.s -o %t.o
+# RUN: not ld.lld -o /dev/null --script %s %t.o 2>&1 | FileCheck %s -check-prefix=ERR
+
+PHDRS {
+  ph_headers PT_PHDR PHDRS;
+  ph_text PT_LOAD FILEHDR PHDRS FLAGS (0x1 | 0x4);
+}
+
+SECTIONS { 
+ . = 0xffffffff20000000;
+ .text : { *(.text*) } : ph_text
+ .test 0x1000 : { BYTE(0) }
+ .bss : { *(.bss*) }
+}
+
+## Section .test has VA 0x1000 and placed in the same segment as section .text
+## with VA 0xffffffff20000000. That might be technically correct, but most probably
+## is a result of a broken script file and causes file offset calculation overflow.
+## It seems we do not have to support it, so we don't and we report an error in this case.
+# ERR: error: unable to place section .text at file offset [0xFFFFFFFF20000000, 0xFFFFFFFE40000000]; check your linker script for overflows
+# ERR-NOT: unable to place section .bss