[lld] r315036 - [ELF] Don't crash when parsing a file with out-of-bounds version references

[Alexander Richardson via llvm-commits]

Author: arichardson
Date: Thu Oct  5 16:28:34 2017
New Revision: 315036

URL: http://llvm.org/viewvc/llvm-project?rev=315036&view=rev
Log:
[ELF] Don't crash when parsing a file with out-of-bounds version references

Summary:
We were crashing when linking telnetd in FreeBSD because lld was emitting
corrupted output files for --norosegment. In this file the version index of some symbols
was set to 9 but lld only found 8 version definitions.

I am not sure how to create a minimal .so file that also exposes this behaviour so I just added the one that initially caused the error to Inputs/

This partially addresses https://bugs.llvm.org/show_bug.cgi?id=34705

Reviewers: ruiu, rafael, pcc, grimar

Reviewed By: ruiu

Subscribers: emaste, krytarowski

Tags: #lld

Differential Revision: https://reviews.llvm.org/D38397

Modified:
    lld/trunk/ELF/InputFiles.cpp
    lld/trunk/test/ELF/corrupted-version-reference.s

Modified: lld/trunk/ELF/InputFiles.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/InputFiles.cpp?rev=315036&r1=315035&r2=315036&view=diff
==============================================================================
--- lld/trunk/ELF/InputFiles.cpp (original)
+++ lld/trunk/ELF/InputFiles.cpp Thu Oct  5 16:28:34 2017
@@ -780,9 +780,7 @@ template <class ELFT> void SharedFile<EL
       if (VersymIndex >= Verdefs.size()) {
         error("corrupt input file: version definition index " +
               Twine(VersymIndex) + " for symbol " + Name +
-              " is greater than the maximum value " +
-              Twine(Verdefs.size() - 1) + "\n>>> symbol is defined in " +
-              toString(this));
+              " is out of bounds\n>>> defined in " + toString(this));
         continue;
       }
       V = Verdefs[VersymIndex];

Modified: lld/trunk/test/ELF/corrupted-version-reference.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/corrupted-version-reference.s?rev=315036&r1=315035&r2=315036&view=diff
==============================================================================
--- lld/trunk/test/ELF/corrupted-version-reference.s (original)
+++ lld/trunk/test/ELF/corrupted-version-reference.s Thu Oct  5 16:28:34 2017
@@ -1,8 +1,8 @@
 # RUN: llvm-mc -triple=mips64-unknown-freebsd %s -filetype=obj -o %t.o
 # RUN: not ld.lld %t.o %S/Inputs/corrupt-version-reference.so -o %t.exe 2>&1 | FileCheck %s
 
-# CHECK: error: corrupt input file: version definition index 9 for symbol __cxa_finalize is greater than the maximum value 8
-# CHECK: >>> symbol is defined in {{.+}}/corrupt-version-reference.so
+# CHECK: error: corrupt input file: version definition index 9 for symbol __cxa_finalize is out of bounds
+# CHECK: >>> defined in {{.+}}/corrupt-version-reference.so
 
 .globl __start
 __start: