[Lldb-commits] [PATCH] D75925: [lldb] reject `.debug_arange` sections with nonzero segment size

[Luke Drummond via Phabricator via lldb-commits]

ldrumm created this revision.
ldrumm added reviewers: clayborg, jasonmolenda.
ldrumm added a project: LLDB.

  If a producer emits a nonzero segment size, `lldb` will silently read
  incorrect values and crash, or do something worse later, as the tuple
  size is expected to be 2, rather than 3.
  
  Neither LLVM, nor GCC produce segmented aranges, but this dangerous case
  should still be checked and handled.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D75925

Files:
  lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugArangeSet.cpp


Index: lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugArangeSet.cpp
===================================================================
--- lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugArangeSet.cpp
+++ lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugArangeSet.cpp
@@ -63,7 +63,8 @@
   // 1 - the version looks good
   // 2 - the address byte size looks plausible
   // 3 - the length seems to make sense
-  // size looks plausible
+  // 4 - size looks plausible
+  // 5 - the arange tuples do not contain a segment field
   if (m_header.version < 2 || m_header.version > 5)
     return llvm::make_error<llvm::object::GenericBinaryError>(
         "Invalid arange header version");
@@ -81,6 +82,10 @@
     return llvm::make_error<llvm::object::GenericBinaryError>(
         "Invalid arange header length");
 
+  if (m_header.seg_size)
+    return llvm::make_error<llvm::object::GenericBinaryError>(
+        "segmented arange entries are not supported");
+
   // The first tuple following the header in each set begins at an offset
   // that is a multiple of the size of a single tuple (that is, twice the
   // size of an address). The header is padded, if necessary, to the


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D75925.249386.patch
Type: text/x-patch
Size: 1178 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/lldb-commits/attachments/20200310/856b63c9/attachment.bin>