[PATCH] D138986: [AIX][BigArchive] Treat the archive is empty if the first child member offset is zero

[Kai Luo via Phabricator via llvm-commits]

lkail updated this revision to Diff 484731.
lkail added a comment.
Herald added a subscriber: hiraditya.

Check if the offset of the first member is still in the buffer. Fixed asan errors.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D138986/new/

https://reviews.llvm.org/D138986

Files:
  llvm/include/llvm/Object/Archive.h
  llvm/lib/Object/Archive.cpp
  llvm/test/Object/archive-big-malformed-first-member.test
  llvm/test/Object/archive-big-read-empty-with-freelist.test


Index: llvm/test/Object/archive-big-read-empty-with-freelist.test
===================================================================
--- llvm/test/Object/archive-big-read-empty-with-freelist.test
+++ llvm/test/Object/archive-big-read-empty-with-freelist.test
@@ -1,3 +1,3 @@
 # Test reading an empty archive with free list in it.
-# RUN: not llvm-ar tv %p/Inputs/aix-empty-big-archive-with-freelist.a 2>&1 \
-# RUN:   | grep 'truncated or malformed archive'
+# RUN: llvm-ar tv %p/Inputs/aix-empty-big-archive-with-freelist.a 2>&1 \
+# RUN:   | not grep 'truncated or malformed archive'
Index: llvm/test/Object/archive-big-malformed-first-member.test
===================================================================
--- /dev/null
+++ llvm/test/Object/archive-big-malformed-first-member.test
@@ -0,0 +1,7 @@
+# Test reading an empty archive with first member's offset is not zero.
+# RUN: echo    "<bigaf>" > %t.a
+# RUN: echo -n "0                   0                   0                   128                 0                   0                   " >> %t.a
+# RUN: not llvm-ar tv %t.a 2>&1 | grep 'truncated or malformed archive'
+# RUN: echo    "<bigaf>" > %t.a
+# RUN: echo -n "0                   0                   0                   28                  0                   0                   " >> %t.a
+# RUN: not llvm-ar tv %t.a 2>&1 | grep 'truncated or malformed archive'
Index: llvm/lib/Object/Archive.cpp
===================================================================
--- llvm/lib/Object/Archive.cpp
+++ llvm/lib/Object/Archive.cpp
@@ -949,7 +949,15 @@
     return child_iterator::itr(
         Child(this, FirstRegularData, FirstRegularStartOfFile), Err);
 
-  const char *Loc = Data.getBufferStart() + getFirstChildOffset();
+  uint64_t FirstChildOffset = getFirstChildOffset();
+  const char *Loc = Data.getBufferStart() + FirstChildOffset;
+  if (Loc >= Data.getBufferEnd()) {
+    Err = malformedError("First member offset " + Twine(FirstChildOffset) +
+                         " is beyond the data buffer which has size of " +
+                         Twine(Data.getBufferSize()));
+    return child_end();
+  }
+
   Child C(this, Loc, &Err);
   if (Err)
     return child_end();
Index: llvm/include/llvm/Object/Archive.h
===================================================================
--- llvm/include/llvm/Object/Archive.h
+++ llvm/include/llvm/Object/Archive.h
@@ -410,9 +410,7 @@
   BigArchive(MemoryBufferRef Source, Error &Err);
   uint64_t getFirstChildOffset() const override { return FirstChildOffset; }
   uint64_t getLastChildOffset() const { return LastChildOffset; }
-  bool isEmpty() const override {
-    return Data.getBufferSize() == sizeof(FixLenHdr);
-  };
+  bool isEmpty() const override { return getFirstChildOffset() == 0; }
 };
 
 } // end namespace object


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D138986.484731.patch
Type: text/x-patch
Size: 2817 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20221222/407b9340/attachment.bin>