20318882 problem in UTILITY/P7ZIP s11u2-sru
authorDanek Duvall <danek.duvall@oracle.com>
Fri, 26 Jun 2015 13:51:45 -0700
branchs11u2-sru
changeset 4595 84742988fa3b
parent 4572 69ee2519dedf
child 4596 642f95a97bb3
20318882 problem in UTILITY/P7ZIP
components/p7zip/patches/CVE-2015-1038.patch
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/components/p7zip/patches/CVE-2015-1038.patch	Fri Jun 26 13:51:45 2015 -0700
@@ -0,0 +1,326 @@
+This patch fixes CVE-2015-1038, filed upstream as
+
+    http://sourceforge.net/p/p7zip/bugs/147/
+
+The patch contents come from
+
+    http://sourceforge.net/p/p7zip/bugs/_discuss/thread/17901103/2f9c/attachment/CVE-2015-1038.patch
+
+This will presumably be fixed upstream at some point after 9.38.1.
+
+======================================================================
+
+Author: Ben Hutchings <[email protected]>
+Date: Tue, 19 May 2015 02:38:40 +0100
+Description: Delay creation of symlinks to prevent arbitrary file writes (CVE-2015-1038)
+Bug-Debian: https://bugs.debian.org/774660
+
+Alexander Cherepanov discovered that 7zip is susceptible to a
+directory traversal vulnerability.  While extracting an archive, it
+will extract symlinks and then follow them if they are referenced in
+further entries.  This can be exploited by a rogue archive to write
+files outside the current directory.
+
+We have to create placeholder files (which we already do) and delay
+creating symlinks until the end of extraction.
+
+Due to the possibility of anti-items (deletions) in the archive, it is
+possible for placeholders to be deleted and replaced before we create
+the symlinks.  It's not clear that this can be used for mischief, but
+GNU tar guards against similar problems by checking that the placeholder
+still exists and is the same inode.  XXX It also checks 'birth time' but
+this isn't portable.  We can probably get away with comparing ctime
+since we don't support hard links.
+
+--- a/CPP/7zip/UI/Agent/Agent.cpp
++++ b/CPP/7zip/UI/Agent/Agent.cpp
[email protected]@ -424,6 +424,8 @@ STDMETHODIMP CAgentFolder::Extract(const
+   CMyComPtr<IArchiveExtractCallback> extractCallback = extractCallbackSpec;
+   UStringVector pathParts;
+   CProxyFolder *currentProxyFolder = _proxyFolderItem;
++  HRESULT res;
++
+   while (currentProxyFolder->Parent)
+   {
+     pathParts.Insert(0, currentProxyFolder->Name);
[email protected]@ -445,8 +447,11 @@ STDMETHODIMP CAgentFolder::Extract(const
+       (UInt64)(Int64)-1);
+   CUIntVector realIndices;
+   GetRealIndices(indices, numItems, realIndices);
+-  return _agentSpec->GetArchive()->Extract(&realIndices.Front(),
++  res = _agentSpec->GetArchive()->Extract(&realIndices.Front(),
+       realIndices.Size(), testMode, extractCallback);
++  if (res == S_OK && !extractCallbackSpec->CreateSymLinks())
++    res = E_FAIL;
++  return res;
+   COM_TRY_END
+ }
+ 
+--- a/CPP/7zip/UI/Agent/ArchiveFolder.cpp
++++ b/CPP/7zip/UI/Agent/ArchiveFolder.cpp
[email protected]@ -20,6 +20,8 @@ STDMETHODIMP CAgentFolder::CopyTo(const
+   CMyComPtr<IArchiveExtractCallback> extractCallback = extractCallbackSpec;
+   UStringVector pathParts;
+   CProxyFolder *currentProxyFolder = _proxyFolderItem;
++  HRESULT res;
++
+   while (currentProxyFolder->Parent)
+   {
+     pathParts.Insert(0, currentProxyFolder->Name);
[email protected]@ -46,8 +48,11 @@ STDMETHODIMP CAgentFolder::CopyTo(const
+       (UInt64)(Int64)-1);
+   CUIntVector realIndices;
+   GetRealIndices(indices, numItems, realIndices);
+-  return _agentSpec->GetArchive()->Extract(&realIndices.Front(),
++  res = _agentSpec->GetArchive()->Extract(&realIndices.Front(),
+       realIndices.Size(), BoolToInt(false), extractCallback);
++  if (res == S_OK && !extractCallbackSpec->CreateSymLinks())
++    res = E_FAIL;
++  return res;
+   COM_TRY_END
+ }
+ 
+--- a/CPP/7zip/UI/Client7z/Client7z.cpp
++++ b/CPP/7zip/UI/Client7z/Client7z.cpp
[email protected]@ -197,8 +197,11 @@ private:
+   COutFileStream *_outFileStreamSpec;
+   CMyComPtr<ISequentialOutStream> _outFileStream;
+ 
++  CObjectVector<NWindows::NFile::NDirectory::CDelayedSymLink> _delayedSymLinks;
++
+ public:
+   void Init(IInArchive *archiveHandler, const UString &directoryPath);
++  bool CreateSymLinks();
+ 
+   UInt64 NumErrors;
+   bool PasswordIsDefined;
[email protected]@ -392,11 +395,22 @@ STDMETHODIMP CArchiveExtractCallback::Se
+   }
+   _outFileStream.Release();
+   if (_extractMode && _processedFileInfo.AttribDefined)
+-    NFile::NDirectory::MySetFileAttributes(_diskFilePath, _processedFileInfo.Attrib);
++    NFile::NDirectory::MySetFileAttributes(_diskFilePath, _processedFileInfo.Attrib, &_delayedSymLinks);
+   PrintNewLine();
+   return S_OK;
+ }
+ 
++bool CArchiveExtractCallback::CreateSymLinks()
++{
++  bool success = true;
++
++  for (int i = 0; i != _delayedSymLinks.Size(); ++i)
++    success &= _delayedSymLinks[i].Create();
++
++  _delayedSymLinks.Clear();
++
++  return success;
++}
+ 
+ STDMETHODIMP CArchiveExtractCallback::CryptoGetTextPassword(BSTR *password)
+ {
+--- a/CPP/7zip/UI/Common/ArchiveExtractCallback.cpp
++++ b/CPP/7zip/UI/Common/ArchiveExtractCallback.cpp
[email protected]@ -453,12 +453,24 @@ STDMETHODIMP CArchiveExtractCallback::Se
+     NumFiles++;
+ 
+   if (_extractMode && _fi.AttribDefined)
+-    NFile::NDirectory::MySetFileAttributes(_diskFilePath, _fi.Attrib);
++    NFile::NDirectory::MySetFileAttributes(_diskFilePath, _fi.Attrib, &_delayedSymLinks);
+   RINOK(_extractCallback2->SetOperationResult(operationResult, _encrypted));
+   return S_OK;
+   COM_TRY_END
+ }
+ 
++bool CArchiveExtractCallback::CreateSymLinks()
++{
++  bool success = true;
++
++  for (int i = 0; i != _delayedSymLinks.Size(); ++i)
++    success &= _delayedSymLinks[i].Create();
++
++  _delayedSymLinks.Clear();
++
++  return success;
++}
++
+ /*
+ STDMETHODIMP CArchiveExtractCallback::GetInStream(
+     const wchar_t *name, ISequentialInStream **inStream)
+--- a/CPP/7zip/UI/Common/ArchiveExtractCallback.h
++++ b/CPP/7zip/UI/Common/ArchiveExtractCallback.h
[email protected]@ -6,6 +6,8 @@
+ #include "Common/MyCom.h"
+ #include "Common/Wildcard.h"
+ 
++#include "Windows/FileDir.h"
++
+ #include "../../IPassword.h"
+ 
+ #include "../../Common/FileStreams.h"
[email protected]@ -83,6 +85,8 @@ class CArchiveExtractCallback:
+   UInt64 _packTotal;
+   UInt64 _unpTotal;
+ 
++  CObjectVector<NWindows::NFile::NDirectory::CDelayedSymLink> _delayedSymLinks;
++
+   void CreateComplexDirectory(const UStringVector &dirPathParts, UString &fullPath);
+   HRESULT GetTime(int index, PROPID propID, FILETIME &filetime, bool &filetimeIsDefined);
+   HRESULT GetUnpackSize();
[email protected]@ -138,6 +142,7 @@ public:
+       const UStringVector &removePathParts,
+       UInt64 packSize);
+ 
++  bool CreateSymLinks();
+ };
+ 
+ #endif
+--- a/CPP/7zip/UI/Common/Extract.cpp
++++ b/CPP/7zip/UI/Common/Extract.cpp
[email protected]@ -96,6 +96,9 @@ static HRESULT DecompressArchive(
+   else
+     result = archive->Extract(&realIndices.Front(), realIndices.Size(), testMode, extractCallbackSpec);
+ 
++  if (result == S_OK && !extractCallbackSpec->CreateSymLinks())
++    result = E_FAIL;
++
+   return callback->ExtractResult(result);
+ }
+ 
+--- a/CPP/Windows/FileDir.cpp
++++ b/CPP/Windows/FileDir.cpp
[email protected]@ -453,9 +453,10 @@ bool SetDirTime(LPCWSTR fileName, const
+ }
+ 
+ #ifndef _UNICODE
+-bool MySetFileAttributes(LPCWSTR fileName, DWORD fileAttributes)
++bool MySetFileAttributes(LPCWSTR fileName, DWORD fileAttributes,
++			 CObjectVector<CDelayedSymLink> *delayedSymLinks)
+ {  
+-  return MySetFileAttributes(UnicodeStringToMultiByte(fileName, CP_ACP), fileAttributes);
++  return MySetFileAttributes(UnicodeStringToMultiByte(fileName, CP_ACP), fileAttributes, delayedSymLinks);
+ }
+ 
+ bool MyRemoveDirectory(LPCWSTR pathName)
[email protected]@ -488,7 +489,8 @@ static int convert_to_symlink(const char
+   return -1;
+ }
+ 
+-bool MySetFileAttributes(LPCTSTR fileName, DWORD fileAttributes)
++bool MySetFileAttributes(LPCTSTR fileName, DWORD fileAttributes,
++			 CObjectVector<CDelayedSymLink> *delayedSymLinks)
+ {
+   if (!fileName) {
+     SetLastError(ERROR_PATH_NOT_FOUND);
[email protected]@ -520,7 +522,9 @@ bool MySetFileAttributes(LPCTSTR fileNam
+      stat_info.st_mode = fileAttributes >> 16;
+ #ifdef ENV_HAVE_LSTAT
+      if (S_ISLNK(stat_info.st_mode)) {
+-        if ( convert_to_symlink(name) != 0) {
++        if (delayedSymLinks)
++          delayedSymLinks->Add(CDelayedSymLink(name));
++        else if ( convert_to_symlink(name) != 0) {
+           TRACEN((printf("MySetFileAttributes(%s,%d) : false-3\n",name,fileAttributes)))
+           return false;
+         }
[email protected]@ -924,4 +928,41 @@ bool CTempDirectory::Create(LPCTSTR pref
+ }
+ 
+ 
++#ifdef ENV_UNIX
++
++CDelayedSymLink::CDelayedSymLink(LPCSTR source)
++  : _source(source)
++{
++  struct stat st;
++
++  if (lstat(_source, &st) == 0) {
++    _dev = st.st_dev;
++    _ino = st.st_ino;
++  } else {
++    _dev = 0;
++  }
++}
++
++bool CDelayedSymLink::Create()
++{
++  struct stat st;
++
++  if (_dev == 0) {
++    errno = EPERM;
++    return false;
++  }
++  if (lstat(_source, &st) != 0)
++    return false;
++  if (_dev != st.st_dev || _ino != st.st_ino) {
++    // Placeholder file has been overwritten or moved by another
++    // symbolic link creation
++    errno = EPERM;
++    return false;
++  }
++
++  return convert_to_symlink(_source) == 0;
++}
++
++#endif // ENV_UNIX
++
+ }}}
+--- a/CPP/Windows/FileDir.h
++++ b/CPP/Windows/FileDir.h
[email protected]@ -4,6 +4,7 @@
+ #define __WINDOWS_FILEDIR_H
+ 
+ #include "../Common/MyString.h"
++#include "../Common/MyVector.h"
+ #include "Defs.h"
+ 
+ /* GetFullPathName for 7zAES.cpp */
[email protected]@ -13,11 +14,15 @@ namespace NWindows {
+ namespace NFile {
+ namespace NDirectory {
+ 
++class CDelayedSymLink;
++
+ bool SetDirTime(LPCWSTR fileName, const FILETIME *creationTime, const FILETIME *lastAccessTime, const FILETIME *lastWriteTime);
+ 
+-bool MySetFileAttributes(LPCTSTR fileName, DWORD fileAttributes);
++bool MySetFileAttributes(LPCTSTR fileName, DWORD fileAttributes,
++			 CObjectVector<CDelayedSymLink> *delayedSymLinks = 0);
+ #ifndef _UNICODE
+-bool MySetFileAttributes(LPCWSTR fileName, DWORD fileAttributes);
++bool MySetFileAttributes(LPCWSTR fileName, DWORD fileAttributes,
++			 CObjectVector<CDelayedSymLink> *delayedSymLinks = 0);
+ #endif
+ 
+ bool MyMoveFile(LPCTSTR existFileName, LPCTSTR newFileName);
[email protected]@ -80,6 +85,31 @@ public:
+   bool Remove();
+ };
+ 
++// Symbolic links must be created last so that they can't be used to
++// create or overwrite files above the extraction directory.
++class CDelayedSymLink
++{
++#ifdef ENV_UNIX
++  // Where the symlink should be created.  The target is specified in
++  // the placeholder file.
++  AString _source;
++
++  // Device and inode of the placeholder file.  Before creating the
++  // symlink, we must check that these haven't been changed by creation
++  // of another symlink.
++  dev_t _dev;
++  ino_t _ino;
++
++public:
++  explicit CDelayedSymLink(LPCSTR source);
++  bool Create();
++#else // !ENV_UNIX
++public:
++  CDelayedSymLink(LPCSTR source) {}
++  bool Create() { return true; }
++#endif // ENV_UNIX
++};
++
+ #ifdef _UNICODE
+ typedef CTempFile CTempFileW;
+ #endif