Apply patch to avoid truncating of arbitrary files. Thanks to Bryan

[apt.git] / apt-pkg / contrib / fileutl.cc

diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
index 2b7e25080ef52578fbf672331a0e549ec5476073..a5976cf3af811fb3abe6b3d0c966a6b2b6779b02 100644 (file)
--- a/apt-pkg/contrib/fileutl.cc
+++ b/apt-pkg/contrib/fileutl.cc
@@ -138,7 +138,9 @@ bool CopyFile(FileFd &From,FileFd &To)
    close at some time. */
 int GetLock(string File,bool Errors)
 {
-   int FD = open(File.c_str(),O_RDWR | O_CREAT | O_TRUNC,0640);
+   // GetLock() is used in aptitude on directories with public-write access
+   // Use O_NOFOLLOW here to prevent symlink traversal attacks
+   int FD = open(File.c_str(),O_RDWR | O_CREAT | O_NOFOLLOW,0640);
    if (FD < 0)
    {
       // Read only .. cant have locking problems there.