TUCoPS :: Unix :: General :: unix5093.htm

COMMAND
	Ada compiler /tmp race condition
SYSTEMS AFFECTED
	 GNAT 3.12p
	 GNAT 3.13p
	 GNAT 3.14p
	
PROBLEM
	In Florian Weimer [http://CERT.Uni-Stuttgart.DE/people/fw/] CERT
	advisory [2002-02:01] :
	
	The Ada language offers a facility to create named temporary files (see
	ISO/IEC 8652:1995, section A.8.5.2). The GNAT run-time library creates
	these temporary files in an unsafe way, which can result in exploitable
	/tmp race conditions.
	
	In addition, the procedure GNAT.OS_Lib.Create_Temp_File creates the
	temporary file in the current directory and does not retry with a
	different file name if the generated random file name has come into
	existance before the file is opened using O_EXCL.
SOLUTION
	The patch below replaces the calls to tmpnam() or mktemp() with ones to
	mkstemp(). Of course, this only works on systems where mkstemp() is
	available.
	
	Patch for GNAT 3.14p:
	
	 http://cert.uni-stuttgart.de/files/fw/gnat-3.14p-mkstemp.diff