Yes, I saw the IEP feature on the z14 announcement. There were severe restrictions on LOC=64 code before (mainly, must be non-interruptible) so since they added EXECUTABLE= to the LOC=64 allocation logic, I figured they might have eased up on what kind of code was allowed above the bar.
So... Is the target of an EXECUTE considered to be an executable instruction if it's in EXECUTABLE=NO storage? Robert Ngan CeleritiFinTech Services -----Original Message----- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of Charles Mills Sent: Friday, July 28, 2017 12:07 To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: LOC=64 executable code? In other words, EXECUTABLE=YES is not some new RMODE=64 feature. EXECUTABLE=NO is a new security feature. It is a guard against buffer overflow type vulnerabilities in which a bad guy sends you some message (like a Web URL) that is actually machine instructions and also manages to overlay code thus causing a branch to the instructions in the message. You can now mark storage non-executable, and the hardware will not allow a branch to it. ALL storage today is EXECUTABLE=YES. EXECUTABLE=YES is not new; EXECUTABLE=NO is new. Charles -----Original Message----- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of Tom Russell Sent: Friday, July 28, 2017 9:43 AM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: LOC=64 executable code? >Date: Fri, 28 Jul 2017 00:14:46 +0000 >From: "Ngan, Robert" <rn...@dxc.com> >Subject: LOC=64 executable code? >Just noticed that the z/OS 2.3 manuals mention EXECUTABLE=YES|NO parameter for >IARV64 GETSTOR requests. >Anyone have a summary of what kinds of code we can move above the bar in z/OS >2.3? >Robert Ngan >CeleritiFinTech Services z14 and z/OS 2.3 support a new facility called Instruction Execution Protection (IEP) based on DAT table entry bit •RSM provides new function to request that non-executable memory be allocated •Exploitation support new EXECUTABLE=NO option on IARV64 and STORAGE •Any attempt to execute an instruction within such an area will result in a program check •Could be an indication of an attempt to violate system integrity •RTM will write LOGREC record of any program-check that results from IEP •Support will also be available for z/OS 2.2 and later running on z14 G. Tom Russell “Stay calm. Be brave. Wait for the signs” — Jasper FriendlyBear “… and remember to leave good news alone.” — Gracie HeavyHand DXC Technology Company - Headquarters: 1775 Tysons Boulevard, Tysons, Virginia 22102, USA. DXC Technology Company -- This message is transmitted to you by or on behalf of DXC Technology Company or one of its affiliates. It is intended exclusively for the addressee. The substance of this message, along with any attachments, may contain proprietary, confidential or privileged information or information that is otherwise legally exempt from disclosure. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient of this message, you are not authorized to read, print, retain, copy or disseminate any part of this message. If you have received this message in error, please destroy and delete all copies and notify the sender by return e-mail. Regardless of content, this e-mail shall not operate to bind DXC Technology Company or any of its affiliates to any order or other contract unless pursuant to explicit written agreement or government initiative expressly permitting the use of e-mail for such purpose.
