Bug 239758 – Fix variable liveness for try catch in DFG

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

Created attachment 458335 [details]
the minimal poc

The following PoC outputs differently before/after JIT compilation.


function opt() {
	var b = false;
	var c = -b;
	try {
		throw "";
	} catch(e) {
	}
	return c;
}

let before = opt();
print(1/before); //-Infinity

for(var i=0;i<10000;i++){
	opt();
}

let afterJIT = opt();
print(1/afterJIT); //Infinity

[Radar WebKit Bug Importer]

<rdar://problem/92654142>

[Yusuke Suzuki]

Ah, this is caused by 230823.
Backward propagation is running before catch live variable preservation.

[Yusuke Suzuki]

Probably, we should insert catch-live-variable-insertion before backwards propagation.

[Yijia Huang]

Pull request: https://github.com/WebKit/WebKit/pull/9496

[Yijia Huang]

*** Bug 251411 has been marked as a duplicate of this bug. ***

[EWS]

Committed 259839@main (5e1033a7cd03): <https://commits.webkit.org/259839@main>

Reviewed commits have been landed. Closing PR #9496 and removing active labels.

According to acknowledgement, there seems a mistake here?

WebKit Bugzilla: 239758
CVE-2023-35074: Abysslab Dong Jun Kim(@smlijun) and Jong Seong Kim(@nevul37)

[Michael Catanzaro]

Hm, I wonder if they're supposed to be credited on some *other* CVE instead.

We can ask for this to be fixed. Who should this one be attributed to? "zhunkibatu"?

"zhunki", please.

Did you confirm who to aknowledge?

[Michael Catanzaro]

Looks like I missed this. I'll notify Apple Product Security after the holidays.

[Michael Catanzaro]

(In reply to Michael Catanzaro from comment #11)
> Looks like I missed this. I'll notify Apple Product Security after the
> holidays.

Actually I contacted Apple Product Security on October 1, but haven't received a response yet. The ticket number is OE092404867716.

They did respond to a similar request in another CVE, so my guess is they've lost track of this one.