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Comment by matthberg | Hacker News Reader

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matthberg

The tweet announcing it: https://twitter.com/pwnsdx/status/1040944750973595649

The code that causes the crash (safe to open): https://gist.github.com/pwnsdx/ce64de2760996a6c432f06d612e33...

The demo itself (causes crash): https://cdn.rawgit.com/pwnsdx/ce64de2760996a6c432f06d612e33a...

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Haha! Looks like another modern version of zip-bomb[0] or should I say - div-bomb:)

[0] https://en.wikipedia.org/wiki/Zip_bomb

Interesting, it's simply a few thousand nested divs with a huge blur on them. Is it something specific about blur? Or could you do the same thing with box-shadows, etc, if there are enough of them?

-webkit-backdrop-filter forces layerization (i.e. it promotes whatever box it's in to a Core Animation layer), while box shadows don't. This resource exhaustion bug is specific to CA layers, so you wouldn't see this with box shadows.

Works on iPhone SE w/ iOS 12 latest public beta.

Worked on iOS 11.4 iPhone 8

It works!

More details from the Twitter thread: it's iOS 7 and up, and it also works on watchOS 5. In some apps like chrome or opera it isn't a full crash, just a "springboard crash".

I always said iOS 7 was a disaster. iOS 6- opened 8 tabs at most (deleting old tabs) and no one complained. These new youngster oses can not even manage memory in a right way — now with all these GCs no one knows how to do it.

DO NOT CLICK THE LINK! Hour later I am still unable to restart my phone. It hangs on logo!! This may be a permanent fuck ;( unsure exact version but I have iOS 7 that hasnt been updated in about six months.

try a force restart (home + power button for about 10 seconds)

What is home?

I think he meant hold down volume down + power button for 10 seconds.

Older iPhones with physical home button use that for restart.

Last year’s model.

Last year’s iPhones 8 use volume down + power for restart because home is not a button, but a sensor and it has to be powered to work.

there's no iOS 7 device without home button :)

It's the name of the round button at the bottom of the iPhones without Face ID.

Seems like on restart Safari wants to revisit previously opened pages and crashes again ad infinitum. Isn't there a way to cold-restart iOS devices or some such (like the magic "Zap NVRAM and repair permissions" procedure back in PowerMac times)?

"Seems like on restart Safari wants to revisit previously opened pages"

I've always found that behavior annoying. If I want to revisit the last page, I can find it in history.

I'm sure you're in the absolute minority. Most people want all apps, including the browser, to stay the way they were when they closed them, even after a reboot

Do you have data for this? I'm also in the absolute minority

Me too. I want a blank page when I open my browser. If I reboot a device, I want nothing but base system running when it restarts.

I sure as heck want my tabs back. But I'd settle for "restore tabs" as I have to do that a lot in chrome on my MacBook Pro. On my Android, the tabs are just there and I really appreciate it. I have over a dozen tabs open on my phone and two dozen on my laptop.

It’s very convenient, but isn’t that scenario better covered by hibernating the os? That covers all app and doesn’t require any app to have special behaviour coded in

If I never had to restart, sure. I have to restart my laptop weekly at least. Heck, it locked up twice last week opening Diablo 3 forcing a hard power cycle. My phone gets restarted less often but still gets into odd states where a reboot is needed.

tangential, but check out that your power supply is ok, that's the second most common source of random lockups during load (I assume drivers are up to date, that'd be the first)

But that’s why you need a “safe start mode” where you can start the app with a clean slate. Several Microsoft Office apps do this now. Given iOS’s repeated “crash loop” issues you’d think they’d have learnt by now.

That always bothers me. What if a page was (dumbly) in a state that makes a change I don't want?

I'm in that minority too, I guess. There's nothing more grating than to explicitly close all tabs, only to be asked whether you want to open them again. For me, tabs are like this useless plaque that slowly accumulates and needs to be blown away every two or three days.

Yep. I know someone who keeps dozens and dozens of tabs open on an iPhone. It's kind of like a bookmark library.

I explained that there is a bookmark feature just for this sort of thing, but when you're used to doing something one way, change can be slow.

Able to reboot fine on iOS 12 after the crash. Safari didn’t try to reopen closed windows as well.

No hang on 11.4.1. It came back fine.

DO NOT CLICK THE LINK!

Never imagined I'd read those words at HN. How times have changed. Be sensible people.

If you use iCloud for Safari, you can close another device's Safari tab from your Mac. click the iCloud tabs icon on desktop Safari, then click the circle-x to close the offending tab.

This is a great suggestion for those stuck on this crash

works on iOS 12 GM also

I wonder if they are trying to fix it before tomorrow’s release.

It is more likely that they would fix this in a 12.0.1 that will be available shortly than to change the 12 release as all new iPhones come preloaded with 12.

For me it just closes the Hacker News app. No reboot.

The Hacker News app??

I think he means the web browser app. Probably only used for Hacker News. Like a boss.

I assume that he means one of the many Hacker News clients available for iOS such as MiniHack [1] or Simple Reader for Hacker News [2].

[1] https://itunes.apple.com/it/app/minihack-hacker-news-client/...

[2] https://itunes.apple.com/us/app/simple-reader-for-hacker-new...

Survivorship bias

I clicked the third link thinking it was a link to a demo video. I can confirm that 1) it’s not a link to a demo video 2) it rebooted my iPad.

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