1323092 - Crash in libFontParser.dylib@0x8c5b

Status: RESOLVED WONTFIX

(Core :: Graphics: Text, defect, P3)

Description

[Nicholas Nethercote [inactive]]

This bug was filed from the Socorro interface and is 
report bp-0c26dbee-ccc2-4c6f-8f3e-e9a552161210.
=============================================================

This Mac crash first showed up in August and has been moderate volume since. It's the #23 topcrash on Mac in the past 7 days. There is quite some variation in the stacks. The following list shows the Mozilla functions that called into the system font libs, in order of frequency:

> SkScalerContext_Mac::generateMetrics(SkGlyph*)
> 
> _cairo_quartz_scaled_glyph_init
> 
> gfxMacFont::InitMetrics()
> 
> MacFontInfo::LoadFontFamilyData(nsAString_internal const&)
> 
> gfxCoreTextShaper::ShapeText(mozilla::gfx::DrawTarget*, char16_t const*, unsigned int, unsigned int, mozilla::unicode::Script, bool, gfxShapedText*)

jfkthame: any ideas?

Comment 1

[Jonathan Kew [:jfkthame]]

This looks like an Apple bug to me. It's crashing deep inside the macOS font code, presumably due to some kind of anomaly in a font, and I think this must be a locally-installed font (rather than a @font-face resource that should have been sanitized) because of gfxCoreTextShaper::ShapeText in the stack. We only use gfxCoreTextShaper for fonts with AAT tables, and OTS strips AAT tables from downloadable fonts so it must be a local font.

It might be caused by a flaw in a font actually shipped with macOS -- wouldn't be the first time that has happened -- or it might be a third-party font that some users have installed (there aren't a huge number of third-party AAT fonts around, but they do exist). Really difficult to tell unless we can reproduce or somehow pinpoint the specific font that is triggering the crash.

Comment 2

[Sylvestre Ledru [:Sylvestre]]

Closing because no crash reported since 12 weeks.