"Panic: misaligned pointer reference" in swash (rustc 1.70.0)

[ruifengx]

Is there an existing issue for this?

• I have searched the existing issues.

Is this issue related to iced?

• My hardware is compatible and my graphics drivers are up-to-date.

What happened?

Upgrade to rustc 1.70.0. I just confirmed that the crash cannot be reproduced in 1.69.0.

Use the master branch for advanced-text feature:

[dependencies.iced]
git = "https://github.com/iced-rs/iced.git"
rev = "fcb1b454368638209862aeb5db41bc5f7d6d51a7"

Build and run the following simple program:

use iced::{Element, Sandbox, Settings};
use iced::widget::TextInput;

struct App;

impl Sandbox for App {
    type Message = ();
    fn new() -> Self { App }
    fn title(&self) -> String { "Swash Crash".to_string() }
    fn update(&mut self, _message: Self::Message) {}
    fn view(&self) -> Element<'_, Self::Message> {
        TextInput::new("Placeholder", "Value").into()
    }
}

fn main() -> iced::Result { App::run(Settings::default()) }

The program crashes. According to the log, the crash happens in swash during font processing.

Note: the crash is reproducible in Windows Sandbox (which comes with only the fonts that Microsoft ships with Windows), so the issue should not be about the custom fonts I installed.

What is the expected behavior?

Run without crash.

Version

master

Operative System

Windows

Do you have any log output?

thread 'main' panicked at 'misaligned pointer dereference: address must be a multiple of 0x2 but is 0x25ace2382a5', $HOME\.cargo\registry\src\mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd\swash-0.1.6\src\internal\parse.rs:452:13
stack backtrace:
   0: std::panicking::begin_panic_handler
             at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library\std\src\panicking.rs:578
   1: core::panicking::panic_fmt
             at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library\core\src\panicking.rs:67
   2: core::panicking::panic_misaligned_pointer_dereference
             at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library\core\src\panicking.rs:174
   3: swash::internal::parse::impl$9::from_be_data_unchecked
             at $HOME\.cargo\registry\src\mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd\swash-0.1.6\src\internal\parse.rs:452
   4: swash::internal::parse::FromBeData::from_be_data
             at $HOME\.cargo\registry\src\mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd\swash-0.1.6\src\internal\parse.rs:424
   5: swash::internal::parse::Bytes::read
             at $HOME\.cargo\registry\src\mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd\swash-0.1.6\src\internal\parse.rs:55
   6: swash::scale::cff::cff::IndexMetadata::unpack
             at $HOME\.cargo\registry\src\mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd\swash-0.1.6\src\scale\cff\cff.rs:1191
   7: swash::scale::cff::cff::Index::new
             at $HOME\.cargo\registry\src\mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd\swash-0.1.6\src\scale\cff\cff.rs:1226
   8: swash::scale::cff::cff::CffProxy::parse
             at $HOME\.cargo\registry\src\mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd\swash-0.1.6\src\scale\cff\cff.rs:92
   9: swash::scale::cff::cff::CffProxy::from_font
             at $HOME\.cargo\registry\src\mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd\swash-0.1.6\src\scale\cff\cff.rs:54
  10: swash::scale::proxy::ScalerProxy::from_font
             at $HOME\.cargo\registry\src\mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd\swash-0.1.6\src\scale\proxy.rs:28
  11: swash::scale::impl$3::new::closure$0<swash::font::FontRef>
             at $HOME\.cargo\registry\src\mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd\swash-0.1.6\src\scale\mod.rs:351
  12: swash::cache::FontCache<swash::scale::proxy::ScalerProxy>::get<swash::scale::proxy::ScalerProxy,swash::scale::impl$3::new::closure_env$0<swash::font::FontRef> >
             at $HOME\.cargo\registry\src\mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd\swash-0.1.6\src\cache.rs:50
  13: swash::scale::ScalerBuilder::new<swash::font::FontRef>
             at $HOME\.cargo\registry\src\mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd\swash-0.1.6\src\scale\mod.rs:349
  14: swash::scale::ScaleContext::builder<swash::font::FontRef>
             at $HOME\.cargo\registry\src\mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd\swash-0.1.6\src\scale\mod.rs:325
  15: cosmic_text::swash::swash_image
             at $HOME\.cargo\git\checkouts\cosmic-text-ea4fb601986df06b\b85d6a4\src\swash.rs:32
  16: cosmic_text::swash::SwashCache::get_image_uncached
             at $HOME\.cargo\git\checkouts\cosmic-text-ea4fb601986df06b\b85d6a4\src\swash.rs:115
  17: glyphon::text_render::TextRenderer::prepare_with_depth<core::iter::adapters::filter_map::FilterMap<core::iter::adapters::zip::Zip<core::slice::iter::Iter<iced_wgpu::layer::text::Text>,core::slice::iter::Iter<u64> >,iced_wgpu::text::impl$0::prepare::closur
             at $HOME\.cargo\git\checkouts\glyphon-70ff9ac92aaa9d8a\f145067\src\text_render.rs:103
  18: glyphon::text_render::TextRenderer::prepare<core::iter::adapters::filter_map::FilterMap<core::iter::adapters::zip::Zip<core::slice::iter::Iter<iced_wgpu::layer::text::Text>,core::slice::iter::Iter<u64> >,iced_wgpu::text::impl$0::prepare::closure_env$1> >
             at $HOME\.cargo\git\checkouts\glyphon-70ff9ac92aaa9d8a\f145067\src\text_render.rs:347
  19: iced_wgpu::text::Pipeline::prepare
             at $HOME\.cargo\git\checkouts\iced-f01cba4d5e61fd0a\fcb1b45\wgpu\src\text.rs:170
  20: iced_wgpu::backend::Backend::prepare_text
             at $HOME\.cargo\git\checkouts\iced-f01cba4d5e61fd0a\fcb1b45\wgpu\src\backend.rs:141
  21: iced_wgpu::backend::Backend::present<alloc::string::String>
             at $HOME\.cargo\git\checkouts\iced-f01cba4d5e61fd0a\fcb1b45\wgpu\src\backend.rs:99
  22: iced_wgpu::window::compositor::present<enum2$<iced_style::theme::Theme>,alloc::string::String>
             at $HOME\.cargo\git\checkouts\iced-f01cba4d5e61fd0a\fcb1b45\wgpu\src\window\compositor.rs:172
  23: iced_renderer::compositor::impl$0::present::closure$0<enum2$<iced_style::theme::Theme>,alloc::string::String>
             at $HOME\.cargo\git\checkouts\iced-f01cba4d5e61fd0a\fcb1b45\renderer\src\compositor.rs:122
  24: iced_graphics::renderer::Renderer<enum2$<iced_renderer::backend::Backend>,enum2$<iced_style::theme::Theme> >::with_primitives<enum2$<iced_renderer::backend::Backend>,enum2$<iced_style::theme::Theme>,enum2$<core::result::Result<tuple$<>,iced_graphics::comp
             at $HOME\.cargo\git\checkouts\iced-f01cba4d5e61fd0a\fcb1b45\graphics\src\renderer.rs:51
  25: iced_renderer::compositor::impl$0::present<enum2$<iced_style::theme::Theme>,alloc::string::String>
             at $HOME\.cargo\git\checkouts\iced-f01cba4d5e61fd0a\fcb1b45\renderer\src\compositor.rs:103
  26: iced_winit::application::run_instance::async_fn$0<iced::application::Instance<bin_data_inspector::App>,iced_futures::backend::null::Executor,enum2$<iced_renderer::compositor::Compositor<enum2$<iced_style::theme::Theme> > > >
             at $HOME\.cargo\git\checkouts\iced-f01cba4d5e61fd0a\fcb1b45\winit\src\application.rs:532
  27: iced_winit::application::run::closure$1<iced::application::Instance<bin_data_inspector::App>,iced_futures::backend::null::Executor,enum2$<iced_renderer::compositor::Compositor<enum2$<iced_style::theme::Theme> > > >
             at $HOME\.cargo\git\checkouts\iced-f01cba4d5e61fd0a\fcb1b45\winit\src\application.rs:251
  28: winit::platform_impl::platform::event_loop::impl$3::run_return::closure$0<tuple$<>,iced_winit::application::run::closure_env$1<iced::application::Instance<bin_data_inspector::App>,iced_futures::backend::null::Executor,enum2$<iced_renderer::compositor::Com
             at $HOME\.cargo\git\checkouts\winit-57d3141eaf559308\ac1ddfe\src\platform_impl\windows\event_loop.rs:260
  29: alloc::boxed::impl$46::call_mut<tuple$<enum2$<winit::event::Event<tuple$<> > >,ref_mut$<enum2$<winit::event_loop::ControlFlow> > >,dyn$<core::ops::function::FnMut<tuple$<enum2$<winit::event::Event<tuple$<> > >,ref_mut$<enum2$<winit::event_loop::ControlFlo
             at /rustc/90c541806f23a127002de5b4038be731ba1458ca\library\alloc\src\boxed.rs:1980
  30: winit::platform_impl::platform::event_loop::runner::impl$3::call_event_handler::closure$0<tuple$<> >
             at $HOME\.cargo\git\checkouts\winit-57d3141eaf559308\ac1ddfe\src\platform_impl\windows\event_loop\runner.rs:250
  31: core::panic::unwind_safe::impl$23::call_once<tuple$<>,winit::platform_impl::platform::event_loop::runner::impl$3::call_event_handler::closure_env$0<tuple$<> > >
             at /rustc/90c541806f23a127002de5b4038be731ba1458ca\library\core\src\panic\unwind_safe.rs:271
  32: std::panicking::try::do_call<core::panic::unwind_safe::AssertUnwindSafe<winit::platform_impl::platform::event_loop::runner::impl$3::call_event_handler::closure_env$0<tuple$<> > >,tuple$<> >
             at /rustc/90c541806f23a127002de5b4038be731ba1458ca\library\std\src\panicking.rs:485
  33: winit::platform_impl::platform::icon::impl$8::clone
  34: std::panicking::try<tuple$<>,core::panic::unwind_safe::AssertUnwindSafe<winit::platform_impl::platform::event_loop::runner::impl$3::call_event_handler::closure_env$0<tuple$<> > > >
             at /rustc/90c541806f23a127002de5b4038be731ba1458ca\library\std\src\panicking.rs:449
  35: std::panic::catch_unwind<core::panic::unwind_safe::AssertUnwindSafe<winit::platform_impl::platform::event_loop::runner::impl$3::call_event_handler::closure_env$0<tuple$<> > >,tuple$<> >
             at /rustc/90c541806f23a127002de5b4038be731ba1458ca\library\std\src\panic.rs:140
  36: winit::platform_impl::platform::event_loop::runner::EventLoopRunner<tuple$<> >::catch_unwind<tuple$<>,tuple$<>,winit::platform_impl::platform::event_loop::runner::impl$3::call_event_handler::closure_env$0<tuple$<> > >
             at $HOME\.cargo\git\checkouts\winit-57d3141eaf559308\ac1ddfe\src\platform_impl\windows\event_loop\runner.rs:157
  37: winit::platform_impl::platform::event_loop::runner::EventLoopRunner<tuple$<> >::call_event_handler<tuple$<> >
             at $HOME\.cargo\git\checkouts\winit-57d3141eaf559308\ac1ddfe\src\platform_impl\windows\event_loop\runner.rs:242
  38: winit::platform_impl::platform::event_loop::runner::EventLoopRunner<tuple$<> >::send_event<tuple$<> >
             at $HOME\.cargo\git\checkouts\winit-57d3141eaf559308\ac1ddfe\src\platform_impl\windows\event_loop\runner.rs:215
  39: winit::platform_impl::platform::event_loop::WindowData<tuple$<> >::send_event<tuple$<> >
             at $HOME\.cargo\git\checkouts\winit-57d3141eaf559308\ac1ddfe\src\platform_impl\windows\event_loop.rs:142
  40: winit::platform_impl::platform::event_loop::public_window_callback_inner::closure$0<tuple$<> >
             at $HOME\.cargo\git\checkouts\winit-57d3141eaf559308\ac1ddfe\src\platform_impl\windows\event_loop.rs:1125
  41: core::ops::function::FnOnce::call_once<winit::platform_impl::platform::event_loop::public_window_callback_inner::closure_env$0<tuple$<> >,tuple$<> >
             at /rustc/90c541806f23a127002de5b4038be731ba1458ca\library\core\src\ops\function.rs:250
  42: core::panic::unwind_safe::impl$23::call_once<isize,winit::platform_impl::platform::event_loop::public_window_callback_inner::closure_env$0<tuple$<> > >
             at /rustc/90c541806f23a127002de5b4038be731ba1458ca\library\core\src\panic\unwind_safe.rs:271
  43: std::panicking::try::do_call<core::panic::unwind_safe::AssertUnwindSafe<winit::platform_impl::platform::event_loop::public_window_callback_inner::closure_env$0<tuple$<> > >,isize>
             at /rustc/90c541806f23a127002de5b4038be731ba1458ca\library\std\src\panicking.rs:485
  44: std::panicking::try::do_catch<core::panic::unwind_safe::AssertUnwindSafe<winit::platform_impl::platform::window::impl$4::on_nccreate::closure_env$0<tuple$<> > >,tuple$<winit::platform_impl::platform::window::Window,winit::platform_impl::platform::event_lo
  45: std::panicking::try<isize,core::panic::unwind_safe::AssertUnwindSafe<winit::platform_impl::platform::event_loop::public_window_callback_inner::closure_env$0<tuple$<> > > >
             at /rustc/90c541806f23a127002de5b4038be731ba1458ca\library\std\src\panicking.rs:449
  46: std::panic::catch_unwind<core::panic::unwind_safe::AssertUnwindSafe<winit::platform_impl::platform::event_loop::public_window_callback_inner::closure_env$0<tuple$<> > >,isize>
             at /rustc/90c541806f23a127002de5b4038be731ba1458ca\library\std\src\panic.rs:140
  47: winit::platform_impl::platform::event_loop::runner::EventLoopRunner<tuple$<> >::catch_unwind<tuple$<>,isize,winit::platform_impl::platform::event_loop::public_window_callback_inner::closure_env$0<tuple$<> > >
             at $HOME\.cargo\git\checkouts\winit-57d3141eaf559308\ac1ddfe\src\platform_impl\windows\event_loop\runner.rs:157
  48: winit::platform_impl::platform::event_loop::public_window_callback_inner<tuple$<> >
             at $HOME\.cargo\git\checkouts\winit-57d3141eaf559308\ac1ddfe\src\platform_impl\windows\event_loop.rs:2320
  49: winit::platform_impl::platform::event_loop::public_window_callback<tuple$<> >
             at $HOME\.cargo\git\checkouts\winit-57d3141eaf559308\ac1ddfe\src\platform_impl\windows\event_loop.rs:994
  50: DispatchMessageW
  51: DispatchMessageW
  52: GetClassLongW
  53: KiUserCallbackDispatcher
  54: NtUserDispatchMessage
  55: DispatchMessageW
  56: winit::platform_impl::platform::event_loop::EventLoop<tuple$<> >::run_return<tuple$<>,iced_winit::application::run::closure_env$1<iced::application::Instance<bin_data_inspector::App>,iced_futures::backend::null::Executor,enum2$<iced_renderer::compositor::
             at $HOME\.cargo\git\checkouts\winit-57d3141eaf559308\ac1ddfe\src\platform_impl\windows\event_loop.rs:282
  57: winit::platform::run_return::impl$0::run_return<tuple$<>,iced_winit::application::run::closure_env$1<iced::application::Instance<bin_data_inspector::App>,iced_futures::backend::null::Executor,enum2$<iced_renderer::compositor::Compositor<enum2$<iced_style:
             at $HOME\.cargo\git\checkouts\winit-57d3141eaf559308\ac1ddfe\src\platform\run_return.rs:51
  58: iced_winit::application::platform::run<tuple$<>,iced_winit::application::run::closure_env$1<iced::application::Instance<bin_data_inspector::App>,iced_futures::backend::null::Executor,enum2$<iced_renderer::compositor::Compositor<enum2$<iced_style::theme::T
             at $HOME\.cargo\git\checkouts\iced-f01cba4d5e61fd0a\fcb1b45\winit\src\application.rs:887
  59: iced_winit::application::run<iced::application::Instance<bin_data_inspector::App>,iced_futures::backend::null::Executor,enum2$<iced_renderer::compositor::Compositor<enum2$<iced_style::theme::Theme> > > >
             at $HOME\.cargo\git\checkouts\iced-f01cba4d5e61fd0a\fcb1b45\winit\src\application.rs:226
  60: iced::application::Application::run<bin_data_inspector::App>
             at $HOME\.cargo\git\checkouts\iced-f01cba4d5e61fd0a\fcb1b45\src\application.rs:208
  61: iced::sandbox::Sandbox::run<bin_data_inspector::App>
             at $HOME\.cargo\git\checkouts\iced-f01cba4d5e61fd0a\fcb1b45\src\sandbox.rs:153

[hecrj]

Your swash dependency seems to be outdated. Run cargo update and try again. Reopen the issue if it persists!

[ruifengx]

Thanks, updating swash makes the crash go away. I actually did a cargo upgrade and thought it would imply cargo update, but it turns out not to be the case.

However, the crash itself still looks very confusing to me. I do not usually see a runtime behaviour change caused by rustc upgrade. Perhaps something in swash (or their dependencies) relies on compiler implementation details. Let's see if the developers for swash could have a further investigation.