diff --git a/crates/glib/RUSTSEC-0000-0000.md b/crates/glib/RUSTSEC-0000-0000.md new file mode 100644 index 000000000..6f211ffc3 --- /dev/null +++ b/crates/glib/RUSTSEC-0000-0000.md @@ -0,0 +1,32 @@ +```toml +[advisory] +id = "RUSTSEC-0000-0000" +package = "glib" +date = "2024-03-30" +url = "https://github.com/gtk-rs/gtk-rs-core/pull/1343" +informational = "unsound" + +[[affected.functions]] +"glib::VariantStrIter::next" = [">=0.15.0,<0.20.0"] +"glib::VariantStrIter::nth" = [">=0.15.0,<0.20.0"] +"glib::VariantStrIter::last" = [">=0.15.0,<0.20.0"] +"glib::VariantStrIter::next_back" = [">=0.15.0,<0.20.0"] +"glib::VariantStrIter::nth_back" = [">=0.15.0,<0.20.0"] + +[versions] +patched = [">=0.20.0"] +unaffected = ["<0.15.0"] +``` + +# Unsoundness in `Iterator` and `DoubleEndedIterator` impls for `glib::VariantStrIter` + +The `VariantStrIter::impl_get` function (called internally by implementations of the `Iterator` and `DoubleEndedIterator` traits for this type) was unsound, resulting in undefined behaviour. + +An immutable reference `&p` to a `*mut libc::c_char` pointer initialized to `NULL` was passed as an argument to a C function that that mutates the pointer behind `&p` in-place (i.e. as an out-argument), which was unsound. After changes in recent versions of the Rust compiler, these unsound writes through `&p` now seem to be completely disregarded when building the `glib` crate with optimizations. + +This subsequently caused all calls of `VariantStrIter::impl_get` to violate the safety requirements of the `std::ffi::CStr::from_ptr` function - which requires its argument to be a valid pointer to a C-style string - resulting in crashes due to `NULL` pointer dereferences. + +This was fixed by passing the out-argument pointer explitly as `&mut p` instead of `&p`. + +This issue has been present since this code was initially added in `glib` v0.15.0. The mismatch in mutability was likely missed (and not raised as an error by the compiler) because the C function wrapped by `VariantStrIter::impl_get` is variadic (`glib_sys::g_variant_get_child`), and the pointer in question is one of the variadic arguments. +