A bug in Rust 1.98.0 sometimes results in rustc incorrectly generating a trait object vtable with a null pointer, resulting in a crash.
Hot on the heels of the Rust 1.98.0 release, the Rust team has published Rust 1.98.1, an update that fixes a miscompilation in vtable generation.
Rust 1.98.1 was announced September 3.
A Rust issue opened August 21 (and now closed) noted that Rust 1.98 emits a zero method entry in a compiler-generated vtable, resulting in a segmentation fault and a crash. According to the Rust 1.98.1 release notes:
In Rust 1.98.0, in some circumstances, rustc would incorrectly generate a trait object vtable with a null pointer where a function pointer should be. This leads to undefined behavior in the emitted code. In some cases this may “just” cause segfaults due to the null pointer being loaded, but it is possible for it to be justification for arbitrary effects.
This bug is fixed in Rust 1.98.1. The Rust 1.98.0 release brought algebraic methods for addition, subtraction, multiplication, division, and remainder to floating-point types, allowing optimizations on these operations using algebraic properties of real number.
Users of a previous version of Rust installed via rustup can install Rust 1.98.1 by running the command rustup update stable. The Rust team asks developers who would like to help test future releases to consider using the beta (rustup default beta) and nightly (rustup default nightly) channels and to please report any bugs.
