PT-2026-42963 · Crates.Io · Oneringbuf

Published

2026-05-14

·

Updated

2026-05-14

None

No severity ratings or metrics are available. When they are, we'll update the corresponding info on the page.
When the vmem feature is enabled, VmemStorage<T>::new(Box<[UnsafeSyncCell<T>]>) (and every public constructor that funnels through it — ConcurrentHeapRB::default(cap), ConcurrentHeapRB::from(Vec<T>), From<Box<[T]>>, etc.) bit-copies the input buffer into a freshly mmap'd region with ptr::copy nonoverlapping, then lets the source Box<[UnsafeSyncCell<T>]> drop normally.
Because UnsafeSyncCell<T> has a Drop impl that runs assume init drop on its inner MaybeUninit<T>, the source-side T values are dropped at the end of new, while bitwise duplicates (carrying the same heap pointers for String, Box, Vec, Arc, …) remain inside the mmap region. When the ring buffer is later destructed, the destructor's drop in place over the slice runs UnsafeSyncCell::drop a second time on every cell — a deterministic double-free of every heap-owning element. Reachable from 100% safe Rust.

Trigger

rust
let v: Vec<Vec<u32>> = (0..1024).map(|i| vec![i, i+1, i+2]).collect();
let rb: oneringbuf::SharedVmemRB<Vec<u32>> = oneringbuf::SharedVmemRB::from(v);
drop(rb);
// glibc: free(): double free detected in tcache 2 -> abort
// ASan: AddressSanitizer: attempting double-free
Any T with a non-trivial Drop reproduces deterministically.

Fix

Fixed in 0.7.1 via upstream PR skilvingr/rust-oneringbuf#3, which deallocates the source Box<[UnsafeSyncCell<T>]> without running per-element Drop after the bytes have been copied into the mmap region. Vulnerable versions (< 0.7.1) have been yanked from crates.io.
Found an issue in the description? Have something to add? Feel free to write us 👾

Related Identifiers

RUSTSEC-2026-0143

Affected Products

Oneringbuf