RUSTSEC-2018-0003

Possible double free during unwinding in SmallVec::insert_many

Reported

July 19, 2018

Issued

October 1, 2020 (last modified: June 13, 2023)

Package

smallvec (crates.io)

Type

Vulnerability

Keywords

#memory-corruption

Aliases

References

https://github.com/servo/rust-smallvec/issues/96

CVSS Score

9.8 CRITICAL

CVSS Details

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

CVSS Vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Patched

>=0.6.3
^0.3.4
^0.4.5
^0.5.1

Unaffected

<0.3.2

Description

If an iterator passed to SmallVec::insert_many panicked in Iterator::next, destructors were run during unwinding while the vector was in an inconsistent state, possibly causing a double free (a destructor running on two copies of the same value).

This is fixed in smallvec 0.6.3 by ensuring that the vector's length is not updated to include moved items until they have been removed from their original positions. Items may now be leaked if Iterator::next panics, but they will not be dropped more than once.

Thank you to @Vurich for reporting this bug.

Advisory available under CC0-1.0 license.