ac125ee29a
As proposed in #240 and tracked in #414, this PR translates all advisories into the new "V3" advisory format, which is based on Markdown with leading TOML front matter. This format makes it easier to see rendered Markdown syntax descriptions, whether rendered by an IDE or GitHub. This should help with both crafting advisories initially as well as review, and ideally encourages more lengthy descriptions. Support for this format shipped in `cargo-audit` v0.12.0 on May 6th, 2020.
1.5 KiB
[advisory]
id = "RUSTSEC-2019-0013"
package = "spin"
aliases = ["CVE-2019-16137"]
date = "2019-08-27"
keywords = ["atomic", "ordering", "spin", "lock", "mutex", "rwlock"]
url = "https://github.com/mvdnes/spin-rs/issues/65"
[affected.functions]
"spin::RwLock::new" = ["< 0.5.2"]
[versions]
patched = [">= 0.5.2"]
Wrong memory orderings in RwLock potentially violates mutual exclusion
Wrong memory orderings inside the RwLock implementation allow for two writers to acquire the lock at the same time. The drop implementation used Ordering::Relaxed, which allows the compiler or CPU to reorder a mutable access on the locked data after the lock has been yielded.
Only users of the RwLock implementation are affected. Users of Once (including users of lazy_static with the spin_no_std feature enabled) are NOT affected.
On strongly ordered CPU architectures like x86, the only real way that this would lead to a memory corruption is if the compiler reorders an access after the lock is yielded, which is possible but in practice unlikely. It is a more serious issue on weakly ordered architectures such as ARM which, except in the presence of certain instructions, allow the hardware to decide which accesses are seen at what times. Therefore on an ARM system it is likely that using the wrong memory ordering would result in a memory corruption, even if the compiler itself doesn't reorder the memory accesses in a buggy way.
The flaw was corrected by https://github.com/mvdnes/spin-rs/pull/66.