mirror of
https://github.com/jedisct1/libsodium.git
synced 2026-08-25 08:37:13 +09:00
Frank Denis
df8802b013
SUMMARY `src/libsodium/sodium/core.c` invokes the process-global misuse callback from `sodium_misuse()` while still holding the library-wide critical section. If the application-installed callback re-enters any API path that acquires the same lock, including `sodium_set_misuse_handler()`, execution deadlocks before `abort()` is reached. This breaks the intended fail-stop behavior of misuse handling. PROVENANCE Verified from the provided finding, reproduced locally from the committed control flow, and documented for Swival Security Scanner (https://swival.dev). PRECONDITIONS - A caller installs a misuse handler via `sodium_set_misuse_handler()`. - The handler re-enters an API path that takes the same global critical section, including `sodium_set_misuse_handler()`. PROOF 1. `sodium_set_misuse_handler()` writes the global `_misuse_handler` under `sodium_crit_enter()` / `sodium_crit_leave()` in `src/libsodium/sodium/core.c:170` and `src/libsodium/sodium/core.c:174`. 2. `sodium_misuse()` acquires that same critical section, copies `_misuse_handler`, and invokes `handler()` before releasing the lock in `src/libsodium/sodium/core.c:155` and `src/libsodium/sodium/core.c:160`. 3. The pthread-backed critical section in this file is non-recursive (`src/libsodium/sodium/core.c:89`), so a callback that calls `sodium_set_misuse_handler()` blocks in `sodium_crit_enter()` waiting on the lock already held by `sodium_misuse()`. 4. Because `sodium_misuse()` is waiting for the callback to return, it never reaches `abort()`, converting a fail-stop misuse path into a hang. 5. Reproduction confirmed this with a minimal pthread harness: the handler printed `handler: before reentry` and then hung until terminated by `timeout`. WHY THIS IS A REAL BUG The callback target is application-controlled through an exported setter, and `sodium_misuse()` calls it on a misuse path without enforcing any non-reentrancy contract. On pthread targets, a handler that performs a supported API call can permanently block process termination. That is a reachable behavioral failure, not a theoretical lock-order concern. FIX REQUIREMENT Load `_misuse_handler` while holding the lock, release the critical section, and only then invoke the callback. This removes lock-dependent behavior from arbitrary user code while preserving synchronized access to the global handler pointer.
Sodium is an easy-to-use software library that provides a wide range of cryptographic operations including encryption, decryption, digital signatures, and secure password hashing.
It is a portable, cross-compilable, installable, and packageable fork of NaCl. While maintaining API compatibility, libsodium extends functionality to improve usability and simplify the development of secure applications.
Key Features
- Encryption & Decryption: Securely encrypt and decrypt data with modern algorithms.
- Digital Signatures: Create and verify signatures to ensure data authenticity.
- Cross-Platform Compatibility: Supported on Windows (MinGW and Visual Studio, x86, x64 and arm64), iOS, Android, JavaScript, and WebAssembly.
- User-Friendly API: Designed to provide all core cryptographic operations while remaining easy to integrate into your projects.
Documentation
Versioning
libsodium uses a two-tier release system:
- Point releases (e.g., 1.0.19, 1.0.20, 1.0.21) are tagged when new features are added or significant changes are made.
- Stable releases are frequent maintainance updates between point releases. They fix minor issues while remaining fully compatible with their parent point release. No new features, no breaking changes.
If your application depends on a specific point release, stable updates are safe to apply. Security fixes go to the stable branch immediately, with a new point release tagged shortly after.
Contributors
Code Contributors
This project thrives thanks to the valuable contributions from our community. View all the contributors:
Financial Contributors
Your financial support helps us sustain and further develop libsodium.
Individuals
Organizations
Support libsodium with your organization and gain visibility through your logo and website link.
License
This project is distributed under the ISC license.