New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

ZDICT_trainFromBuffer_cover is not thread safe #4045

Open

as-com opened this issue May 14, 2024 · 0 comments

as-com commented May 14, 2024

Describe the bug

ZDICT_trainFromBuffer_cover is not thread safe due to the use of global state:

zstd/lib/dictBuilder/cover.c

Lines 235 to 236 in 78955f5

    
           /* We need a global context for qsort... */ 
        
           static COVER_ctx_t *g_coverCtx = NULL;

Calling this function from multiple threads may result in segfault/access violation, use-after-free and other badness.

To Reproduce
Call ZDICT_trainFromBuffer_cover from multiple threads

Desktop (please complete the following information):

OS: Windows
Version 11 23H2
Compiler: MSVC, Visual Studio 2022
Flags: default
Other relevant hardware specs: N/A
Build system: whatever zstd-sys/cargo uses

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment