{"id":"RUSTSEC-2026-0302","summary":"`stack-graphs` C API exports are safe `extern \"C\"` functions","details":"`stack_graphs::c` is a public module. From 0.0.3 through the current crates.io release 0.14.1, its pointer-taking entry points are `pub extern \"C\" fn` rather than `unsafe fn`. Safe Rust can call them.\n\n`sg_stack_graph_free` frees the pointer with `Box::from_raw`. `sg_stack_graph_free(std::ptr::null_mut())` is immediate undefined behavior. The same shape is used by the other `*_free` exports and by getters and mutators that dereference the caller-supplied pointer or pass it to `from_raw_parts` (`sg_stack_graph_nodes`, `sg_stack_graph_add_edges`, and the rest of the pointer-taking functions in `src/c.rs`). Constructors that take no pointer are not part of this issue.\n\nThe upstream repository is archived, so a fix cannot be filed there and no patched release exists. The soundness fix is to make every pointer-taking export `unsafe extern \"C\" fn`, with a safety comment that the pointer is non-null and, for `free`, came from the matching constructor.","modified":"2026-09-22T21:00:02.879515742Z","published":"2026-09-22T12:00:00Z","database_specific":{"license":"CC0-1.0"},"references":[{"type":"PACKAGE","url":"https://crates.io/crates/stack-graphs"},{"type":"ADVISORY","url":"https://rustsec.org/advisories/RUSTSEC-2026-0302.html"},{"type":"REPORT","url":"https://github.com/rustsec/advisory-db/issues/3241"},{"type":"WEB","url":"https://github.com/github/stack-graphs"}],"affected":[{"package":{"name":"stack-graphs","ecosystem":"crates.io","purl":"pkg:cargo/stack-graphs"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.0.3-0"}]}],"ecosystem_specific":{"affects":{"arch":[],"os":[],"functions":["stack_graphs::c::sg_stack_graph_free"]},"affected_functions":null},"database_specific":{"categories":["memory-corruption"],"cvss":null,"informational":"unsound","source":"https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0302.json"}}],"schema_version":"1.9.0"}