libbsdconf: parse from a bounded in-memory buffer
Needs ReviewPublic
Actions

Authored by dteske on Thu, Sep 17, 12:59 AM.

Details

Reviewers

fuz
kfv

Summary

Copy the descriptor into a buffer of at most 64 MiB (raise it with
BSDCONF_MAX_BYTES) and tokenize with bsdconf_scan(), the walker
bsdconf_put() already uses. Input above the cap fails with EFBIG.
Bump libbsdconf to 2.0.0 and sysconf(8) to 2.0.

Suggested by: fuz

Diff Detail

Repository

rG FreeBSD src repository

Lint

Lint Skipped

Unit

Tests Skipped

Build Status

Buildable 77009
Build 73892: arc lint + arc unit

Event Timeline

dteske created this revision.Thu, Sep 17, 12:59 AM

Herald added subscribers: ziaee, jonathan, imp. · View Herald TranscriptThu, Sep 17, 12:59 AM

dteske requested review of this revision.Thu, Sep 17, 12:59 AM

dteske added a parent revision: D59745: libbsdconf: Remove unnecessary parens.

Harbormaster completed remote builds in B77009: Diff 186933.Thu, Sep 17, 12:59 AM

fuz added inline comments.Thu, Sep 17, 11:22 AM

lib/libbsdconf/bsdconf.h
40	Assuming we use semantic versioning here, what is the API break that requires a major version update?
lib/libbsdconf/bsdconf_stmt.c
196	This potentially stomps over the errno value reported by `read`.
206	There are some theoretical reasons why growing the cap by the golden ration (approx. 13/8) is better, but doubling the size is certainly workable.
207	This makes the intent easier to understand. Or use `ckd_mul` from `<stdckdint.h>` to check for overflow (requires C23).