fix(sign): reject invalid UTF‑8 dbfile token #7589
Merged
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1. Why is this pull request needed and what does it do?
The coredns/caddy lexer replaces invalid UTF‑8 bytes in tokens with U+FFFD. When that lossy-decoded value is used as
dbfilein the sign plugin, the source zone file path never exists. On startup/refresh, theresign()function sees the signed file missing and triggers signing. ConsequentlySign()then fails opening the bogus path, the signed file is never created, and the cycle repeats across all expanded origins (e.g., reverse CIDRs), causing unbounded churn/OOM.Validate
dbfilein setup and error if it contains U+FFFD. Add a regression test.Note: Unicode paths are supported; only U+FFFD (replacement-rune) is rejected.
2. Which issues (if any) are related?
Fixes OSS-Fuzz finding #448571099 (not publicly accessible yet).
3. Which documentation changes (if any) need to be made?
None.
4. Does this introduce a backward incompatible change or deprecation?
No.