match_hostname() did a forward-DNS lookup of a config-specified hostname
token and, on gethostbyname() failure, returned "no match" -- which
allow_access() cannot distinguish from a real non-match, so a daemon with
"hosts deny = <hostname>" silently admitted the host whenever the token
could not resolve (a resolver-less chroot, or a transient DNS failure).
No attacker DNS control required.
Thread a deny flag through access_match()/match_hostname() and, on a
forward-DNS failure, treat an unresolvable DENY-list token as a match so
the connection is refused (fail closed); allow-list tokens still fail as a
non-match. Sibling of CVE-2026-43617, which fixed only the reverse path.
Reported-by: Leonid Bugaev <leonsbox@gmail.com>
(cherry picked from commit 84e469ea03a98ef31326d3d861336d7e7d582ce1)
- io: bound daemon argument lists so a malicious daemon client cannot grow
argv without limit (DoS);
- socket: bound the PROXY CONNECT request and proxy response header lines;
- daemon: require a trusted-proxy host list for "proxy protocol = true"
(reject untrusted proxy peers, fail-closed), and warn at startup when the
trusted-proxy list is unset so the fail-closed behaviour is not silent.
Tests: daemon-argv-limit, proxy-connect-request-too-long,
proxy-response-header-too-long, proxy-protocol-trusted-peer.
Glibc 2.43 added C23 const-preserving overloads to various string functions,
which change the return type depending on the constness of the argument(s).
Currently this leads to warnings from calls to strtok() or strchr().
Fix this by properly declaring the respective variable types.
Signed-off-by: Holger Hoffstätte <holger@applied-asynchrony.com>
- All the memory-allocation macros now auto-check for failure and exit
with a failure message that incudes the caller's file and lineno
info. This includes strdup().
- Added the `--max-alloc=SIZE` option to be able to override the memory
allocator's sanity-check limit. It defaults to 1G (as before).
Fixes bugzilla bug 12769.
- Standardized the format of the opening comment, including adding a
brief description of what's in the file for those that lacked it.
- Added some missing copyright lines.
- Some minor whitespace tweaks (in a few of the files).
Andrew Tridgell