From: "Sebastien Tardif via GitGitGadget" <gitgitgadget@gmail•com>
To: git@vger•kernel.org
Cc: Patrick Steinhardt <ps@pks•im>,
Sebastien Tardif <sebtardif@ncf•ca>,
Sebastien Tardif <sebtardif@ncf•ca>
Subject: [PATCH v2 1/3] daemon: fix IPv6 address corruption in lookup_hostname()
Date: Wed, 27 May 2026 18:18:29 +0000 [thread overview]
Message-ID: <b2d81438117a716417a031c74b678a8f91701af4.1779905911.git.gitgitgadget@gmail.com> (raw)
In-Reply-To: <pull.2300.v2.git.git.1779905911.gitgitgadget@gmail.com>
From: Sebastien Tardif <sebtardif@ncf•ca>
getaddrinfo() is called with AF_UNSPEC hints, so it may return IPv6
results. However, the code unconditionally casts ai_addr to
sockaddr_in and passes AF_INET to inet_ntop(). On IPv6-only hosts,
this reads from the wrong struct offset, producing garbage IP
addresses.
Fix this by checking ai_family and extracting the address pointer
into a local variable before calling inet_ntop() once with the
correct family. Die on unexpected address families.
Signed-off-by: Sebastien Tardif <sebtardif@ncf•ca>
---
daemon.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/daemon.c b/daemon.c
index 0a7b1aae44..80fa0226d8 100644
--- a/daemon.c
+++ b/daemon.c
@@ -674,9 +674,20 @@ static void lookup_hostname(struct hostinfo *hi)
gai = getaddrinfo(hi->hostname.buf, NULL, &hints, &ai);
if (!gai) {
- struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
+ void *addr;
+
+ if (ai->ai_family == AF_INET) {
+ struct sockaddr_in *sa = (void *)ai->ai_addr;
+ addr = &sa->sin_addr;
+ } else if (ai->ai_family == AF_INET6) {
+ struct sockaddr_in6 *sa6 = (void *)ai->ai_addr;
+ addr = &sa6->sin6_addr;
+ } else {
+ die("unexpected address family: %d",
+ ai->ai_family);
+ }
- inet_ntop(AF_INET, &sin_addr->sin_addr,
+ inet_ntop(ai->ai_family, addr,
addrbuf, sizeof(addrbuf));
strbuf_addstr(&hi->ip_address, addrbuf);
--
gitgitgadget
next prev parent reply other threads:[~2026-05-27 18:18 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-14 15:46 [PATCH 0/3] daemon: fix network address handling bugs Sebastien Tardif via GitGitGadget
2026-05-14 15:46 ` [PATCH 1/3] daemon: fix IPv6 address corruption in lookup_hostname() Sebastien Tardif via GitGitGadget
2026-05-14 21:26 ` Junio C Hamano
2026-05-14 15:46 ` [PATCH 2/3] daemon: fix IPv6 address truncation in ip2str() Sebastien Tardif via GitGitGadget
2026-05-14 15:46 ` [PATCH 3/3] daemon: guard NULL REMOTE_PORT in execute() logging Sebastien Tardif via GitGitGadget
2026-05-14 19:20 ` [PATCH 0/3] daemon: fix network address handling bugs Junio C Hamano
2026-05-15 7:31 ` Patrick Steinhardt
2026-05-27 18:18 ` [PATCH v2 " Sebastien Tardif via GitGitGadget
2026-05-27 18:18 ` Sebastien Tardif via GitGitGadget [this message]
2026-05-27 18:18 ` [PATCH v2 2/3] daemon: fix IPv6 address truncation in ip2str() Sebastien Tardif via GitGitGadget
2026-05-27 18:18 ` [PATCH v2 3/3] daemon: guard NULL REMOTE_PORT in execute() logging Sebastien Tardif via GitGitGadget
2026-05-27 21:00 ` [PATCH v2 0/3] daemon: fix network address handling bugs Junio C Hamano
2026-05-28 2:56 ` [PATCH v3 " Sebastien Tardif via GitGitGadget
2026-05-28 2:56 ` [PATCH v3 1/3] daemon: fix IPv6 address corruption in lookup_hostname() Sebastien Tardif via GitGitGadget
2026-05-28 2:56 ` [PATCH v3 2/3] daemon: fix IPv6 address truncation in ip2str() Sebastien Tardif via GitGitGadget
2026-05-28 2:56 ` [PATCH v3 3/3] daemon: guard NULL REMOTE_PORT in execute() logging Sebastien Tardif via GitGitGadget
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=b2d81438117a716417a031c74b678a8f91701af4.1779905911.git.gitgitgadget@gmail.com \
--to=gitgitgadget@gmail$(echo .)com \
--cc=git@vger$(echo .)kernel.org \
--cc=ps@pks$(echo .)im \
--cc=sebtardif@ncf$(echo .)ca \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox