[PATCH 0/3] daemon: fix network address handling bugs

["Sebastien Tardif via GitGitGadget" <gitgitgadget@gmail.com>]

Fix three related issues in daemon.c's network address handling:

IPv6 address corruption in lookup_hostname(): 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. Fixed by checking ai_family and handling
both AF_INET and AF_INET6.

IPv6 address truncation in ip2str(): The sockaddr struct size (ai_addrlen)
is passed as the output buffer size to inet_ntop(). For IPv6,
sizeof(sockaddr_in6) is 28 bytes but INET6_ADDRSTRLEN is 46, so long IPv6
addresses are silently truncated. Fixed by passing sizeof(ip) instead, and
dropping the now-unused len parameter.

NULL pointer in execute() logging: REMOTE_PORT environment variable is used
in a format string without a NULL check (only REMOTE_ADDR was checked). If
REMOTE_PORT is unset, NULL is passed to printf's %s, which is undefined
behavior. Fixed by using a fallback string.

Sebastien Tardif (3):
  daemon: fix IPv6 address corruption in lookup_hostname()
  daemon: fix IPv6 address truncation in ip2str()
  daemon: guard NULL REMOTE_PORT in execute() logging

 daemon.c | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)


base-commit: 59ff4886a579f4bc91e976fe18590b9ae02c7a08
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2300%2FSebTardif%2Ffix%2Fdaemon-ipv6-and-null-port-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2300/SebTardif/fix/daemon-ipv6-and-null-port-v1
Pull-Request: https://github.com/git/git/pull/2300
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