From 7d568410b455390362e2bcfb7c50fcf9c8833d9b Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Mon, 1 Aug 2022 12:54:23 -0400 Subject: fix mishandling of errno in getaddrinfo AI_ADDRCONFIG logic this code attempts to use the value of errno from failure of socket or connect to infer availability of the requested address family (v4 or v6). however, in the case where connect failed, there is an intervening call to close between connect and the use of errno. close is not required to preserve errno on success, and in fact the __aio_close code, which is called whenever aio is linked and thus always called in dynamic-linked programs, unconditionally clobbers errno. as a result, getaddrinfo fails with EAI_SYSTEM and errno=ENOENT rather than correctly determining that the address family was unavailable. this fix is based on report/patch by Jussi Nieminen, but simplified slightly to avoid breaking the case where socket, not connect, failed. --- src/network/getaddrinfo.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/src/network/getaddrinfo.c b/src/network/getaddrinfo.c index efaab306..9df045f6 100644 --- a/src/network/getaddrinfo.c +++ b/src/network/getaddrinfo.c @@ -66,9 +66,11 @@ int getaddrinfo(const char *restrict host, const char *restrict serv, const stru pthread_setcancelstate( PTHREAD_CANCEL_DISABLE, &cs); int r = connect(s, ta[i], tl[i]); + int saved_errno = errno; pthread_setcancelstate(cs, 0); close(s); if (!r) continue; + errno = saved_errno; } switch (errno) { case EADDRNOTAVAIL: -- cgit v1.2.1