From: Aki Tuomi <aki.tuomi@dovecot.fi>
Date: Fri, 5 Oct 2018 07:18:35 +0000 (+0300)
Subject: userdb-passwd: Fix getpwent errno handling
X-Git-Tag: 2.3.8~193
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0c222e2961569462011af3e6fab7e7b6910003fc;p=thirdparty%2Fdovecot%2Fcore.git

userdb-passwd: Fix getpwent errno handling

In https://bugs.gentoo.org/667118 Reuben Farrelly
noticed that running
    # doveadm user '*'
causes auth daemon to generate errors like:
    auth-worker(3585): Error: getpwent() failed: Invalid argument

This happens because on successful call getpwent()
now sets errno=EINVAL starting from glibc-2.28.
See https://sourceware.org/PR16004 for details.

The fix is to reset 'errno' before 'getpwent()' is called.

Reported-by: Reuben Farrelly
Bug: https://bugs.gentoo.org/667118
Bug: https://sourceware.org/PR16004
Original-Author: Sergei Trofimovich <slyfox@gentoo.org>
---

diff --git a/src/auth/userdb-passwd.c b/src/auth/userdb-passwd.c
index d0f8b680aa..fa868e6b81 100644
--- a/src/auth/userdb-passwd.c
+++ b/src/auth/userdb-passwd.c
@@ -172,12 +172,16 @@ static void passwd_iterate_next(struct userdb_iterate_context *_ctx)
 		return;
 	}
 
+	/* reset errno since it might have been set when we got here */
 	errno = 0;
 	while ((pw = getpwent()) != NULL) {
 		if (passwd_iterate_want_pw(pw, set)) {
 			_ctx->callback(pw->pw_name, _ctx->context);
 			return;
 		}
+		/* getpwent might set errno to something even if it
+		   returns non-NULL. */
+		errno = 0;
 	}
 	if (errno != 0) {
 		i_error("getpwent() failed: %m");