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From 0f700cf71f5531fb6c863990216aa1eb88970dc8 Mon Sep 17 00:00:00 2001
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From: Alexander Bokovoy <abokovoy@redhat.com>
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Date: Wed, 16 Jun 2021 11:08:21 +0300
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Subject: [PATCH] back-sch-nss: only loop if asked to try again
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slapi-nis uses sss-idmap library to discover user group membership.  Its
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sss_nss_getgrouplist_timeout() function can return timeout errors as
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well which might cause a busy looping.  sss_nss_getgrouplist_timeout()
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will return ERANGE which is translated by slapi-nis to NSS_STATUS_TRYAGAIN.
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Fixes: rhbz#1967179
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Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
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---
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 src/back-sch-nss.c | 13 ++++++++-----
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 1 file changed, 8 insertions(+), 5 deletions(-)
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diff --git a/src/back-sch-nss.c b/src/back-sch-nss.c
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index df04a96..b595f3b 100644
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--- a/src/back-sch-nss.c
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+++ b/src/back-sch-nss.c
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@@ -589,19 +589,22 @@ repeat:
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 		return NULL;
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 	}
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-	do {
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+	for(rc = NSS_STATUS_TRYAGAIN; rc == NSS_STATUS_TRYAGAIN;) {
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 		rc = backend_nss_getgrouplist(ctx, user_name, pwd.pw_gid,
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 					      grouplist, &ngroups,
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 					      &lerrno);
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-		if ((rc != NSS_STATUS_SUCCESS)) {
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-			tmp_list = realloc(grouplist, ngroups * sizeof(gid_t));
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-			if (tmp_list == NULL) {
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+		if (rc == NSS_STATUS_TRYAGAIN) {
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+			tmp_list = NULL;
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+			if (lerrno == ERANGE) {
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+				tmp_list = realloc(grouplist, ngroups * sizeof(gid_t));
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+			}
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+			if ((tmp_list == NULL) || (lerrno == ENOMEM)) {
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 				free(grouplist);
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 				return NULL;
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 			}
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 			grouplist = tmp_list;
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 		}
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-	} while (rc != NSS_STATUS_SUCCESS);
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+	}
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 	entries = calloc(ngroups + 1, sizeof(entries[0]));
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 	if (entries == NULL) {
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-- 
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2.31.1
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