nss_db: Fix initialization of iteration position (#1344480)

glibc-rh1344480.patch

@@ -0,0 +1,43 @@
+commit 809cde4a640032f2f87319c9358be4fee8d6d7d5
+Author: Florian Weimer <fweimer@redhat.com>
+Date:   Sat Jun 11 12:12:56 2016 +0200
+
+    nss_db: Fix initialization of iteration position [BZ #20237]
+    
+    When get*ent is called without a preceding set*ent, we need
+    to set the initial iteration position in get*ent.
+    
+    Reproducer: Add “services: db files” to /etc/nsswitch.conf, then run
+    “perl -e getservent”.  It will segfault before this change, and exit
+    silently after it.
+    
+    (cherry picked from commit 31d0a4fa646db8b8c97ce24e0ec0a7b73de4fca1)
+
+diff --git a/nss/nss_db/db-XXX.c b/nss/nss_db/db-XXX.c
+index 4a0766a..70b58be 100644
+--- a/nss/nss_db/db-XXX.c
++++ b/nss/nss_db/db-XXX.c
+@@ -77,7 +77,7 @@ CONCAT(_nss_db_set,ENTNAME) (int stayopen)
+       keep_db |= stayopen;
+ 
+       /* Reset the sequential index.  */
+-      entidx  = (const char *) state.header + state.header->valstroffset;
++      entidx  = NULL;
+     }
+ 
+   __libc_lock_unlock (lock);
+@@ -253,8 +253,14 @@ CONCAT(_nss_db_get,ENTNAME_r) (struct STRUCTURE *result, char *buffer,
+ 	  H_ERRNO_SET (NETDB_INTERNAL);
+ 	  goto out;
+ 	}
++      entidx = NULL;
+     }
+ 
++  /* Start from the beginning if freshly initialized or reset
++     requested by set*ent.  */
++  if (entidx == NULL)
++    entidx = (const char *) state.header + state.header->valstroffset;
++
+   status = NSS_STATUS_UNAVAIL;
+   if (state.header != MAP_FAILED)
+     {

glibc.spec

@@ -275,6 +275,7 @@ Patch1054: glibc-rh1352625.patch
 Patch1055: glibc-rh1348620.patch
 Patch1056: glibc-swbz20435.patch
 Patch1057: glibc-rh1294574.patch
+Patch1058: glibc-rh1344480.patch
 
 ##############################################################################
 #
@@ -749,6 +750,7 @@ microbenchmark tests on the system.
 %patch1055 -p1
 %patch1056 -p1
 %patch1057 -p1
+%patch1058 -p1
 %patch0059 -p1
 
 ##############################################################################
@@ -1975,6 +1977,7 @@ rm -f *.filelist*
 - malloc: Avoid premature fallback to mmap (#1348620)
 - CVE-2016-6323: Backtraces can hang on ARM EABI (32-bit) (swbz#20435)
 - Return proper status from _nss_nis_initgroups_dyn (#1294574)
+- nss_db: Fix initialization of iteration position (#1344480)
 
 * Thu Jun  2 2016 Florian Weimer <fweimer@redhat.com> - 2.22-17
 - CVE-2016-4429: stack overflow in Sun RPC clntudp_call (#1337140)