bindresvport() uses two static variables port and startport which are not

protected. It is not safe when in multithread circumstance.

bindresvport() select a port number from the range 512 to 1023, when in
multithread circumstance, the port may be 1024. So the static variables will be
protected.

Signed-off-by: Peng Haitao <penght@cn.fujitsu.com>
Reviewed-by: Carlos O'Donell <carlos@systemhalted.org>

ChangeLog

@@ -1,3 +1,8 @@
+2012-11-19  Peng Haitao  <penght@cn.fujitsu.com>
+
+	[BZ #13763]
+	* sunrpc/bindrsvprt.c: Add lock to protect static variable.
+
 2012-11-19  Steve McIntyre  <steve.mcintyre@linaro.org>
 
 	* sysdeps/generic/ldconfig.h (FLAG_AARCH64_LIB64): New macro.

NEWS

@@ -12,15 +12,15 @@ Version 2.17
   1349, 3439, 3479, 3665, 5044, 5246, 5298, 5400, 6530, 6778, 6808, 9685,
   9914, 10014, 10038, 10631, 10873, 11438, 11607, 11638, 11741, 12140,
   13412, 13542, 13601, 13603, 13604, 13629, 13679, 13696, 13698, 13717,
-  13741, 13939, 13950, 13952, 13966, 14042, 14047, 14090, 14150, 14151,
-  14152, 14154, 14157, 14166, 14173, 14195, 14237, 14251, 14252, 14283,
-  14298, 14303, 14307, 14328, 14331, 14336, 14337, 14347, 14349, 14368,
-  14376, 14417, 14459, 14476, 14477, 14501, 14505, 14510, 14516, 14518,
-  14519, 14530, 14532, 14538, 14543, 14544, 14545, 14557, 14562, 14568,
-  14576, 14579, 14583, 14587, 14595, 14602, 14610, 14621, 14638, 14645,
-  14648, 14652, 14660, 14661, 14669, 14672, 14683, 14694, 14716, 14743,
-  14767, 14783, 14784, 14785, 14793, 14796, 14797, 14801, 14805, 14807,
-  14809, 14811, 14815, 14821, 14824, 14828, 14831, 14838.
+  13741, 13763, 13939, 13950, 13952, 13966, 14042, 14047, 14090, 14150,
+  14151, 14152, 14154, 14157, 14166, 14173, 14195, 14237, 14251, 14252,
+  14283, 14298, 14303, 14307, 14328, 14331, 14336, 14337, 14347, 14349,
+  14368, 14376, 14417, 14459, 14476, 14477, 14501, 14505, 14510, 14516,
+  14518, 14519, 14530, 14532, 14538, 14543, 14544, 14545, 14557, 14562,
+  14568, 14576, 14579, 14583, 14587, 14595, 14602, 14610, 14621, 14638,
+  14645, 14648, 14652, 14660, 14661, 14669, 14672, 14683, 14694, 14716,
+  14743, 14767, 14783, 14784, 14785, 14793, 14796, 14797, 14801, 14805,
+  14807, 14809, 14811, 14815, 14821, 14824, 14828, 14831, 14838.
 
 * Port to ARM AArch64 contributed by Linaro.
 

sunrpc/bindrsvprt.c

@@ -35,6 +35,12 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
+#include <bits/libc-lock.h>
+
+/*
+ * Locks the static variables in this file.
+ */
+__libc_lock_define_initialized (static, lock);
 
 /*
  * Bind a socket to a privileged IP port
@@ -74,6 +80,9 @@ bindresvport (int sd, struct sockaddr_in *sin)
 
   int nports = ENDPORT - startport + 1;
   int endport = ENDPORT;
+
+  __libc_lock_lock (lock);
+
  again:
   for (i = 0; i < nports; ++i)
     {
@@ -94,6 +103,8 @@ bindresvport (int sd, struct sockaddr_in *sin)
       goto again;
     }
 
+  __libc_lock_unlock (lock);
+
   return res;
 }
 libc_hidden_def (bindresvport)