[PATCH v2] glibc: fix Segmentation fault in gethostid.c

[<mingli.yu@windriver.com>]

From: Mingli Yu <Mingli.Yu@windriver.com>

When run test program hostid, it encounters
Segmentation fault as hp is NULL.

 # cat /mybuild/hostid.c
 #include <stdio.h>
 #include <unistd.h>

 int
 main(int argc, char *argv[])
 {
    long hostid;
    hostid = gethostid();
    printf("the hostid is %ld\n", hostid);

 }

 # gcc -o /mybuild/hostid /mybuild/hostid.c
 # /mybuild/hostid
 Segmentation fault
 # gdb /mybuild/hostid
 GNU gdb (GDB) 8.2
 Copyright (C) 2018 Free Software Foundation, Inc.
 License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
 This is free software: you are free to change and redistribute it.
 There is NO WARRANTY, to the extent permitted by law.
 Type "show copying" and "show warranty" for details.
 This GDB was configured as "x86_64-wrs-linux".
 Type "show configuration" for configuration details.
 For bug reporting instructions, please see:
 <http://www.gnu.org/software/gdb/bugs/>.
 Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

 For help, type "help".
 Type "apropos word" to search for commands related to "word"...
 Reading symbols from /mybuild/hostid...done.
 (gdb) r
 Starting program: /mybuild/hostid

 Program received signal SIGSEGV, Segmentation fault.
 0x00007ffff7f0330e in gethostid () at ../sysdeps/unix/sysv/linux/gethostid.c:125
 125	  memcpy (&in, hp->h_addr,
 (gdb) bt
 #0  0x00007ffff7f0330e in gethostid () at ../sysdeps/unix/sysv/linux/gethostid.c:125
 #1  0x0000555555555159 in main ()

Signed-off-by: Mingli Yu <Mingli.Yu@windriver.com>
---
 .../0001-gethostid.c-check-the-value-of-hp.patch   | 75 ++++++++++++++++++++++
 meta/recipes-core/glibc/glibc_2.28.bb              |  1 +
 2 files changed, 76 insertions(+)
 create mode 100644 meta/recipes-core/glibc/glibc/0001-gethostid.c-check-the-value-of-hp.patch

diff --git a/meta/recipes-core/glibc/glibc/0001-gethostid.c-check-the-value-of-hp.patch b/meta/recipes-core/glibc/glibc/0001-gethostid.c-check-the-value-of-hp.patch
new file mode 100644
index 0000000000..04d1662361
--- /dev/null
+++ b/meta/recipes-core/glibc/glibc/0001-gethostid.c-check-the-value-of-hp.patch
@@ -0,0 +1,75 @@
+From 84cc79a003cf1a29e0a45ee76b67a3800d9e412e Mon Sep 17 00:00:00 2001
+From: Mingli Yu <Mingli.Yu@windriver.com>
+Date: Tue, 18 Sep 2018 07:29:27 +0000
+Subject: [PATCH] gethostid.c: check the value of hp
+
+Fix Segmentation fault in gethostid.c
+
+When run test program hostid, it encounters
+Segmentation fault as hp is NULL.
+
+  # cat /mybuild/hostid.c
+  #include <stdio.h>
+  #include <unistd.h>
+
+  int
+  main(int argc, char *argv[])
+  {
+    long hostid;
+    hostid = gethostid();
+    printf("the hostid is %ld\n", hostid);
+  }
+ 
+  # gcc -o /mybuild/hostid /mybuild/hostid.c
+  # /mybuild/hostid
+  Segmentation fault
+  # gdb /mybuild/hostid
+  GNU gdb (GDB) 8.2
+  Copyright (C) 2018 Free Software Foundation, Inc.
+  License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
+  This is free software: you are free to change and redistribute it.
+  There is NO WARRANTY, to the extent permitted by law.
+  Type "show copying" and "show warranty" for details.
+  This GDB was configured as "x86_64-wrs-linux".
+  Type "show configuration" for configuration details.
+  For bug reporting instructions, please see:
+  <http://www.gnu.org/software/gdb/bugs/>.
+  Find the GDB manual and other documentation resources online at:
+      <http://www.gnu.org/software/gdb/documentation/>.
+ 
+   For help, type "help".
+   Type "apropos word" to search for commands related to "word"...
+   Reading symbols from /mybuild/hostid...done.
+   (gdb) r
+   Starting program: /mybuild/hostid
+ 
+   Program received signal SIGSEGV, Segmentation fault.
+   0x00007ffff7f0330e in gethostid () at ../sysdeps/unix/sysv/linux/gethostid.c:125
+   125      memcpy (&in, hp->h_addr,
+   (gdb) bt
+    #0  0x00007ffff7f0330e in gethostid () at ../sysdeps/unix/sysv/linux/gethostid.c:125
+    #1  0x0000555555555159 in main ()
+
+Upstream-Status: Submitted[https://sourceware.org/bugzilla/show_bug.cgi?id=23679]
+
+Signed-off-by: Mingli Yu <Mingli.Yu@windriver.com>
+---
+ sysdeps/unix/sysv/linux/gethostid.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/sysdeps/unix/sysv/linux/gethostid.c b/sysdeps/unix/sysv/linux/gethostid.c
+index 2e20f034dc..5904b61c40 100644
+--- a/sysdeps/unix/sysv/linux/gethostid.c
++++ b/sysdeps/unix/sysv/linux/gethostid.c
+@@ -102,7 +102,7 @@ gethostid (void)
+     {
+       int ret = __gethostbyname_r (hostname, &hostbuf,
+ 				   tmpbuf.data, tmpbuf.length, &hp, &herr);
+-      if (ret == 0)
++      if (ret == 0 && hp != NULL)
+ 	break;
+       else
+ 	{
+-- 
+2.13.3
+
diff --git a/meta/recipes-core/glibc/glibc_2.28.bb b/meta/recipes-core/glibc/glibc_2.28.bb
index 0ebbaf9610..0a8fa0c25f 100644
--- a/meta/recipes-core/glibc/glibc_2.28.bb
+++ b/meta/recipes-core/glibc/glibc_2.28.bb
@@ -45,6 +45,7 @@ SRC_URI = "${GLIBC_GIT_URI};branch=${SRCBRANCH};name=glibc \
            file://0028-bits-siginfo-consts.h-enum-definition-for-TRAP_HWBKP.patch \
            file://0029-localedef-add-to-archive-uses-a-hard-coded-locale-pa.patch \
            file://0030-intl-Emit-no-lines-in-bison-generated-files.patch \
+           file://0001-gethostid.c-check-the-value-of-hp.patch \
 "
 
 NATIVESDKFIXES ?= ""
-- 
2.13.3