Bug#947808: libvncserver: Please backport small patch to fix unaligned access on sparc64

[John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>]

Source: libvncserver
Version: 0.9.12+dfsg-5
Severity: normal
Tags: patch
User: debian-sparc@lists.debian.org
Usertags: sparc64

Hi!

The testsuite of libvncserver currently crashes on sparc64 due to
unaligned access:

Running tests...
/usr/bin/ctest --force-new-ctest-process -j32
Test project /<<PKGBUILDDIR>>/obj-sparc64-linux-gnu
    Start 1: cargs
    Start 2: turbojpeg
    Start 3: wstest
1/3 Test #1: cargs ............................   Passed    0.01 sec
2/3 Test #3: wstest ...........................Bus error***Exception:   0.01 sec

3/3 Test #2: turbojpeg ........................   Passed   16.52 sec

67% tests passed, 1 tests failed out of 3

Total Test time (real) =  16.52 sec

This has been fixed upstream in:

commit 0cf1400c61850065de590d403f6d49e32882fd76
Author: Rolf Eike Beer <eike@sf-mail.de>
Date:   Tue May 28 18:30:46 2019 +0200

    fix crash because of unaligned accesses in hybiReadAndDecode()

I'm attaching the backported patch. Could you include it in the
next upload?

Thanks,
Adrian

--
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz@debian.org
`. `'   Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913

>From 0cf1400c61850065de590d403f6d49e32882fd76 Mon Sep 17 00:00:00 2001
From: Rolf Eike Beer <eike@sf-mail.de>
Date: Tue, 28 May 2019 18:30:46 +0200
Subject: [PATCH] fix crash because of unaligned accesses in
 hybiReadAndDecode()

---
 libvncserver/ws_decode.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/libvncserver/ws_decode.c b/libvncserver/ws_decode.c
index 441ebc7..10c44d1 100644
--- a/libvncserver/ws_decode.c
+++ b/libvncserver/ws_decode.c
@@ -327,7 +327,6 @@ hybiReadAndDecode(ws_ctx_t *wsctx, char *dst, int len, int *sockRet, int nInBuf)
   int bufsize;
   int nextRead;
   unsigned char *data;
-  uint32_t *data32;
 
   /* if data was carried over, copy to start of buffer */
   memcpy(wsctx->writePos, wsctx->carryBuf, wsctx->carrylen);
@@ -383,10 +382,12 @@ hybiReadAndDecode(ws_ctx_t *wsctx, char *dst, int len, int *sockRet, int nInBuf)
   /* for a possible base64 decoding, we decode multiples of 4 bytes until
    * the whole frame is received and carry over any remaining bytes in the carry buf*/
   data = (unsigned char *)(wsctx->writePos - toDecode);
-  data32= (uint32_t *)data;
 
   for (i = 0; i < (toDecode >> 2); i++) {
-    data32[i] ^= wsctx->header.mask.u;
+    uint32_t tmp;
+    memcpy(&tmp, data + i * sizeof(tmp), sizeof(tmp));
+    tmp ^= wsctx->header.mask.u;
+    memcpy(data + i * sizeof(tmp), &tmp, sizeof(tmp));
   }
   ws_dbg("mask decoding; i=%d toDecode=%d\n", i, toDecode);
 
-- 
2.25.0.rc0