[X2Go-Commits] [nx-libs] 08/30: os/io.c: fix unitialised bytes

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x2go pushed a commit to branch 3.6.x
in repository nx-libs.

commit e5975a70e8e03e58f102e8e238143d22cd4d1ed5
Author: Ulrich Sibiller <uli42 at gmx.de>
Date:   Thu Jun 21 23:05:05 2018 +0200

    os/io.c: fix unitialised bytes
    
    ... by implementing some kind of recalloc (mix of realloc and calloc).
    
    Fixes this valgrind finding:
    
    ==7061== Syscall param writev(vector[...]) points to uninitialised byte(s)
    ==7061==    at 0x781EFE0: __writev_nocancel (syscall-template.S:84)
    ==7061==    by 0x488974: _XSERVTransSocketWritev (Xtranssock.c:2914)
    ==7061==    by 0x47DBD3: FlushClient (io.c:1080)
    ==7061==    by 0x47DBD3: FlushAllOutput.part.0 (io.c:817)
    ==7061==    by 0x477304: WaitForSomething (WaitFor.c:246)
    ==7061==    by 0x434369: Dispatch (NXdispatch.c:360)
    ==7061==    by 0x40EB92: main (main.c:353)
    ==7061==  Address 0x102106f3 is 50,211 bytes inside a block of size 54,308 alloc'd
    ==7061==    at 0x4C2FD5F: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
    ==7061==    by 0x47F08F: FlushClient (io.c:1123)
    ==7061==    by 0x47F307: WriteToClient (io.c:991)
    ==7061==    by 0x42903C: doListFontsAndAliases (NXdixfonts.c:660)
    ==7061==    by 0x42B7D6: ListFonts (NXdixfonts.c:735)
    ==7061==    by 0x433A6D: ProcListFonts (NXdispatch.c:989)
    ==7061==    by 0x4344A5: Dispatch (NXdispatch.c:482)
    ==7061==    by 0x40EB92: main (main.c:353)
    ==7061==  Uninitialised value was created by a heap allocation
    ==7061==    at 0x4C2FD5F: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
    ==7061==    by 0x47F08F: FlushClient (io.c:1123)
    ==7061==    by 0x47F307: WriteToClient (io.c:991)
    ==7061==    by 0x42903C: doListFontsAndAliases (NXdixfonts.c:660)
    ==7061==    by 0x42B7D6: ListFonts (NXdixfonts.c:735)
    ==7061==    by 0x433A6D: ProcListFonts (NXdispatch.c:989)
    ==7061==    by 0x4344A5: Dispatch (NXdispatch.c:482)
    ==7061==    by 0x40EB92: main (main.c:353)
    ==7061==
---
 nx-X11/programs/Xserver/os/io.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/nx-X11/programs/Xserver/os/io.c b/nx-X11/programs/Xserver/os/io.c
index 0739943..6eeee34 100644
--- a/nx-X11/programs/Xserver/os/io.c
+++ b/nx-X11/programs/Xserver/os/io.c
@@ -1120,7 +1120,12 @@ FlushClient(ClientPtr who, OsCommPtr oc, const void *__extraBuf, int extraCount)
 		unsigned char *obuf = NULL;
 
 		if (notWritten + BUFSIZE <= INT_MAX) {
-		    obuf = realloc(oco->buf, notWritten + BUFSIZE);
+		    obuf = calloc(1, notWritten + BUFSIZE);
+		    if (obuf)
+		    {
+			memmove(obuf, oco->buf, oco->size);
+			free(oco->buf);
+		    }
 		}
 		if (!obuf)
 		{

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