From e5975a70e8e03e58f102e8e238143d22cd4d1ed5 Mon Sep 17 00:00:00 2001 From: Ulrich Sibiller Date: Thu, 21 Jun 2018 23:05:05 +0200 Subject: 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(-) (limited to 'nx-X11/programs/Xserver/os') diff --git a/nx-X11/programs/Xserver/os/io.c b/nx-X11/programs/Xserver/os/io.c index 07399438e..6eeee349a 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) { -- cgit v1.2.3