[PATCH libXi] Allocate enough memory for raw events + extra data.

[Peter Hutterer]

On Mon, May 02, 2011 at 09:05:21PM -0700, Jeremy Huddleston wrote:
> Woot.  That takes care of:
> 
> http://people.freedesktop.org/~jeremyhu/analyzer/yuffie/20110429-1617/libXi/report-kzyPla.html#EndPath
> 
> It looks like there are others you might want to do at the same time:
> http://people.freedesktop.org/~jeremyhu/analyzer/yuffie/20110429-1617/libXi/

re "Idempotent operation"
I'm staring hard at those but don't really see the issue.
SetReqLen(req, foo, foo); is valid and for any foo that is non-zero
shouldn't have the effect of "Assigned value is always the same as the
existing value". SetReqLen essentially does req->length += foo.

http://people.freedesktop.org/~jeremyhu/analyzer/yuffie/20110429-1617/libXi/report-yDDyYj.html#EndPath
"undefined allocation of 0 bytes" would be a server bug afaict

http://people.freedesktop.org/~jeremyhu/analyzer/yuffie/20110429-1617/libXi/report-n6GgtE.html#EndPath
don't want to change this one, it's there for symmetry.

Cheers,
  Peter

> On May 2, 2011, at 8:50 PM, Peter Hutterer wrote:
> 
> > Necessary space was calculated, but not actually used to allocate memory. As
> > a result, valuator data would overwrite the allocated memory.
> > 
> > ==4166== Invalid write of size 1
> > ==4166==    at 0x4C29F04: memcpy (mc_replace_strmem.c:497)
> > ==4166==    by 0x8F39180: ??? (in /usr/lib/libXi.so.6.1.0)
> > ==4166==    by 0x7433D48: _XCopyEventCookie (in /usr/lib/libX11.so.6.3.0)
> > ==4166==    by 0x7425166: XPeekEvent (in /usr/lib/libX11.so.6.3.0)
> > ==4166==    by 0x49C3E3: process_key (x11_be.c:1065)
> > ==4166==    by 0x49EA5C: event_key_release (x11_be.c:2201)
> > ==4166==    by 0x49DD6E: x11_be_process_events (x11_be.c:1892)
> > ==4166==    by 0x4A38F4: x11_be_main_loop (x11_be.c:4353)
> > ==4166==    by 0x4A39E1: x11_be_thread_main (x11_be.c:4385)
> > ==4166==    by 0x87549C9: start_thread (pthread_create.c:300)
> > ==4166==    by 0x8A516FC: clone (clone.S:112)
> > ==4166==  Address 0x168afe80 is 0 bytes after a block of size 96 alloc'd
> > ==4166==    at 0x4C284A8: malloc (vg_replace_malloc.c:236)
> > ==4166==    by 0x8F390BD: ??? (in /usr/lib/libXi.so.6.1.0)
> > ==4166==    by 0x7433D48: _XCopyEventCookie (in /usr/lib/libX11.so.6.3.0)
> > ==4166==    by 0x7425166: XPeekEvent (in /usr/lib/libX11.so.6.3.0)
> > ==4166==    by 0x49C3E3: process_key (x11_be.c:1065)
> > ==4166==    by 0x49EA5C: event_key_release (x11_be.c:2201)
> > ==4166==    by 0x49DD6E: x11_be_process_events (x11_be.c:1892)
> > ==4166==    by 0x4A38F4: x11_be_main_loop (x11_be.c:4353)
> > ==4166==    by 0x4A39E1: x11_be_thread_main (x11_be.c:4385)
> > ==4166==    by 0x87549C9: start_thread (pthread_create.c:300)
> > 
> > Reported-by: Roger Cruz <roger.cruz at virtualcomputer.com>
> > Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
> > ---
> > Sorry, was away for a number of days and only got to this now. You're right,
> > it's a bug, copy/paste I guess.
> > 
> > src/XExtInt.c |    2 +-
> > 1 files changed, 1 insertions(+), 1 deletions(-)
> > 
> > diff --git a/src/XExtInt.c b/src/XExtInt.c
> > index d1451cc..134ccc6 100644
> > --- a/src/XExtInt.c
> > +++ b/src/XExtInt.c
> > @@ -1259,7 +1259,7 @@ copyRawEvent(XGenericEventCookie *cookie_in,
> >     len = sizeof(XIRawEvent) + in->valuators.mask_len;
> >     len += bits * sizeof(double) * 2;
> > 
> > -    ptr = cookie_out->data = malloc(sizeof(XIRawEvent));
> > +    ptr = cookie_out->data = malloc(len);
> >     if (!ptr)
> >         return False;
> > 
> > -- 
> > 1.7.4.4