Properly handle the return value of XGetWindowProperty by considering if after the loop as well.
Using freed pointer "prop_ret" There were numerous things wrong in how this function interacted with XGetWindowProperty. None of the local variables were initialized and remained that way if the call to XGetWindowProperty returned 1 (not Succeed). That doesn't result in after_ret being initialized in which case if it happens to be 0, the loop was exited. In that case format_ret and nitems_ret were uninitialized and the function might return with success (but with uninitialized pointer in prop_ret) or XcmsFailure. As the buffer enlarging code was called only when XGetWindowProperty failed (returned not Success), after_ret would not have been initialized. It would have been initialized only if the XGetWindowProperty has returned Success earlier, but in that case the code fragment would not have been reached. This patch alters the function to return XcmsFailure if the call to XGetWindowProperty fails. Reviewed-by: Ander Conselvan de Oliveira <ander.conselvan-de-olive...@nokia.com> Reviewed-by: Rami Ylimäki <rami.ylim...@vincit.fi> Signed-off-by: Erkki Seppälä <erkki.sepp...@vincit.fi> --- src/xcms/cmsProp.c | 17 ++++++++++------- 1 files changed, 10 insertions(+), 7 deletions(-) diff --git a/src/xcms/cmsProp.c b/src/xcms/cmsProp.c index 856ae84..2826ee7 100644 --- a/src/xcms/cmsProp.c +++ b/src/xcms/cmsProp.c @@ -121,20 +121,23 @@ _XcmsGetProperty( long len = 6516; unsigned long nitems_ret, after_ret; Atom atom_ret; + int xgwp_ret; - while (XGetWindowProperty (pDpy, w, property, 0, len, False, - XA_INTEGER, &atom_ret, &format_ret, - &nitems_ret, &after_ret, - (unsigned char **)&prop_ret)) { - if (after_ret > 0) { + while (True) { + xgwp_ret = XGetWindowProperty (pDpy, w, property, 0, len, False, + XA_INTEGER, &atom_ret, &format_ret, + &nitems_ret, &after_ret, + (unsigned char **)&prop_ret); + if (xgwp_ret == Success && after_ret > 0) { len += nitems_ret * (format_ret >> 3); XFree (prop_ret); } else { break; } } - if (format_ret == 0 || nitems_ret == 0) { - /* the property does not exist or is of an unexpected type */ + if (xgwp_ret != Success || format_ret == 0 || nitems_ret == 0) { + /* the property does not exist or is of an unexpected type or + getting window property failed */ return(XcmsFailure); } -- 1.7.0.4 _______________________________________________ xorg-devel@lists.x.org: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: http://lists.x.org/mailman/listinfo/xorg-devel