On Friday, July 31, 2020, Greg Kroah-Hartman wrote: > On Fri, Jul 31, 2020 at 07:33:06AM +0200, Greg Kroah-Hartman wrote: > > On Fri, Jul 31, 2020 at 07:53:01AM +0300, Leon Romanovsky wrote: > > > On Thu, Jul 30, 2020 at 03:20:26PM -0400, Peilin Ye wrote: > > > > rds_notify_queue_get() is potentially copying uninitialized kernel > stack > > > > memory to userspace since the compiler may leave a 4-byte hole at > the end > > > > of `cmsg`. > > > > > > > > In 2016 we tried to fix this issue by doing `= { 0 };` on `cmsg`, > which > > > > unfortunately does not always initialize that 4-byte hole. Fix it by > using > > > > memset() instead. > > > > > > Of course, this is the difference between "{ 0 }" and "{}" > initializations. > > > > Really? Neither will handle structures with holes in it, try it and > > see. {} is a GCC extension, but I never thought it works differently. > > And if true, where in the C spec does it say that? > > thanks, > > greg k-h > -- With Best Regards, Andy Shevchenko