On Thu, 2018-09-13 at 13:13 +0100, Al Viro wrote: > On Thu, Sep 13, 2018 at 01:49:09PM +0200, Johannes Berg wrote: > > From: Johannes Berg <johannes.b...@intel.com> > > > > As reported by Reobert O'Callahan, since Viro's commit to kill > > dev_ifsioc() we attempt to copy too much data in compat mode, > > which may lead to EFAULT when the 32-bit version of struct ifreq > > sits at/near the end of a page boundary, and the next page isn't > > mapped. > > > > Fix this by passing whether or not we're doing a compat call and > > copying the appropriate size in/out, as we did before. This works > > because only the embedded "struct ifmap" has different size, and > > this is only used in SIOCGIFMAP/SIOCSIFMAP which has a different > > handler. All other parts of the union are naturally compatible. > > Might be better to pass explicit size instead of this bool compat...
Yeah, that's a bit better perhaps, I should resend to have the bugzilla link anyway. johannes
