On Fri, Apr 06, 2018 at 09:10:11AM +0200, Christoph Hellwig wrote: > On Fri, Apr 06, 2018 at 04:21:46AM +0100, Al Viro wrote: > > On Wed, Mar 28, 2018 at 09:26:36AM +0200, Christoph Hellwig wrote: > > > + struct inode *inode = file_inode(file); > > > + > > > req->ki_flags |= IOCB_WRITE; > > > file_start_write(file); > > > - ret = aio_ret(req, call_write_iter(file, req, &iter)); > > > + ret = aio_rw_ret(req, call_write_iter(file, req, &iter)); > > > /* > > > - * We release freeze protection in aio_complete(). Fool lockdep > > > - * by telling it the lock got released so that it doesn't > > > - * complain about held lock when we return to userspace. > > > + * We release freeze protection in aio_complete_rw(). Fool > > > + * lockdep by telling it the lock got released so that it > > > + * doesn't complain about held lock when we return to userspace. > > > */ > > > - if (S_ISREG(file_inode(file)->i_mode)) > > > - __sb_writers_release(file_inode(file)->i_sb, SB_FREEZE_WRITE); > > > + if (S_ISREG(inode->i_mode)) > > > > ... and that's another use-after-free, since we might've already done fput() of > > that sucker by that point. > > Indeed. Not in any way new in this patch, this is an existing issue > dating way back that needs to be fixed, which will be rather annoying > without taking an extra reference to the inode or at least sb. New, actually - mainline has get_file()/fput() around the equivalent area.
