From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Viro Subject: Re: [PATCH 3/6] aio: refactor read/write iocb setup Date: Fri, 6 Apr 2018 13:28:48 +0100 Message-ID: <20180406122848.GA30522@ZenIV.linux.org.uk> References: <20180328072639.16885-1-hch@lst.de> <20180328072639.16885-4-hch@lst.de> <20180406032146.GV30522@ZenIV.linux.org.uk> <20180406071011.GA21308@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20180406071011.GA21308@lst.de> Sender: owner-linux-aio@kvack.org To: Christoph Hellwig Cc: Avi Kivity , linux-aio@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-api@vger.kernel.org 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. -- To unsubscribe, send a message with 'unsubscribe linux-aio' in the body to majordomo@kvack.org. For more info on Linux AIO, see: http://www.kvack.org/aio/ Don't email: aart@kvack.org