From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-3621199-1521623815-2-12393070609433108524 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='us-ascii' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: linux-api-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1521623815; b=q0dmATia/tVJw+h3/XcfTXtqdfkGp50qw5k/t++FIBHherZ 9VTXmDDhfsMne1qjAJHEQhfWmV7hfKQx/+ecaVmcFZXj4Mxu9N1byehv/yZAwDSG FDVXJIiMldNgsBZwmZjeYsLTt/0pp0B2yx9p0zWJOtf2nmAe9BM0A6DK6IihLfVY Hj2CeKdqRRc4InI+c2+tYyDA4GOQr55x9FdBwtx0TH3eH0saMsBNdYDSUlGxK52T rRfZog+RFGVXgdjyJssvpe5+C9OzUxoIDWJeS4SewIfNaphNnkMMNtXP9mjlttmu E9lt0XMEFiC8SR6jqnrobFFMV6W+KDdH/qeWVXA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=date:from:to:cc:subject:message-id :references:mime-version:content-type:in-reply-to:sender :list-id; s=arctest; t=1521623815; bh=6osunecmNyY3qqjaZK7cLc2Iyd bpaAlC0ejnHKQLAUM=; b=JgnQsYMIehTtWSeSpeqJmz0v3Qs5YbqO7kX/vjXSC9 cPGuSCMe4XchzX84vZhDfdAVwjksBzyDd9nEMu5rbo+YoN4OkZegBtZmVLYATQCH 6PaICoL781XHwBZ9Y4OMbfJsQ5TrFEwHBywGRmFBnLGLN0nsUPZUCLJRhnffmWkY Xc6mWD19U9xbwUh2QIo7cj7jCTRevPgObR2rbF5RK0skuCcjELiq0gAbPAF6U6dV +kfLNIvC9BHorcVsyYCXxA1hNvToKJFmIiCAaLtJQ4nAtomcxCNO5SEJTiFkuc9f p/DO9hsBMrj7dKD2aIBYIJWgDOkvJbHYQ2EYWdGdmceQ== ARC-Authentication-Results: i=1; mx5.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-api-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx5.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-api-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751477AbeCUJQv (ORCPT ); Wed, 21 Mar 2018 05:16:51 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:35938 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751405AbeCUJQu (ORCPT ); Wed, 21 Mar 2018 05:16:50 -0400 Date: Wed, 21 Mar 2018 10:16:48 +0100 From: Greg KH To: Christoph Hellwig Cc: viro@zeniv.linux.org.uk, Avi Kivity , linux-aio@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 4/9] aio: sanitize ki_list handling Message-ID: <20180321091648.GL14085@kroah.com> References: <20180321073232.13366-1-hch@lst.de> <20180321073232.13366-5-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180321073232.13366-5-hch@lst.de> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-api-owner@vger.kernel.org X-Mailing-List: linux-api@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Wed, Mar 21, 2018 at 08:32:27AM +0100, Christoph Hellwig wrote: > Instead of handcoded non-null checks always initialize ki_list to an > empty list and use list_empty / list_empty_careful on it. While we're > at it also error out on a double call to kiocb_set_cancel_fn instead > of ignoring it. > > Signed-off-by: Christoph Hellwig > Acked-by: Jeff Moyer > Reviewed-by: Darrick J. Wong > --- > fs/aio.c | 13 ++++++------- > 1 file changed, 6 insertions(+), 7 deletions(-) > > diff --git a/fs/aio.c b/fs/aio.c > index 6295fc00f104..c32c315f05b5 100644 > --- a/fs/aio.c > +++ b/fs/aio.c > @@ -555,13 +555,12 @@ void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel) > struct kioctx *ctx = req->ki_ctx; > unsigned long flags; > > - spin_lock_irqsave(&ctx->ctx_lock, flags); > - > - if (!req->ki_list.next) > - list_add(&req->ki_list, &ctx->active_reqs); > + if (WARN_ON_ONCE(!list_empty(&req->ki_list))) > + return; Will be fun to see if the syzkaller code ends up tripping on this one, their use of panic-on-warn always is "interesting"... Reviewed-by: Greg Kroah-Hartman > > + spin_lock_irqsave(&ctx->ctx_lock, flags); > + list_add_tail(&req->ki_list, &ctx->active_reqs); > req->ki_cancel = cancel; > - > spin_unlock_irqrestore(&ctx->ctx_lock, flags); > } > EXPORT_SYMBOL(kiocb_set_cancel_fn); > @@ -1034,7 +1033,7 @@ static inline struct aio_kiocb *aio_get_req(struct kioctx *ctx) > goto out_put; > > percpu_ref_get(&ctx->reqs); > - > + INIT_LIST_HEAD(&req->ki_list); > req->ki_ctx = ctx; > return req; > out_put: > @@ -1080,7 +1079,7 @@ static void aio_complete(struct aio_kiocb *iocb, long res, long res2) > unsigned tail, pos, head; > unsigned long flags; > > - if (iocb->ki_list.next) { > + if (!list_empty_careful(iocb->ki_list.next)) { > unsigned long flags; > > spin_lock_irqsave(&ctx->ctx_lock, flags); > -- > 2.14.2 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-api" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html