From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E4E1C433EF for ; Mon, 13 Jun 2022 14:45:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1386437AbiFMOpM (ORCPT ); Mon, 13 Jun 2022 10:45:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57512 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1385642AbiFMOni (ORCPT ); Mon, 13 Jun 2022 10:43:38 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A00B6B2E8A; Mon, 13 Jun 2022 04:50:51 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 7782FB80EE6; Mon, 13 Jun 2022 11:50:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C871CC341C6; Mon, 13 Jun 2022 11:50:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655121045; bh=O1BECb1BwhYEIW1CUebpdzDbEJQLtGkgaLnnWW6lRNQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m86mfXN9srmtNV2v94lh/z1MWclq3obJTDDr4PtXMPp/9NLceiziPR8uJ1KGpyVU4 95kk+v2+FgnAMwQL4ITLei0/QRETZ9WRwaL5ROpAKnakJCxcNNHu1z3tGyCuQqnk27 WcaI/h+TywEMyxoCCPn2vBIfO2WpExHbDFzh/uhk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xie Yongji , Fam Zheng , "Michael S. Tsirkin" , Jason Wang , Sasha Levin Subject: [PATCH 5.17 252/298] vringh: Fix loop descriptors check in the indirect cases Date: Mon, 13 Jun 2022 12:12:26 +0200 Message-Id: <20220613094932.724487421@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220613094924.913340374@linuxfoundation.org> References: <20220613094924.913340374@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Xie Yongji [ Upstream commit dbd29e0752286af74243cf891accf472b2f3edd8 ] We should use size of descriptor chain to test loop condition in the indirect case. And another statistical count is also introduced for indirect descriptors to avoid conflict with the statistical count of direct descriptors. Fixes: f87d0fbb5798 ("vringh: host-side implementation of virtio rings.") Signed-off-by: Xie Yongji Signed-off-by: Fam Zheng Message-Id: <20220505100910.137-1-xieyongji@bytedance.com> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Signed-off-by: Sasha Levin --- drivers/vhost/vringh.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c index 14e2043d7685..eab55accf381 100644 --- a/drivers/vhost/vringh.c +++ b/drivers/vhost/vringh.c @@ -292,7 +292,7 @@ __vringh_iov(struct vringh *vrh, u16 i, int (*copy)(const struct vringh *vrh, void *dst, const void *src, size_t len)) { - int err, count = 0, up_next, desc_max; + int err, count = 0, indirect_count = 0, up_next, desc_max; struct vring_desc desc, *descs; struct vringh_range range = { -1ULL, 0 }, slowrange; bool slow = false; @@ -349,7 +349,12 @@ __vringh_iov(struct vringh *vrh, u16 i, continue; } - if (count++ == vrh->vring.num) { + if (up_next == -1) + count++; + else + indirect_count++; + + if (count > vrh->vring.num || indirect_count > desc_max) { vringh_bad("Descriptor loop in %p", descs); err = -ELOOP; goto fail; @@ -411,6 +416,7 @@ __vringh_iov(struct vringh *vrh, u16 i, i = return_from_indirect(vrh, &up_next, &descs, &desc_max); slow = false; + indirect_count = 0; } else break; } -- 2.35.1