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 0D594CCA47C for ; Mon, 13 Jun 2022 12:20:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352665AbiFMMUk (ORCPT ); Mon, 13 Jun 2022 08:20:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53716 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358990AbiFMMTk (ORCPT ); Mon, 13 Jun 2022 08:19:40 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0DA8E56FAE; Mon, 13 Jun 2022 04:03:10 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 1681C614A8; Mon, 13 Jun 2022 11:03:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 245DDC34114; Mon, 13 Jun 2022 11:03:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655118189; bh=Aq5IGVpLu/dgzqu2jUzOzzSrBhplJ3oD1IJZ1ojJFc8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vJwSb62q7r9RMgltp6wgENga5f24aAzNstdzGl6qD17qI4U+N2dwguqfEJ6TAcwzk c1leEEx7hVzGA/0nuBD/RX060W0iH4qMdKVIXUGN6OpmzZIOod2daPvxbjaye+oetg JKv8/Zw1zfNBgv5KO8NLUjqvYtwr6gQoJWAMOwXo= 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 4.19 274/287] vringh: Fix loop descriptors check in the indirect cases Date: Mon, 13 Jun 2022 12:11:38 +0200 Message-Id: <20220613094932.306134383@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220613094923.832156175@linuxfoundation.org> References: <20220613094923.832156175@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 97aa9b87e572..6b2efff1c297 100644 --- a/drivers/vhost/vringh.c +++ b/drivers/vhost/vringh.c @@ -263,7 +263,7 @@ __vringh_iov(struct vringh *vrh, u16 i, gfp_t gfp, int (*copy)(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; @@ -320,7 +320,12 @@ __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; @@ -382,6 +387,7 @@ __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