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 E4E96C00A8F for ; Mon, 23 Oct 2023 11:34:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233954AbjJWLem (ORCPT ); Mon, 23 Oct 2023 07:34:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33218 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234013AbjJWLel (ORCPT ); Mon, 23 Oct 2023 07:34:41 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F014DE8 for ; Mon, 23 Oct 2023 04:34:39 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3DEEDC433C8; Mon, 23 Oct 2023 11:34:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1698060879; bh=mUPe7NlIlOkZdHDrwzs/S3mQAcVWvUhUKjK3iD4U7f8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gCb8q9tP2g4uQPqENrgGDmvjpRLpE11wnDo1ItZGTgCNW/A5qPJDptV70m6/NB/lw om+TaFmJuxT14l+S3c939kjbtL8uddZRwaa/+GzcgDMIkLQu0+P+sS9dUQPjBuULvY JMcOKQtaOcej4MGTClJSQx4+tsVRt2/WnVaO7M+w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhang Changzhong , Xin Long , Steffen Klassert , Sasha Levin Subject: [PATCH 5.4 123/123] xfrm6: fix inet6_dev refcount underflow problem Date: Mon, 23 Oct 2023 12:58:01 +0200 Message-ID: <20231023104821.923823871@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231023104817.691299567@linuxfoundation.org> References: <20231023104817.691299567@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zhang Changzhong [ Upstream commit cc9b364bb1d58d3dae270c7a931a8cc717dc2b3b ] There are race conditions that may lead to inet6_dev refcount underflow in xfrm6_dst_destroy() and rt6_uncached_list_flush_dev(). One of the refcount underflow bugs is shown below: (cpu 1) | (cpu 2) xfrm6_dst_destroy() | ... | in6_dev_put() | | rt6_uncached_list_flush_dev() ... | ... | in6_dev_put() rt6_uncached_list_del() | ... ... | xfrm6_dst_destroy() calls rt6_uncached_list_del() after in6_dev_put(), so rt6_uncached_list_flush_dev() has a chance to call in6_dev_put() again for the same inet6_dev. Fix it by moving in6_dev_put() after rt6_uncached_list_del() in xfrm6_dst_destroy(). Fixes: 510c321b5571 ("xfrm: reuse uncached_list to track xdsts") Signed-off-by: Zhang Changzhong Reviewed-by: Xin Long Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/ipv6/xfrm6_policy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/ipv6/xfrm6_policy.c +++ b/net/ipv6/xfrm6_policy.c @@ -120,11 +120,11 @@ static void xfrm6_dst_destroy(struct dst { struct xfrm_dst *xdst = (struct xfrm_dst *)dst; - if (likely(xdst->u.rt6.rt6i_idev)) - in6_dev_put(xdst->u.rt6.rt6i_idev); dst_destroy_metrics_generic(dst); if (xdst->u.rt6.rt6i_uncached_list) rt6_uncached_list_del(&xdst->u.rt6); + if (likely(xdst->u.rt6.rt6i_idev)) + in6_dev_put(xdst->u.rt6.rt6i_idev); xfrm_dst_destroy(xdst); }