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 97C44C004C0 for ; Mon, 23 Oct 2023 11:42:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234307AbjJWLmU (ORCPT ); Mon, 23 Oct 2023 07:42:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234316AbjJWLmS (ORCPT ); Mon, 23 Oct 2023 07:42:18 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F129F10F6 for ; Mon, 23 Oct 2023 04:41:56 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 32DC5C433D9; Mon, 23 Oct 2023 11:41:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1698061316; bh=cDMc2o9eofNcoIErJEvzrHBQefibJo8DUS55DHV0kKg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jxpHW+xvrgqXpCly481WyeGwRPq8yTmsvYnfNFwnpEoGySEV2IWG7O1sQL8tjCHTJ w80re/czzzjnHruyhvtKbUBviErvEI1HJ/ZsWF+mS7KKJ6HUAyCXTVxWJSYkBQ9KpV xT7KbuUV7sm+s+JBekV3D7X4Ja66qyN9D8OHpMqI= 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 5.15 137/137] xfrm6: fix inet6_dev refcount underflow problem Date: Mon, 23 Oct 2023 12:58:14 +0200 Message-ID: <20231023104825.293800344@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231023104820.849461819@linuxfoundation.org> References: <20231023104820.849461819@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 5.15-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); }