From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 211B93B19CF; Sat, 17 Oct 2026 16:46:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792255618; cv=none; b=eo8aCw7hEye4BMfNJbPCXgLRmIROPbnQi8DjiBW/nuqynhQCBJPkFLJ97A13ozPYC8w5t/JnCxJv2wHWCz5fj/OXiNXXR75kLZLGNeDgWGoBm1Ogq4axsU50fi67xIBtrS5kUUl4KkOZu74hZA4Iw351XPx4itQ8xdZcmH7JZVc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792255618; c=relaxed/simple; bh=fN5E5Q68EjaZKRyrB8imCcRHA0KA4IC/Y7ooMBgOLOw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KM/jaK6oXvURvkNpcJG5q7Ro/0Y/3JfE/GzOOrZeWrIJHgcnDsmdlKOnBogdgOklvAAqOnFiwiT2KkPP1V1sjoSA38OBvpbNjkeBf+sLWGEIroTdQTSS6yVwlp7sbl9SNO5xBeqOYC/3vMh1FWfEO0+oMoc+XHDsbCyvpZuqKMo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=yksBMOAY; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="yksBMOAY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7774B1F000C4; Sat, 17 Oct 2026 16:46:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792255617; bh=A1hMODZje1c+G/ZsxHxzijzTiMmZJCnIz0YbayBGhIk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=yksBMOAYUcMxwBFml4Jy/+BPowTFKph3ui9JlHrofkQFwy9DUoYSxLr+fYBUyymqw Oxvg/7MUTH3XydOK6jjDf5I2C1uL+zB0O++6GGT/D/Ogu/GhqEIR4xtrgzWN32eJcw LDTBVt0psh1ZsITIAAoED5fJUxhfMosy8h6r8hSQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Anthony Doeraene , Kuniyuki Iwashima , Paolo Abeni , Sasha Levin Subject: [PATCH 6.12 833/869] mpls: Set rt->rt_nhn just before returning from mpls_nh_build_multi(). Date: Sat, 17 Oct 2026 18:01:14 +0200 Message-ID: <20261017160058.234979957@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261017160036.979869304@linuxfoundation.org> References: <20261017160036.979869304@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kuniyuki Iwashima [ Upstream commit 3671f0419d90b98a02f313830595ab958c8b2025 ] Commit f0914b8436c5 ("mpls: Hold dev refcnt for mpls_nh.") added change_nexthops() loop to call netdev_put() for the nexthop devices before freeing mpls_route. Then, mpls_nh_build_multi() was also changed to avoid iterating uninitialised nexthops in mpls_rt_free_rcu(). However, setting rt->rt_nhn to 0 at the entry of mpls_nh_build_multi() makes the following change_nexthops() no-op. Let's set rt->rt_nhn just before returning from mpls_nh_build_multi(). Fixes: f0914b8436c5 ("mpls: Hold dev refcnt for mpls_nh.") Reported-by: Anthony Doeraene Closes: https://lore.kernel.org/netdev/036a0c95-f5d4-46ab-88e7-1eab567d7a84@uclouvain.be/ Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260716170609.804629-1-kuniyu@google.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/mpls/af_mpls.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c index 5c293fa655d0d..70035b1a52c48 100644 --- a/net/mpls/af_mpls.c +++ b/net/mpls/af_mpls.c @@ -929,8 +929,7 @@ static int mpls_nh_build_multi(struct mpls_route_config *cfg, struct nlattr *nla_via, *nla_newdst; int remaining = cfg->rc_mp_len; int err = 0; - - rt->rt_nhn = 0; + u8 nhs = 0; change_nexthops(rt) { int attrlen; @@ -966,12 +965,15 @@ static int mpls_nh_build_multi(struct mpls_route_config *cfg, rt->rt_nhn_alive--; rtnh = rtnh_next(rtnh, &remaining); - rt->rt_nhn++; + nhs++; } endfor_nexthops(rt); + rt->rt_nhn = nhs; + return 0; errout: + rt->rt_nhn = nhs; return err; } -- 2.53.0