From nobody Sat Oct 4 11:11:58 2025 Received: from mail-pl1-f171.google.com (mail-pl1-f171.google.com [209.85.214.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 57B52271450; Mon, 18 Aug 2025 15:40:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.171 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755531638; cv=none; b=Rzj42LTD4oHoojIhynSp6g3/sHOHkvl1MCxkP3GuJcQpEMbVLd1sNHh8SrnIT+HHGCmqAhOkMwE1ZM9zIQx3QMOhHks0FqxdKe9SR4NGwl/DefT1b57NZgVSukJbXSXouIQjTg65VmTCrWO7pCZXW239deCs/RIaIYF7sWNWStM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755531638; c=relaxed/simple; bh=I1peXe3qUgkdzuAIkR3hXhA4fkcFMtLuLZeroJqdEKg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SYiUKMne89aUqu6EwkOxfKHMywENgxNzSX0EthwgXvI7pYA8Mw8WMqJGF2ZPVPG4JE1vm0u1wRlHa5z7plMvJpR2S56T054YHKgI+5twSibheT9K0FOT4lpWMU0iert/vYqJvaOrbxC71/7bysNxUfYyILwM8e4Fi+1wjpYYWqU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fomichev.me; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.214.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fomichev.me Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-pl1-f171.google.com with SMTP id d9443c01a7336-24458195495so26646585ad.2; Mon, 18 Aug 2025 08:40:36 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1755531635; x=1756136435; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=NChDRszGwZKbjvVPRDVNu5XZAg/1N+wVz9IydPSYRlA=; b=nZxi7d+Ma9t2z0EkGn2+HtO1fI03Y1wR/0+11DTaTAUJ60062PYeXnAHH7juKa1lAp gIqNaXa4CzKrkxIGsLWdKtJXkAf64++HgA9oun1iAZgB9ZpPtlhgPTJJh6XX2AP0w+Zq PXOwUFIlYVW8NY+q1/OFx5sUussIjf7aHa1HrPb6vTmNUrgoDc+n8jX0NAuhS2eLAhDi JTuXGVRyEs70b17kxgOd2BI4MHTq1XeUrI9Jg6ZFt3srLzYRG3UJ4lKT3VVz+BNc1aXa VwIZH8tNkHU/zHMIisS04Pw3o+5EXxzQUeFJVGzHntasjnovSZNX9qfZ4eARpEJcpg3w BEtg== X-Forwarded-Encrypted: i=1; AJvYcCUil2I+2zWUoFkyVAPQSHF8fD5030tA0qt2TCcoc3b2msnPjB7hkAOIcK2u/Qwi41CDI0uQ7TSIQ1AozII=@vger.kernel.org, AJvYcCUmHPjkWli/mgD9tKkVoyP4D3kqrr2CA3yI0LBx8uUiSLq3vePzzWxBCzv/yH7JEQqlMp83C37BTQo5Rcp3+d2s@vger.kernel.org X-Gm-Message-State: AOJu0Yz48bkEaG84ozRK9rGgFdVjchIEBds6wtWjHI5lY/mA/QLKGTSb F452fWY5zEfgdy9NB2bZsrrp4lGVrxxLHKcj7ejO6JfdAKSE3wWQmPGgdEB/ X-Gm-Gg: ASbGnctoqQYQHI72NKJILANLLbiOcqB2iuSUVQw26WJ40Om2OiP5Fc3359A1igVe3ND 8rLY1PLNMurFL2HOjV3khITBDccvlaNpwBKk8wP8nwpr0tgnxgfmhVGn8xGFXmcl/XUMulYQrm8 aPyh9EIg+cH7ZaMMrU2zwGu5by1AvRjlAI2UPdyXc1T/QQHtKJ5nS+L9F8qtYqGXmniRVjDYHBm Ci3dZqUMGcMYU5w5u7DosVFdx81GvWP1fq5YdtXRHIpRMAcorb/OCk8lu76kUGpbTTeA+pp7gwr EO30b26Du0e/ILu6qx9rNNsrGvRoTvGRV63HTgMK4yuI9sycHSP+6tPGcdDVOy+PbIWfSM+pkaO 3uldMStdXuJUBfPd+XHbOx1jZV68f3/pp8f8yATX1nfGOCrl0DHkOCYhg6onoBDa5FR/ISw== X-Google-Smtp-Source: AGHT+IEESYdvHRoTRRGZrgyh2K1XOh5rovsTZVhdWVRfTeUiYce7Ghr02VcC+TxaQGwyNNdk27cEjw== X-Received: by 2002:a17:902:e848:b0:240:86b2:aecf with SMTP id d9443c01a7336-24478e11024mr143045015ad.12.1755531635368; Mon, 18 Aug 2025 08:40:35 -0700 (PDT) Received: from localhost (c-73-158-218-242.hsd1.ca.comcast.net. [73.158.218.242]) by smtp.gmail.com with UTF8SMTPSA id d9443c01a7336-2446caa3e5bsm84101975ad.33.2025.08.18.08.40.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Aug 2025 08:40:35 -0700 (PDT) From: Stanislav Fomichev To: netdev@vger.kernel.org Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, ayush.sawal@chelsio.com, andrew+netdev@lunn.ch, gregkh@linuxfoundation.org, horms@kernel.org, dsahern@kernel.org, pablo@netfilter.org, kadlec@netfilter.org, fw@strlen.de, steffen.klassert@secunet.com, sdf@fomichev.me, mhal@rbox.co, abhishektamboli9@gmail.com, linux-kernel@vger.kernel.org, linux-staging@lists.linux.dev, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, herbert@gondor.apana.org.au Subject: [PATCH net-next v2 2/7] xfrm: Switch to skb_dstref_steal to clear dst_entry Date: Mon, 18 Aug 2025 08:40:27 -0700 Message-ID: <20250818154032.3173645-3-sdf@fomichev.me> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250818154032.3173645-1-sdf@fomichev.me> References: <20250818154032.3173645-1-sdf@fomichev.me> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Going forward skb_dst_set will assert that skb dst_entry is empty during skb_dst_set. skb_dstref_steal is added to reset existing entry without doing refcnt. Switch to skb_dstref_steal in __xfrm_route_forward and add a comment on why it's safe to skip skb_dstref_restore. Signed-off-by: Stanislav Fomichev --- net/xfrm/xfrm_policy.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index c5035a9bc3bb..7111184eef59 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -3881,12 +3881,18 @@ int __xfrm_route_forward(struct sk_buff *skb, unsig= ned short family) } =20 skb_dst_force(skb); - if (!skb_dst(skb)) { + dst =3D skb_dst(skb); + if (!dst) { XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR); return 0; } =20 - dst =3D xfrm_lookup(net, skb_dst(skb), &fl, NULL, XFRM_LOOKUP_QUEUE); + /* ignore return value from skb_dstref_steal, xfrm_lookup takes + * care of dropping the refcnt if needed. + */ + skb_dstref_steal(skb); + + dst =3D xfrm_lookup(net, dst, &fl, NULL, XFRM_LOOKUP_QUEUE); if (IS_ERR(dst)) { res =3D 0; dst =3D NULL; --=20 2.50.1