From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.secunet.com (mx1.secunet.com [62.96.220.36]) (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 501443CE4A8 for ; Wed, 27 May 2026 08:42:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.96.220.36 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779871334; cv=none; b=U8xyeahMt9tUphCHcD7iBfXREi8R5F/LCCM+NiKwtA+reSOoeU+UlGYJEXSQL0fbrvHDFq1hdyr5dSEMPfRdTc8oR3zsSt3I7voN4v1VkhlT/mViXUiCu1v13qQCFUulKw4V2D1CVNfhR5uXr9ulH1ktTgOPKey1LXyorbncrLQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779871334; c=relaxed/simple; bh=Tn9Vh6lk4TPwk2plIigFtlOBhE/inXrsEOxnBBemws0=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Xmgb0o3CPJU1xkfNlLHH2XsjcgD0iSzNcICfz8oi14mqZ98AhRoXGgJh2n3xONv7iqCq5dqbSNblqB4pa8ToS78XURBo6n0uELEojAicLSVcXvdOa+rc6rcswWMElAM2dqQXbRQFNTv5yMTDxeknbC5Gu9nqwuw13Xsw3t9wtPg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=secunet.com; spf=pass smtp.mailfrom=secunet.com; dkim=pass (2048-bit key) header.d=secunet.com header.i=@secunet.com header.b=kX1hJaLY; arc=none smtp.client-ip=62.96.220.36 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=secunet.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=secunet.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=secunet.com header.i=@secunet.com header.b="kX1hJaLY" Received: from localhost (localhost [127.0.0.1]) by mx1.secunet.com (Postfix) with ESMTP id 80BA020743; Wed, 27 May 2026 10:42:05 +0200 (CEST) X-Virus-Scanned: by secunet Received: from mx1.secunet.com ([127.0.0.1]) by localhost (mx1.secunet.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id V8FspgDEtfJq; Wed, 27 May 2026 10:42:04 +0200 (CEST) Received: from EXCH-01.secunet.de (rl1.secunet.de [10.32.0.231]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.secunet.com (Postfix) with ESMTPS id 9D3C020520; Wed, 27 May 2026 10:42:04 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.secunet.com 9D3C020520 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=secunet.com; s=202301; t=1779871324; bh=KB0th1dYDKJrFsi5EBh10y198H1Hzqb/INYAyGXviaQ=; h=From:To:CC:Subject:Date:In-Reply-To:References:From; b=kX1hJaLY+Wl0FCZCI6mdBT9TJymyGiK2X/LEreCzWURTw7ahsjPuKvAMj05yTekh8 JXrfMdqw9fP2SA9sda2L7KDXg/2zNg0X+60muNGcXH9kfybUZ+fnpqokn7U0CrCAdA nO50nZ2MObn86zEkjh7hKU5OE7bhdFd9JiebpAh9y8gEMQjCi1jzaQFB1IAnvDJG22 yoqs1IIIUnOSWNsMBHtfmuVILraEq4tlsogSbfu3nGeePqvzgeeejj8yM8oZbo40NK 7fpOhvarEzN+3JwZ+eCp4iOx9vwKn8+eGFlRzunttMo1b5cy/FkycaOpjzPP47vIYG mQkKgrwbuvRew== Received: from secunet.com (10.182.7.193) by EXCH-01.secunet.de (10.32.0.171) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.37; Wed, 27 May 2026 10:42:04 +0200 Received: (nullmailer pid 3494000 invoked by uid 1000); Wed, 27 May 2026 08:42:01 -0000 From: Steffen Klassert To: David Miller , Jakub Kicinski CC: Herbert Xu , Steffen Klassert , Subject: [PATCH 5/9] esp: fix page frag reference leak on skb_to_sgvec failure Date: Wed, 27 May 2026 10:41:23 +0200 Message-ID: <20260527084148.3489759-6-steffen.klassert@secunet.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260527084148.3489759-1-steffen.klassert@secunet.com> References: <20260527084148.3489759-1-steffen.klassert@secunet.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: EXCH-03.secunet.de (10.32.0.183) To EXCH-01.secunet.de (10.32.0.171) From: e521588 In esp_output_tail(), when esp->inplace is false, the old skb page frags are replaced with a new page from the xfrm page_frag cache. The source scatterlist (sg) is built from the old frags before the replacement, and esp_ssg_unref() is responsible for releasing the old page references after the crypto operation completes. However, if the second skb_to_sgvec() call (which builds the destination scatterlist from the new page) fails, the code jumps to error_free which only calls kfree(tmp). The old page frag references captured in the source scatterlist are never released: 1. sg[] is built from old frags via skb_to_sgvec() (no extra get_page) 2. nr_frags is set to 1 and frag[0] is replaced with the new page 3. Second skb_to_sgvec() fails -> goto error_free 4. kfree(tmp) frees the sg[] memory but old frags are not unref'd 5. kfree_skb() only releases frag[0] (the new page), not the old ones Fix this by adding a bool parameter to esp_ssg_unref() that, when true, unconditionally unrefs the source scatterlist frags without checking req->src and req->dst, since those fields are not yet initialized by aead_request_set_crypt() at the point of the error. Existing callers pass false to preserve the original behavior. The same issue exists in both esp4 and esp6 as the code is identical. Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible") Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible") Signed-off-by: Alessandro Schino <7991aleschino@gmail.com> Signed-off-by: Steffen Klassert --- net/ipv4/esp4.c | 12 +++++++----- net/ipv6/esp6.c | 12 +++++++----- 2 files changed, 14 insertions(+), 10 deletions(-) diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index 6a5febbdbee4..8314d7bddcb7 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -96,7 +96,7 @@ static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead, __alignof__(struct scatterlist)); } -static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb) +static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb, bool already_unref) { struct crypto_aead *aead = x->data; int extralen = 0; @@ -113,7 +113,7 @@ static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb) /* Unref skb_frag_pages in the src scatterlist if necessary. * Skip the first sg which comes from skb->data. */ - if (req->src != req->dst) + if (already_unref || req->src != req->dst) for (sg = sg_next(req->src); sg; sg = sg_next(sg)) skb_page_unref(page_to_netmem(sg_page(sg)), skb->pp_recycle); @@ -220,7 +220,7 @@ static void esp_output_done(void *data, int err) } tmp = ESP_SKB_CB(skb)->tmp; - esp_ssg_unref(x, tmp, skb); + esp_ssg_unref(x, tmp, skb, false); kfree(tmp); if (xo && (xo->flags & XFRM_DEV_RESUME)) { @@ -569,8 +569,10 @@ int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info * err = skb_to_sgvec(skb, dsg, (unsigned char *)esph - skb->data, assoclen + ivlen + esp->clen + alen); - if (unlikely(err < 0)) + if (unlikely(err < 0)) { + esp_ssg_unref(x, tmp, skb, true); goto error_free; + } } if ((x->props.flags & XFRM_STATE_ESN)) @@ -602,7 +604,7 @@ int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info * } if (sg != dsg) - esp_ssg_unref(x, tmp, skb); + esp_ssg_unref(x, tmp, skb, false); if (!err && x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP) err = esp_output_tail_tcp(x, skb); diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c index 9c06c5a1419d..9d0c4957ac62 100644 --- a/net/ipv6/esp6.c +++ b/net/ipv6/esp6.c @@ -113,7 +113,7 @@ static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead, __alignof__(struct scatterlist)); } -static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb) +static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb, bool already_unref) { struct crypto_aead *aead = x->data; int extralen = 0; @@ -130,7 +130,7 @@ static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb) /* Unref skb_frag_pages in the src scatterlist if necessary. * Skip the first sg which comes from skb->data. */ - if (req->src != req->dst) + if (already_unref || req->src != req->dst) for (sg = sg_next(req->src); sg; sg = sg_next(sg)) skb_page_unref(page_to_netmem(sg_page(sg)), skb->pp_recycle); @@ -254,7 +254,7 @@ static void esp_output_done(void *data, int err) } tmp = ESP_SKB_CB(skb)->tmp; - esp_ssg_unref(x, tmp, skb); + esp_ssg_unref(x, tmp, skb, false); kfree(tmp); esp_output_encap_csum(skb); @@ -600,8 +600,10 @@ int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info err = skb_to_sgvec(skb, dsg, (unsigned char *)esph - skb->data, assoclen + ivlen + esp->clen + alen); - if (unlikely(err < 0)) + if (unlikely(err < 0)) { + esp_ssg_unref(x, tmp, skb, true); goto error_free; + } } if ((x->props.flags & XFRM_STATE_ESN)) @@ -634,7 +636,7 @@ int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info } if (sg != dsg) - esp_ssg_unref(x, tmp, skb); + esp_ssg_unref(x, tmp, skb, false); if (!err && x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP) err = esp_output_tail_tcp(x, skb); -- 2.43.0