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 322D238F945; Wed, 20 May 2026 16:32:49 +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=1779294770; cv=none; b=CFuDzvhJkhToGZKrkh4kRgG6WkpAGUkR+NWrFTLj15w4z5DCxS3BTRbn4DOw3bsixXZPsSnx2euGrqsh5FNp829BOgUgdv2GV6H4vfTU/WlGxBFZrNLXdhOgjqy9k0q443/EVhcfAcsswxA30g8eLFr+PtWzS2FlgVwJhAXN62Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779294770; c=relaxed/simple; bh=7F3fMpfWIbaiFYVsGjmc2Wb/QaT8/fOyBPFqeyeyQg8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZB4M64bjKaeJRtg9CEb2/vVw5X8Zuzo/XNOGxd4H4nt3PkwfsBoYOBGIGhmncS4X9Eb8UC/spp3muHphyM7N+Od5mn4i0mPA/d8H08uFx0yH4/ekq5uIrhJBUl9+CaUtUu8OTaIfmT9ozdSURsXuwfR8HYzu5+gznXrtxTqV2z4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Gh1mX8+5; 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="Gh1mX8+5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 96E081F000E9; Wed, 20 May 2026 16:32:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779294769; bh=cZRUH0OvOJOiNOaWlfdwJk6YPMt1Kk3atA8jiZh4OtU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Gh1mX8+52RHRXjZv77uOOnEfQ3nN3s/4lpug2Xj0cU8tyoKtvL8frq+nyodLVJu3r y59PYF+6Fh48RQfMlWN5nP+nWKkzKRZbMBL/G44zXYM7ik8iu00W4Fbhh7gNYk10yH ZHInTdKNJne240Q5dwhTgOBEctXmdxro760PYFRs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Joe Damato , Jakub Kicinski , Sasha Levin Subject: [PATCH 7.0 0163/1146] net: pull headers in qdisc_pkt_len_segs_init() Date: Wed, 20 May 2026 18:06:53 +0200 Message-ID: <20260520162151.982730361@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162148.390695140@linuxfoundation.org> References: <20260520162148.390695140@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 7.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 7fb4c19670110f052c04e1ec1d2b953b9f4f57e4 ] Most ndo_start_xmit() methods expects headers of gso packets to be already in skb->head. net/core/tso.c users are particularly at risk, because tso_build_hdr() does a memcpy(hdr, skb->data, hdr_len); qdisc_pkt_len_segs_init() already does a dissection of gso packets. Use pskb_may_pull() instead of skb_header_pointer() to make sure drivers do not have to reimplement this. Some malicious packets could be fed, detect them so that we can drop them sooner with a new SKB_DROP_REASON_SKB_BAD_GSO drop_reason. Fixes: e876f208af18 ("net: Add a software TSO helper API") Signed-off-by: Eric Dumazet Reviewed-by: Joe Damato Link: https://patch.msgid.link/20260403221540.3297753-3-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- include/net/dropreason-core.h | 3 +++ net/core/dev.c | 51 +++++++++++++++++++++-------------- 2 files changed, 34 insertions(+), 20 deletions(-) diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h index 8e498e8431cbb..880a5ec786cfe 100644 --- a/include/net/dropreason-core.h +++ b/include/net/dropreason-core.h @@ -80,6 +80,7 @@ FN(UNHANDLED_PROTO) \ FN(SKB_CSUM) \ FN(SKB_GSO_SEG) \ + FN(SKB_BAD_GSO) \ FN(SKB_UCOPY_FAULT) \ FN(DEV_HDR) \ FN(DEV_READY) \ @@ -427,6 +428,8 @@ enum skb_drop_reason { SKB_DROP_REASON_SKB_CSUM, /** @SKB_DROP_REASON_SKB_GSO_SEG: gso segmentation error */ SKB_DROP_REASON_SKB_GSO_SEG, + /** @SKB_DROP_REASON_SKB_BAD_GSO: malicious gso packet. */ + SKB_DROP_REASON_SKB_BAD_GSO, /** * @SKB_DROP_REASON_SKB_UCOPY_FAULT: failed to copy data from user space, * e.g., via zerocopy_sg_from_iter() or skb_orphan_frags_rx() diff --git a/net/core/dev.c b/net/core/dev.c index 44a712f777b79..e4fcf09ba2beb 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4103,16 +4103,16 @@ struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *d } EXPORT_SYMBOL_GPL(validate_xmit_skb_list); -static void qdisc_pkt_len_segs_init(struct sk_buff *skb) +static enum skb_drop_reason qdisc_pkt_len_segs_init(struct sk_buff *skb) { struct skb_shared_info *shinfo = skb_shinfo(skb); - unsigned int hdr_len; + unsigned int hdr_len, tlen; u16 gso_segs; qdisc_skb_cb(skb)->pkt_len = skb->len; if (!shinfo->gso_size) { qdisc_skb_cb(skb)->pkt_segs = 1; - return; + return SKB_NOT_DROPPED_YET; } qdisc_skb_cb(skb)->pkt_segs = gso_segs = shinfo->gso_segs; @@ -4120,43 +4120,49 @@ static void qdisc_pkt_len_segs_init(struct sk_buff *skb) /* To get more precise estimation of bytes sent on wire, * we add to pkt_len the headers size of all segments */ - if (unlikely(!skb_transport_header_was_set(skb))) - return; /* mac layer + network layer */ - if (!skb->encapsulation) + if (!skb->encapsulation) { + if (unlikely(!skb_transport_header_was_set(skb))) + return SKB_NOT_DROPPED_YET; hdr_len = skb_transport_offset(skb); - else + } else { hdr_len = skb_inner_transport_offset(skb); - + } /* + transport layer */ if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) { const struct tcphdr *th; - struct tcphdr _tcphdr; - th = skb_header_pointer(skb, hdr_len, - sizeof(_tcphdr), &_tcphdr); - if (likely(th)) - hdr_len += __tcp_hdrlen(th); - } else if (shinfo->gso_type & SKB_GSO_UDP_L4) { - struct udphdr _udphdr; + if (!pskb_may_pull(skb, hdr_len + sizeof(struct tcphdr))) + return SKB_DROP_REASON_SKB_BAD_GSO; - if (skb_header_pointer(skb, hdr_len, - sizeof(_udphdr), &_udphdr)) - hdr_len += sizeof(struct udphdr); + th = (const struct tcphdr *)(skb->data + hdr_len); + tlen = __tcp_hdrlen(th); + if (tlen < sizeof(*th)) + return SKB_DROP_REASON_SKB_BAD_GSO; + hdr_len += tlen; + if (!pskb_may_pull(skb, hdr_len)) + return SKB_DROP_REASON_SKB_BAD_GSO; + } else if (shinfo->gso_type & SKB_GSO_UDP_L4) { + if (!pskb_may_pull(skb, hdr_len + sizeof(struct udphdr))) + return SKB_DROP_REASON_SKB_BAD_GSO; + hdr_len += sizeof(struct udphdr); } + /* prior pskb_may_pull() might have changed skb->head. */ + shinfo = skb_shinfo(skb); if (unlikely(shinfo->gso_type & SKB_GSO_DODGY)) { int payload = skb->len - hdr_len; /* Malicious packet. */ if (payload <= 0) - return; + return SKB_DROP_REASON_SKB_BAD_GSO; gso_segs = DIV_ROUND_UP(payload, shinfo->gso_size); shinfo->gso_segs = gso_segs; qdisc_skb_cb(skb)->pkt_segs = gso_segs; } qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len; + return SKB_NOT_DROPPED_YET; } static int dev_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *q, @@ -4773,6 +4779,12 @@ int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev) (SKBTX_SCHED_TSTAMP | SKBTX_BPF))) __skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED); + reason = qdisc_pkt_len_segs_init(skb); + if (unlikely(reason)) { + dev_core_stats_tx_dropped_inc(dev); + kfree_skb_reason(skb, reason); + return -EINVAL; + } /* Disable soft irqs for various locks below. Also * stops preemption for RCU. */ @@ -4780,7 +4792,6 @@ int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev) skb_update_prio(skb); - qdisc_pkt_len_segs_init(skb); tcx_set_ingress(skb, false); #ifdef CONFIG_NET_EGRESS if (static_branch_unlikely(&egress_needed_key)) { -- 2.53.0