From patchwork Fri Mar 22 11:46:20 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antoine Tenart X-Patchwork-Id: 13599996 X-Patchwork-Delegate: kuba@kernel.org Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8E15E224FA for ; Fri, 22 Mar 2024 11:46:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711107990; cv=none; b=rK6odwQ9Vrrt4QSdrSutEynwQfFyucAB8hhy5etoAM1dtTM8Fc+e6MeP/PdCV3VP106MJw4/KTWpVJqtkTi3MVoCS6zoD+yPL0SZ/jJ52VBdftZ0hFOhylcho5dd0hsp9ERCrISvEl9pwwycsj5sij0M9z9TkL+bnxnye1+DvXc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711107990; c=relaxed/simple; bh=x4YH3OhXZnwtL2VG55Qju0hX04ZVvudFCYZzBZkH1gg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WiSkmP4SZ7iOm+X7AfCMBAKwFTKqmmm44COmq5SM2qzr+prVa7SwP1ptN/TX8qalyUKmeGw4CTxkIbvAohLP0ttt+8taEpmJYSjzlgs8StXLa1rB/L8XqekAKvDNRF1qvIN92k0xHw9X52AOmyXlKf6MxlF8Zar6tCnrmA6pBC0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HcJZfumD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HcJZfumD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA2DBC433C7; Fri, 22 Mar 2024 11:46:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711107990; bh=x4YH3OhXZnwtL2VG55Qju0hX04ZVvudFCYZzBZkH1gg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HcJZfumDaW+UlZD8LWeQhxFuW+q+92QXXcxUVFe8adMJs0vxnhnlsWM+2P4be4FU+ TbuGGVPmjSZvIChUMfaKawLQZs0D5sF1F3FIwpijgry14rf99FsNEuItg14sG/pGRL 0Z6FV1F1vKcIPhQwEo0wmyyDYqjSvHRI8ku/UiMxk/HFvhXu0ShGNzyNUmtfzW/X/i OeVqAaWf9C8lZ0ZHbNiJDlaFfsiSKcuQ99FpqYo83lKM/0ePoUhlHBJ8urZez+81GF 4Qqjw5m02/Wpavebq3NWki3TFxHyVpn1ukQ4DGF6Uif6Ad9edOu5oMG7Q+6klS6fgQ EJJcsHoYijQnw== From: Antoine Tenart To: davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com Cc: Antoine Tenart , steffen.klassert@secunet.com, willemdebruijn.kernel@gmail.com, netdev@vger.kernel.org, Willem de Bruijn Subject: [PATCH net v3 1/4] udp: do not accept non-tunnel GSO skbs landing in a tunnel Date: Fri, 22 Mar 2024 12:46:20 +0100 Message-ID: <20240322114624.160306-2-atenart@kernel.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240322114624.160306-1-atenart@kernel.org> References: <20240322114624.160306-1-atenart@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org When rx-udp-gro-forwarding is enabled UDP packets might be GROed when being forwarded. If such packets might land in a tunnel this can cause various issues and udp_gro_receive makes sure this isn't the case by looking for a matching socket. This is performed in udp4/6_gro_lookup_skb but only in the current netns. This is an issue with tunneled packets when the endpoint is in another netns. In such cases the packets will be GROed at the UDP level, which leads to various issues later on. The same thing can happen with rx-gro-list. We saw this with geneve packets being GROed at the UDP level. In such case gso_size is set; later the packet goes through the geneve rx path, the geneve header is pulled, the offset are adjusted and frag_list skbs are not adjusted with regard to geneve. When those skbs hit skb_fragment, it will misbehave. Different outcomes are possible depending on what the GROed skbs look like; from corrupted packets to kernel crashes. One example is a BUG_ON[1] triggered in skb_segment while processing the frag_list. Because gso_size is wrong (geneve header was pulled) skb_segment thinks there is "geneve header size" of data in frag_list, although it's in fact the next packet. The BUG_ON itself has nothing to do with the issue. This is only one of the potential issues. Looking up for a matching socket in udp_gro_receive is fragile: the lookup could be extended to all netns (not speaking about performances) but nothing prevents those packets from being modified in between and we could still not find a matching socket. It's OK to keep the current logic there as it should cover most cases but we also need to make sure we handle tunnel packets being GROed too early. This is done by extending the checks in udp_unexpected_gso: GSO packets lacking the SKB_GSO_UDP_TUNNEL/_CSUM bits and landing in a tunnel must be segmented. [1] kernel BUG at net/core/skbuff.c:4408! RIP: 0010:skb_segment+0xd2a/0xf70 __udp_gso_segment+0xaa/0x560 Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") Fixes: 36707061d6ba ("udp: allow forwarding of plain (non-fraglisted) UDP GRO packets") Signed-off-by: Antoine Tenart Reviewed-by: Willem de Bruijn --- include/linux/udp.h | 28 ++++++++++++++++++++++++++++ net/ipv4/udp.c | 7 +++++++ net/ipv4/udp_offload.c | 6 ++++-- net/ipv6/udp.c | 2 +- 4 files changed, 40 insertions(+), 3 deletions(-) diff --git a/include/linux/udp.h b/include/linux/udp.h index 3748e82b627b..17539d089666 100644 --- a/include/linux/udp.h +++ b/include/linux/udp.h @@ -150,6 +150,24 @@ static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk, } } +DECLARE_STATIC_KEY_FALSE(udp_encap_needed_key); +#if IS_ENABLED(CONFIG_IPV6) +DECLARE_STATIC_KEY_FALSE(udpv6_encap_needed_key); +#endif + +static inline bool udp_encap_needed(void) +{ + if (static_branch_unlikely(&udp_encap_needed_key)) + return true; + +#if IS_ENABLED(CONFIG_IPV6) + if (static_branch_unlikely(&udpv6_encap_needed_key)) + return true; +#endif + + return false; +} + static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb) { if (!skb_is_gso(skb)) @@ -163,6 +181,16 @@ static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb) !udp_test_bit(ACCEPT_FRAGLIST, sk)) return true; + /* GSO packets lacking the SKB_GSO_UDP_TUNNEL/_CSUM bits might still + * land in a tunnel as the socket check in udp_gro_receive cannot be + * foolproof. + */ + if (udp_encap_needed() && + READ_ONCE(udp_sk(sk)->encap_rcv) && + !(skb_shinfo(skb)->gso_type & + (SKB_GSO_UDP_TUNNEL | SKB_GSO_UDP_TUNNEL_CSUM))) + return true; + return false; } diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 661d0e0d273f..c02bf011d4a6 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -582,6 +582,13 @@ static inline bool __udp_is_mcast_sock(struct net *net, const struct sock *sk, } DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key); +EXPORT_SYMBOL(udp_encap_needed_key); + +#if IS_ENABLED(CONFIG_IPV6) +DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key); +EXPORT_SYMBOL(udpv6_encap_needed_key); +#endif + void udp_encap_enable(void) { static_branch_inc(&udp_encap_needed_key); diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index b9880743765c..e9719afe91cf 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -551,8 +551,10 @@ struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb, unsigned int off = skb_gro_offset(skb); int flush = 1; - /* we can do L4 aggregation only if the packet can't land in a tunnel - * otherwise we could corrupt the inner stream + /* We can do L4 aggregation only if the packet can't land in a tunnel + * otherwise we could corrupt the inner stream. Detecting such packets + * cannot be foolproof and the aggregation might still happen in some + * cases. Such packets should be caught in udp_unexpected_gso later. */ NAPI_GRO_CB(skb)->is_flist = 0; if (!sk || !udp_sk(sk)->gro_receive) { diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 7c1e6469d091..8b1dd7f51249 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -447,7 +447,7 @@ int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, goto try_again; } -DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key); +DECLARE_STATIC_KEY_FALSE(udpv6_encap_needed_key); void udpv6_encap_enable(void) { static_branch_inc(&udpv6_encap_needed_key); From patchwork Fri Mar 22 11:46:21 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antoine Tenart X-Patchwork-Id: 13599997 X-Patchwork-Delegate: kuba@kernel.org Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 03F3D3F9D5 for ; Fri, 22 Mar 2024 11:46:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711107994; cv=none; b=AZ8L/dbDBEfhs+yFT3Ub7XyvMx+PUcaSDMzyaRNfYLt70SqQgLGxUlPTwsfgYAot+uJYuCbD69XQsyLX6slyw3i7nWZnKAjpgyMvVfQkhc2AFx8FuGQqWJ2u3GJW+AqnD4uA0XI7Bmqo5CI7TO5UwM1uy6+YcnYTwTBruPg1f6w= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711107994; c=relaxed/simple; bh=9AGZg+Pbqwe5RkEz1eQH+VUG1GXVEpPCjOgQ8W1uVY4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bViErqxZwWSX+p889XKkdexLj52DNXZY+CAb+WTP9MmhKPTDIv37S4L9da5WV83qMwGQOJF4IJMBeafrQbIrSgzb7NbSZjKqfjtAEN8O9VCSKh32wkIO0MMDtmjNNa8jtwa3LLY2Y9aUlCw43TdEiIlh0W4CNqB8wDO/c08lsPE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qP9Wq7e7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qP9Wq7e7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 267C6C433F1; Fri, 22 Mar 2024 11:46:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711107993; bh=9AGZg+Pbqwe5RkEz1eQH+VUG1GXVEpPCjOgQ8W1uVY4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qP9Wq7e7GlrDVg9hWQ8pcJITvd/9rTkDXgozhRv9fLRHr0gheIRAD6omJ2C6TulQa L7vx/8N79cAKrFXKDbTi7sMBSIQchaBOjYJzBM1ds6DodEqBtXB6UoLgcTZo2IRpjJ MpfuQz40qBfUwn/+HSK48b804EpDQ0CmVZde/+UFmQBq3m87TVxCKzfGYeSNOSnlio a4s4LXg6ikb+080mrELxTWqMpTSNCse50Y6XD6aF10u9nqgs1aENbeTwzAfZp0ftbS oDZjAA8ltjlvo/lBEoaMTWdxOUb1JJm3WLJwXzrUPJY08BqT3EuixKFPcs+PDQhTKI 0kTBGM128Q6LQ== From: Antoine Tenart To: davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com Cc: Antoine Tenart , steffen.klassert@secunet.com, willemdebruijn.kernel@gmail.com, netdev@vger.kernel.org, Willem de Bruijn Subject: [PATCH net v3 2/4] gro: fix ownership transfer Date: Fri, 22 Mar 2024 12:46:21 +0100 Message-ID: <20240322114624.160306-3-atenart@kernel.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240322114624.160306-1-atenart@kernel.org> References: <20240322114624.160306-1-atenart@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org If packets are GROed with fraglist they might be segmented later on and continue their journey in the stack. In skb_segment_list those skbs can be reused as-is. This is an issue as their destructor was removed in skb_gro_receive_list but not the reference to their socket, and then they can't be orphaned. Fix this by also removing the reference to the socket. For example this could be observed, kernel BUG at include/linux/skbuff.h:3131! (skb_orphan) RIP: 0010:ip6_rcv_core+0x11bc/0x19a0 Call Trace: ipv6_list_rcv+0x250/0x3f0 __netif_receive_skb_list_core+0x49d/0x8f0 netif_receive_skb_list_internal+0x634/0xd40 napi_complete_done+0x1d2/0x7d0 gro_cell_poll+0x118/0x1f0 A similar construction is found in skb_gro_receive, apply the same change there. Fixes: 5e10da5385d2 ("skbuff: allow 'slow_gro' for skb carring sock reference") Signed-off-by: Antoine Tenart Reviewed-by: Willem de Bruijn --- net/core/gro.c | 3 ++- net/ipv4/udp_offload.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/net/core/gro.c b/net/core/gro.c index ee30d4f0c038..83f35d99a682 100644 --- a/net/core/gro.c +++ b/net/core/gro.c @@ -192,8 +192,9 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb) } merge: - /* sk owenrship - if any - completely transferred to the aggregated packet */ + /* sk ownership - if any - completely transferred to the aggregated packet */ skb->destructor = NULL; + skb->sk = NULL; delta_truesize = skb->truesize; if (offset > headlen) { unsigned int eat = offset - headlen; diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index e9719afe91cf..3bb69464930b 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -449,8 +449,9 @@ static int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb) NAPI_GRO_CB(p)->count++; p->data_len += skb->len; - /* sk owenrship - if any - completely transferred to the aggregated packet */ + /* sk ownership - if any - completely transferred to the aggregated packet */ skb->destructor = NULL; + skb->sk = NULL; p->truesize += skb->truesize; p->len += skb->len; From patchwork Fri Mar 22 11:46:22 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antoine Tenart X-Patchwork-Id: 13599998 X-Patchwork-Delegate: kuba@kernel.org Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D1FB23F9E4 for ; Fri, 22 Mar 2024 11:46:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711107996; cv=none; b=kM4NDWnDPN10r1+q/AVbu7NJ9boNOvmYVVTgHDjjLwmjmNnkTk6Iwn/xC5G3KBL5fIYj/RSiYRc8Ms11K74mTUrmr6i2r27kloQano6UTJK4MfhEKHBWCWMA34jFhmHETWqqE+8lEBYydfuWcGB23MQV4dPJyfAOPSO1mcq3fUw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711107996; c=relaxed/simple; bh=MpxNCWYDdPoEhBAvl91XieIM9R6eDIeYvHrj2xd0Y3c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WxE1Vbd5Gczv2rPY3UGjj5xKwOCClJyyj4DrasmWYgufph0AnuqJT/vB71noMGPW43hXUO4e55h/XNTi1E8D7uVAd79EIRUCvYMES6vXN8LEzCwiUqTrQ2FTjyRUDQaSOg0sL0zgMT2+rPczgZDPLKgwLbk2V67InMHVEKNeupc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UZQK5mXo; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UZQK5mXo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE6B7C433F1; Fri, 22 Mar 2024 11:46:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711107996; bh=MpxNCWYDdPoEhBAvl91XieIM9R6eDIeYvHrj2xd0Y3c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UZQK5mXo3asX4/+7FOLoj/HwqP7PZpiNk31/q05xWjJouG1IgMMQDf3P3FwjBB189 dqNKxtH406RKW+OQ/FQdOzE0kkfk9kUjrHkWJFTLHIKynyH8zyb/6BK3CkwKGPISm9 uafH/F73qujY/OalxVnuh+fj26Wau2y4DNqwiJ0/+8Lye763TZJT1vsIyVissO1Nl7 2N+VdixdeJbwLQgLdTdrH67+QNuyB78BPM+xeBAhY1HtlvmgiKZFPzWJ3jZCSPN61q sIfQDesShMddqoGrufY00plaKxN7mhhrjENvplu3bKugbQWItuC4kyWxy3wgW/0hyI E9+ndMLZdwUqQ== From: Antoine Tenart To: davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com Cc: Antoine Tenart , steffen.klassert@secunet.com, willemdebruijn.kernel@gmail.com, netdev@vger.kernel.org Subject: [PATCH net v3 3/4] udp: do not transition UDP GRO fraglist partial checksums to unnecessary Date: Fri, 22 Mar 2024 12:46:22 +0100 Message-ID: <20240322114624.160306-4-atenart@kernel.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240322114624.160306-1-atenart@kernel.org> References: <20240322114624.160306-1-atenart@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org UDP GRO validates checksums and in udp4/6_gro_complete fraglist packets are converted to CHECKSUM_UNNECESSARY to avoid later checks. However this is an issue for CHECKSUM_PARTIAL packets as they can be looped in an egress path and then their partial checksums are not fixed. Different issues can be observed, from invalid checksum on packets to traces like: gen01: hw csum failure skb len=3008 headroom=160 headlen=1376 tailroom=0 mac=(106,14) net=(120,40) trans=160 shinfo(txflags=0 nr_frags=0 gso(size=0 type=0 segs=0)) csum(0xffff232e ip_summed=2 complete_sw=0 valid=0 level=0) hash(0x77e3d716 sw=1 l4=1) proto=0x86dd pkttype=0 iif=12 ... Fix this by only converting CHECKSUM_NONE packets to CHECKSUM_UNNECESSARY by reusing __skb_incr_checksum_unnecessary. Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") Signed-off-by: Antoine Tenart --- net/ipv4/udp_offload.c | 8 +------- net/ipv6/udp_offload.c | 8 +------- 2 files changed, 2 insertions(+), 14 deletions(-) diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 3bb69464930b..548476d78237 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -722,13 +722,7 @@ INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff) skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4); skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; - if (skb->ip_summed == CHECKSUM_UNNECESSARY) { - if (skb->csum_level < SKB_MAX_CSUM_LEVEL) - skb->csum_level++; - } else { - skb->ip_summed = CHECKSUM_UNNECESSARY; - skb->csum_level = 0; - } + __skb_incr_checksum_unnecessary(skb); return 0; } diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c index 312bcaeea96f..bbd347de00b4 100644 --- a/net/ipv6/udp_offload.c +++ b/net/ipv6/udp_offload.c @@ -174,13 +174,7 @@ INDIRECT_CALLABLE_SCOPE int udp6_gro_complete(struct sk_buff *skb, int nhoff) skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4); skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; - if (skb->ip_summed == CHECKSUM_UNNECESSARY) { - if (skb->csum_level < SKB_MAX_CSUM_LEVEL) - skb->csum_level++; - } else { - skb->ip_summed = CHECKSUM_UNNECESSARY; - skb->csum_level = 0; - } + __skb_incr_checksum_unnecessary(skb); return 0; } From patchwork Fri Mar 22 11:46:23 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antoine Tenart X-Patchwork-Id: 13600001 X-Patchwork-Delegate: kuba@kernel.org Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 99E4C3EA83 for ; Fri, 22 Mar 2024 11:46:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711107999; cv=none; b=YKuCMUXNpmlL3CE/wwcUdPaJ+vqKJtQcPfGmgKbeqUDS0ZaeXqHZnZhhPr99pTC2KGKcY/TWvtoEVmy9hSrmNzYZsPg95b9GYxrZMpq6I/gfIo5fOjaz0B1mb9Sfw0S0TFfAqxASsHpJVa6lr71kVPQBGHXwjib3UesWVNQyKHs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711107999; c=relaxed/simple; bh=lNZ3GsF+2FDIGqDK/pc65J09dJNN1ybvqZZZwXWhNVs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tn3/mwLYo96xZ/kzOkk8kHYCytSfRWDzrvRJ6cVB6DFpvNQ1by2JCX/wgHZ3XEYvmBzt3PLrkbhuq+CYnDME7Iby/WnUjsOEGhTNkkgdFAFUPRhOB7FhDFtsqdd2mCJvpSGjWe7EU8BK/hvJmHpL7+NYxrsfyHCfXhuwRd96J6I= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TRQg4/9Z; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TRQg4/9Z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1929C433F1; Fri, 22 Mar 2024 11:46:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711107999; bh=lNZ3GsF+2FDIGqDK/pc65J09dJNN1ybvqZZZwXWhNVs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TRQg4/9Z7ELjfF+iw/+w0dnGSUh6pJXiPqoreaOK9gttvaRQDQ0gAnUxMupKMjEo+ eJU+xRcCYFgpicIfORSxAYW2GWv8XvCHR8Cd27ppHnQ8cP80MfXumel/+w0fSsHC2c /Cf0XM+gDkZJgGbQOj2FdE5xZ2CHCdMAcvVXCgYPeaNxHXRYChK2qj/j0icueL8SM8 d9DHw0GMr/nT7j5g3q40Fzrx3dcXagfUGOCQSfYsngjYMzym5aEr2P2TTukrQ8mVRY SQ1Q+omtgk0CEuPKwI+yeWjFrScIqyIvKayQWFaLLWcvVBypuFKNsIJEpc9zyl2+UE doA3LNPWZskRA== From: Antoine Tenart To: davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com Cc: Antoine Tenart , steffen.klassert@secunet.com, willemdebruijn.kernel@gmail.com, netdev@vger.kernel.org, Willem de Bruijn Subject: [PATCH net v3 4/4] udp: prevent local UDP tunnel packets from being GROed Date: Fri, 22 Mar 2024 12:46:23 +0100 Message-ID: <20240322114624.160306-5-atenart@kernel.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240322114624.160306-1-atenart@kernel.org> References: <20240322114624.160306-1-atenart@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org GRO has a fundamental issue with UDP tunnel packets as it can't detect those in a foolproof way and GRO could happen before they reach the tunnel endpoint. Previous commits have fixed issues when UDP tunnel packets come from a remote host, but if those packets are issued locally they could run into checksum issues. If the inner packet has a partial checksum the information will be lost in the GRO logic, either in udp4/6_gro_complete or in udp_gro_complete_segment and packets will have an invalid checksum when leaving the host. Prevent local UDP tunnel packets from ever being GROed at the outer UDP level. Due to skb->encapsulation being wrongly used in some drivers this is actually only preventing UDP tunnel packets with a partial checksum to be GROed (see iptunnel_handle_offloads) but those were also the packets triggering issues so in practice this should be sufficient. Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") Fixes: 36707061d6ba ("udp: allow forwarding of plain (non-fraglisted) UDP GRO packets") Suggested-by: Paolo Abeni Signed-off-by: Antoine Tenart Reviewed-by: Willem de Bruijn --- net/ipv4/udp_offload.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 548476d78237..3498dd1d0694 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -559,6 +559,12 @@ struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb, */ NAPI_GRO_CB(skb)->is_flist = 0; if (!sk || !udp_sk(sk)->gro_receive) { + /* If the packet was locally encapsulated in a UDP tunnel that + * wasn't detected above, do not GRO. + */ + if (skb->encapsulation) + goto out; + if (skb->dev->features & NETIF_F_GRO_FRAGLIST) NAPI_GRO_CB(skb)->is_flist = sk ? !udp_test_bit(GRO_ENABLED, sk) : 1;