From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELufIMFqa8tIvOjoAFK4qy/5NhOXj3kTzaffE4abKhHoQJUEdGdHkdrfXJ6nysRyLjeatn1N ARC-Seal: i=1; a=rsa-sha256; t=1520641239; cv=none; d=google.com; s=arc-20160816; b=wy4RFgtcnhgwNk3qYbKoW0Thd4zcPMs4L+cwsY1qw4dpLgZVF3AJ7DiE2LqvW1p1ml OZ17kLjw9NZXn5fJh1BXoNarguCyZQFkaE+4rFBvHMwwDfMeMVWBXEhs2E9UVLuBsg7G HatnjWMZf6my29oMox5H/Inm3KSnFICzcWfXLRHLcTSaKMrpCQL24+s16fkD+ATLMrLS s70USfFdsp+SRxN6cCKBSA/Kzv68YkDxmZdcl/QncIJkWhTjBDqGQwMF4yiAD3AG+yWB K1Fdwb+Q19pzTmfO54UD5ef7s7/r/hHp/SPFlSCQVYWCGsTK1XFRGpXRmDmjBpkFD2MR x1lg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=1yPXVAMJYGM0ljkIAy3P2iD7ZyG8ZPz3eCOq7KQJMY0=; b=hCTHrDvif6HB0xcMN5naH0E1xix/3cCBdUM2aO2IPJhx0uM7d5REfMaa/hgKiOqmqs FpPNNnyRku8rYJ5vvhttRUFebXAEvoq0XqndPkT/WmYbkZmbGhrb6ozkTTWoblWwHjfw sMVg52fAI+Gce1NXF9+fcPgfXsrQGMAtjaTpDEOBl9vVl74Uob4FOFOaT0wVdu3nngYX TSzUh1124RUNNgpDovVXmMWbiAuHBfga8Yg0NW/s6R5Wyjt3qghFU2NM9Mr0GnvDnw45 2a/MhlFOmH3yaPqyecffI8mlkOpv7fx0QJ11nSjPAXFDflU1EkTzzf65ew2o5R2ISDAH Medg== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 185.236.200.248 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 185.236.200.248 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexey Kodanev , "David S. Miller" Subject: [PATCH 4.4 26/36] udplite: fix partial checksum initialization Date: Fri, 9 Mar 2018 16:18:42 -0800 Message-Id: <20180310001808.796588951@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180310001807.213987241@linuxfoundation.org> References: <20180310001807.213987241@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1594507822208256184?= X-GMAIL-MSGID: =?utf-8?q?1594507908261792641?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexey Kodanev [ Upstream commit 15f35d49c93f4fa9875235e7bf3e3783d2dd7a1b ] Since UDP-Lite is always using checksum, the following path is triggered when calculating pseudo header for it: udp4_csum_init() or udp6_csum_init() skb_checksum_init_zero_check() __skb_checksum_validate_complete() The problem can appear if skb->len is less than CHECKSUM_BREAK. In this particular case __skb_checksum_validate_complete() also invokes __skb_checksum_complete(skb). If UDP-Lite is using partial checksum that covers only part of a packet, the function will return bad checksum and the packet will be dropped. It can be fixed if we skip skb_checksum_init_zero_check() and only set the required pseudo header checksum for UDP-Lite with partial checksum before udp4_csum_init()/udp6_csum_init() functions return. Fixes: ed70fcfcee95 ("net: Call skb_checksum_init in IPv4") Fixes: e4f45b7f40bd ("net: Call skb_checksum_init in IPv6") Signed-off-by: Alexey Kodanev Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- include/net/udplite.h | 1 + net/ipv4/udp.c | 5 +++++ net/ipv6/ip6_checksum.c | 5 +++++ 3 files changed, 11 insertions(+) --- a/include/net/udplite.h +++ b/include/net/udplite.h @@ -62,6 +62,7 @@ static inline int udplite_checksum_init( UDP_SKB_CB(skb)->cscov = cscov; if (skb->ip_summed == CHECKSUM_COMPLETE) skb->ip_summed = CHECKSUM_NONE; + skb->csum_valid = 0; } return 0; --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1744,6 +1744,11 @@ static inline int udp4_csum_init(struct err = udplite_checksum_init(skb, uh); if (err) return err; + + if (UDP_SKB_CB(skb)->partial_cov) { + skb->csum = inet_compute_pseudo(skb, proto); + return 0; + } } return skb_checksum_init_zero_check(skb, proto, uh->check, --- a/net/ipv6/ip6_checksum.c +++ b/net/ipv6/ip6_checksum.c @@ -73,6 +73,11 @@ int udp6_csum_init(struct sk_buff *skb, err = udplite_checksum_init(skb, uh); if (err) return err; + + if (UDP_SKB_CB(skb)->partial_cov) { + skb->csum = ip6_compute_pseudo(skb, proto); + return 0; + } } /* To support RFC 6936 (allow zero checksum in UDP/IPV6 for tunnels)