This is a note to let you know that I've just added the patch titled udp: fix IP_CHECKSUM handling to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: udp-fix-ip_checksum-handling.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Thu Nov 10 16:42:45 CET 2016 From: Eric Dumazet <edumazet@xxxxxxxxxx> Date: Sun, 23 Oct 2016 18:03:06 -0700 Subject: udp: fix IP_CHECKSUM handling From: Eric Dumazet <edumazet@xxxxxxxxxx> [ Upstream commit 10df8e6152c6c400a563a673e9956320bfce1871 ] First bug was added in commit ad6f939ab193 ("ip: Add offset parameter to ip_cmsg_recv") : Tom missed that ipv4 udp messages could be received on AF_INET6 socket. ip_cmsg_recv(msg, skb) should have been replaced by ip_cmsg_recv_offset(msg, skb, sizeof(struct udphdr)); Then commit e6afc8ace6dd ("udp: remove headers from UDP packets before queueing") forgot to adjust the offsets now UDP headers are pulled before skb are put in receive queue. Fixes: ad6f939ab193 ("ip: Add offset parameter to ip_cmsg_recv") Fixes: e6afc8ace6dd ("udp: remove headers from UDP packets before queueing") Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Cc: Sam Kumar <samanthakumar@xxxxxxxxxx> Cc: Willem de Bruijn <willemb@xxxxxxxxxx> Tested-by: Willem de Bruijn <willemb@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/net/ip.h | 4 ++-- net/ipv4/ip_sockglue.c | 10 ++++++---- net/ipv4/udp.c | 2 +- net/ipv6/udp.c | 3 ++- 4 files changed, 11 insertions(+), 8 deletions(-) --- a/include/net/ip.h +++ b/include/net/ip.h @@ -553,7 +553,7 @@ int ip_options_rcv_srr(struct sk_buff *s */ void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb); -void ip_cmsg_recv_offset(struct msghdr *msg, struct sk_buff *skb, int offset); +void ip_cmsg_recv_offset(struct msghdr *msg, struct sk_buff *skb, int tlen, int offset); int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc, bool allow_ipv6); int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, @@ -575,7 +575,7 @@ void ip_local_error(struct sock *sk, int static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb) { - ip_cmsg_recv_offset(msg, skb, 0); + ip_cmsg_recv_offset(msg, skb, 0, 0); } bool icmp_global_allow(void); --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -98,7 +98,7 @@ static void ip_cmsg_recv_retopts(struct } static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb, - int offset) + int tlen, int offset) { __wsum csum = skb->csum; @@ -106,7 +106,9 @@ static void ip_cmsg_recv_checksum(struct return; if (offset != 0) - csum = csum_sub(csum, csum_partial(skb->data, offset, 0)); + csum = csum_sub(csum, + csum_partial(skb->data + tlen, + offset, 0)); put_cmsg(msg, SOL_IP, IP_CHECKSUM, sizeof(__wsum), &csum); } @@ -152,7 +154,7 @@ static void ip_cmsg_recv_dstaddr(struct } void ip_cmsg_recv_offset(struct msghdr *msg, struct sk_buff *skb, - int offset) + int tlen, int offset) { struct inet_sock *inet = inet_sk(skb->sk); unsigned int flags = inet->cmsg_flags; @@ -215,7 +217,7 @@ void ip_cmsg_recv_offset(struct msghdr * } if (flags & IP_CMSG_CHECKSUM) - ip_cmsg_recv_checksum(msg, skb, offset); + ip_cmsg_recv_checksum(msg, skb, tlen, offset); } EXPORT_SYMBOL(ip_cmsg_recv_offset); --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1342,7 +1342,7 @@ try_again: *addr_len = sizeof(*sin); } if (inet->cmsg_flags) - ip_cmsg_recv_offset(msg, skb, sizeof(struct udphdr)); + ip_cmsg_recv_offset(msg, skb, sizeof(struct udphdr), off); err = copied; if (flags & MSG_TRUNC) --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -498,7 +498,8 @@ try_again: if (is_udp4) { if (inet->cmsg_flags) - ip_cmsg_recv(msg, skb); + ip_cmsg_recv_offset(msg, skb, + sizeof(struct udphdr), off); } else { if (np->rxopt.all) ip6_datagram_recv_specific_ctl(sk, msg, skb); Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are queue-4.4/ipv4-use-the-right-lock-for-ping_group_range.patch queue-4.4/ipv4-disable-bh-in-set_ping_group_range.patch queue-4.4/tcp-fix-a-compile-error-in-dbgundo.patch queue-4.4/net-avoid-sk_forward_alloc-overflows.patch queue-4.4/udp-fix-ip_checksum-handling.patch queue-4.4/netlink-do-not-enter-direct-reclaim-from-netlink_dump.patch queue-4.4/ipv6-tcp-restore-ip6cb-for-pktoptions-skbs.patch queue-4.4/tcp-fix-overflow-in-__tcp_retransmit_skb.patch queue-4.4/packet-on-direct_xmit-limit-tso-and-csum-to-supported-devices.patch queue-4.4/net-pktgen-remove-rcu-locking-in-pktgen_change_name.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html