BMC/Intel-BMC/linux.git/net/ipv4, branch v4.18.11

udp4: fix IP_CMSG_CHECKSUM for connected sockets

2018-09-29T09:55:52+00:00

[ Upstream commit 2b5a921740a55c00223a797d075b9c77c42cb171 ] commit 2abb7cdc0dc8 ("udp: Add support for doing checksum unnecessary conversion") left out the early demux path for connected sockets. As a result IP_CMSG_CHECKSUM gives wrong values for such socket when GRO is not enabled/available. This change addresses the issue by moving the csum conversion to a common helper and using such helper in both the default and the early demux rx path. Fixes: 2abb7cdc0dc8 ("udp: Add support for doing checksum unnecessary conversion") Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

gso_segment: Reset skb->mac_len after modifying network header

2018-09-29T09:55:51+00:00

[ Upstream commit c56cae23c6b167acc68043c683c4573b80cbcc2c ] When splitting a GSO segment that consists of encapsulated packets, the skb->mac_len of the segments can end up being set wrong, causing packet drops in particular when using act_mirred and ifb interfaces in combination with a qdisc that splits GSO packets. This happens because at the time skb_segment() is called, network_header will point to the inner header, throwing off the calculation in skb_reset_mac_len(). The network_header is subsequently adjust by the outer IP gso_segment handlers, but they don't set the mac_len. Fix this by adding skb_reset_mac_len() calls to both the IPv4 and IPv6 gso_segment handlers, after they modify the network_header. Many thanks to Eric Dumazet for his help in identifying the cause of the bug. Acked-by: Dave Taht Reviewed-by: Eric Dumazet Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: really ignore MSG_ZEROCOPY if no SO_ZEROCOPY

2018-09-26T06:39:20+00:00

[ Upstream commit 5cf4a8532c992bb22a9ecd5f6d93f873f4eaccc2 ] According to the documentation in msg_zerocopy.rst, the SO_ZEROCOPY flag was introduced because send(2) ignores unknown message flags and any legacy application which was accidentally passing the equivalent of MSG_ZEROCOPY earlier should not see any new behaviour. Before commit f214f915e7db ("tcp: enable MSG_ZEROCOPY"), a send(2) call which passed the equivalent of MSG_ZEROCOPY without setting SO_ZEROCOPY would succeed. However, after that commit, it fails with -ENOBUFS. So it appears that the SO_ZEROCOPY flag fails to fulfill its intended purpose. Fix it. Fixes: f214f915e7db ("tcp: enable MSG_ZEROCOPY") Signed-off-by: Vincent Whitchurch Acked-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

erspan: return PACKET_REJECT when the appropriate tunnel is not found

2018-09-26T06:39:20+00:00

[ Upstream commit 5a64506b5c2c3cdb29d817723205330378075448 ] If erspan tunnel hasn't been established, we'd better send icmp port unreachable message after receive erspan packets. Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN") Cc: William Tu Signed-off-by: Haishuang Yan Acked-by: William Tu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

erspan: fix error handling for erspan tunnel

2018-09-26T06:39:20+00:00

[ Upstream commit 51dc63e3911fbb1f0a7a32da2fe56253e2040ea4 ] When processing icmp unreachable message for erspan tunnel, tunnel id should be erspan_net_id instead of ipgre_net_id. Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN") Cc: William Tu Signed-off-by: Haishuang Yan Acked-by: William Tu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp, ulp: add alias for all ulp modules

2018-09-15T07:46:49+00:00

[ Upstream commit 037b0b86ecf5646f8eae777d8b52ff8b401692ec ] Lets not turn the TCP ULP lookup into an arbitrary module loader as we only intend to load ULP modules through this mechanism, not other unrelated kernel modules: [root@bar]# cat foo.c #include #include #include #include int main(void) { int sock = socket(PF_INET, SOCK_STREAM, 0); setsockopt(sock, IPPROTO_TCP, TCP_ULP, "sctp", sizeof("sctp")); return 0; } [root@bar]# gcc foo.c -O2 -Wall [root@bar]# lsmod | grep sctp [root@bar]# ./a.out [root@bar]# lsmod | grep sctp sctp 1077248 4 libcrc32c 16384 3 nf_conntrack,nf_nat,sctp [root@bar]# Fix it by adding module alias to TCP ULP modules, so probing module via request_module() will be limited to tcp-ulp-[name]. The existing modules like kTLS will load fine given tcp-ulp-tls alias, but others will fail to load: [root@bar]# lsmod | grep sctp [root@bar]# ./a.out [root@bar]# lsmod | grep sctp [root@bar]# Sockmap is not affected from this since it's either built-in or not. Fixes: 734942cc4ea6 ("tcp: ULP infrastructure") Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Acked-by: Song Liu Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

tcp, ulp: fix leftover icsk_ulp_ops preventing sock from reattach

2018-09-15T07:46:48+00:00

[ Upstream commit 90545cdc3f2b2ea700e24335610cd181e73756da ] I found that in BPF sockmap programs once we either delete a socket from the map or we updated a map slot and the old socket was purged from the map that these socket can never get reattached into a map even though their related psock has been dropped entirely at that point. Reason is that tcp_cleanup_ulp() leaves the old icsk->icsk_ulp_ops intact, so that on the next tcp_set_ulp_id() the kernel returns an -EEXIST thinking there is still some active ULP attached. BPF sockmap is the only one that has this issue as the other user, kTLS, only calls tcp_cleanup_ulp() from tcp_v4_destroy_sock() whereas sockmap semantics allow dropping the socket from the map with all related psock state being cleaned up. Fixes: 1aa12bdf1bfb ("bpf: sockmap, add sock close() hook to remove socks") Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Acked-by: Song Liu Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

erspan: set erspan_ver to 1 by default when adding an erspan dev

2018-09-15T07:46:42+00:00

[ Upstream commit 84581bdae9587023cea1d139523f0ef0f28bd88d ] After erspan_ver is introudced, if erspan_ver is not set in iproute, its value will be left 0 by default. Since Commit 02f99df1875c ("erspan: fix invalid erspan version."), it has broken the traffic due to the version check in erspan_xmit if users are not aware of 'erspan_ver' param, like using an old version of iproute. To fix this compatibility problem, it sets erspan_ver to 1 by default when adding an erspan dev in erspan_setup. Note that we can't do it in ipgre_netlink_parms, as this function is also used by ipgre_changelink. Fixes: 02f99df1875c ("erspan: fix invalid erspan version.") Reported-by: Jianlin Shi Signed-off-by: Xin Long Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: do not restart timewait timer on rst reception

2018-09-15T07:46:41+00:00

[ Upstream commit 63cc357f7bba6729869565a12df08441a5995d9a ] RFC 1337 says: ''Ignore RST segments in TIME-WAIT state. If the 2 minute MSL is enforced, this fix avoids all three hazards.'' So with net.ipv4.tcp_rfc1337=1, expected behaviour is to have TIME-WAIT sk expire rather than removing it instantly when a reset is received. However, Linux will also re-start the TIME-WAIT timer. This causes connect to fail when tying to re-use ports or very long delays (until syn retry interval exceeds MSL). packetdrill test case: // Demonstrate bogus rearming of TIME-WAIT timer in rfc1337 mode. `sysctl net.ipv4.tcp_rfc1337=1` 0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 0.000 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 0.000 bind(3, ..., ...) = 0 0.000 listen(3, 1) = 0 0.100 < S 0:0(0) win 29200 0.100 > S. 0:0(0) ack 1 0.200 < . 1:1(0) ack 1 win 257 0.200 accept(3, ..., ...) = 4 // Receive first segment 0.310 < P. 1:1001(1000) ack 1 win 46 // Send one ACK 0.310 > . 1:1(0) ack 1001 // read 1000 byte 0.310 read(4, ..., 1000) = 1000 // Application writes 100 bytes 0.350 write(4, ..., 100) = 100 0.350 > P. 1:101(100) ack 1001 // ACK 0.500 < . 1001:1001(0) ack 101 win 257 // close the connection 0.600 close(4) = 0 0.600 > F. 101:101(0) ack 1001 win 244 // Our side is in FIN_WAIT_1 & waits for ack to fin 0.7 < . 1001:1001(0) ack 102 win 244 // Our side is in FIN_WAIT_2 with no outstanding data. 0.8 < F. 1001:1001(0) ack 102 win 244 0.8 > . 102:102(0) ack 1002 win 244 // Our side is now in TIME_WAIT state, send ack for fin. 0.9 < F. 1002:1002(0) ack 102 win 244 0.9 > . 102:102(0) ack 1002 win 244 // Peer reopens with in-window SYN: 1.000 < S 1000:1000(0) win 9200 // Therefore, reply with ACK. 1.000 > . 102:102(0) ack 1002 win 244 // Peer sends RST for this ACK. Normally this RST results // in tw socket removal, but rfc1337=1 setting prevents this. 1.100 < R 1002:1002(0) win 244 // second syn. Due to rfc1337=1 expect another pure ACK. 31.0 < S 1000:1000(0) win 9200 31.0 > . 102:102(0) ack 1002 win 244 // .. and another RST from peer. 31.1 < R 1002:1002(0) win 244 31.2 `echo no timer restart;ss -m -e -a -i -n -t -o state TIME-WAIT` // third syn after one minute. Time-Wait socket should have expired by now. 63.0 < S 1000:1000(0) win 9200 // so we expect a syn-ack & 3whs to proceed from here on. 63.0 > S. 0:0(0) ack 1 Without this patch, 'ss' shows restarts of tw timer and last packet is thus just another pure ack, more than one minute later. This restores the original code from commit 283fd6cf0be690a83 ("Merge in ANK networking jumbo patch") in netdev-vger-cvs.git . For some reason the else branch was removed/lost in 1f28b683339f7 ("Merge in TCP/UDP optimizations and [..]") and timer restart became unconditional. Reported-by: Michal Tesar Signed-off-by: Florian Westphal Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: tcp: send zero IPID for RST and ACK sent in SYN-RECV and TIME-WAIT state

2018-09-15T07:46:40+00:00

[ Upstream commit 431280eebed9f5079553daf003011097763e71fd ] tcp uses per-cpu (and per namespace) sockets (net->ipv4.tcp_sk) internally to send some control packets. 1) RST packets, through tcp_v4_send_reset() 2) ACK packets in SYN-RECV and TIME-WAIT state, through tcp_v4_send_ack() These packets assert IP_DF, and also use the hashed IP ident generator to provide an IPv4 ID number. Geoff Alexander reported this could be used to build off-path attacks. These packets should not be fragmented, since their size is smaller than IPV4_MIN_MTU. Only some tunneled paths could eventually have to fragment, regardless of inner IPID. We really can use zero IPID, to address the flaw, and as a bonus, avoid a couple of atomic operations in ip_idents_reserve() Signed-off-by: Eric Dumazet Reported-by: Geoff Alexander Tested-by: Geoff Alexander Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman