linux/include/net/netns, branch v5.2

tcp: add tcp_min_snd_mss sysctl

2019-06-16T01:47:31Z

Some TCP peers announce a very small MSS option in their SYN and/or SYN/ACK messages. This forces the stack to send packets with a very high network/cpu overhead. Linux has enforced a minimal value of 48. Since this value includes the size of TCP options, and that the options can consume up to 40 bytes, this means that each segment can include only 8 bytes of payload. In some cases, it can be useful to increase the minimal value to a saner value. We still let the default to 48 (TCP_MIN_SND_MSS), for compatibility reasons. Note that TCP_MAXSEG socket option enforces a minimal value of (TCP_MIN_MSS). David Miller increased this minimal value in commit c39508d6f118 ("tcp: Make TCP_MAXSEG minimum more correct.") from 64 to 88. We might in the future merge TCP_MIN_SND_MSS and TCP_MIN_MSS. CVE-2019-11479 -- tcp mss hardcoded to 48 Signed-off-by: Eric Dumazet Suggested-by: Jonathan Looney Acked-by: Neal Cardwell Cc: Yuchung Cheng Cc: Tyler Hicks Cc: Bruce Curtis Cc: Jonathan Lemon Signed-off-by: David S. Miller

netfilter: conntrack: limit sysctl setting for boolean options

2019-04-30T12:18:56Z

We use the zero and one to limit the boolean options setting. After this patch we only set 0 or 1 to boolean options for nf conntrack sysctl. Signed-off-by: Tonghao Zhang Signed-off-by: Pablo Neira Ayuso

ipv6: Add rate limit mask for ICMPv6 messages

2019-04-18T23:58:37Z

To make ICMPv6 closer to ICMPv4, add ratemask parameter. Since the ICMP message types use larger numeric values, a simple bitmask doesn't fit. I use large bitmap. The input and output are the in form of list of ranges. Set the default to rate limit all error messages but Packet Too Big. For Packet Too Big, use ratemask instead of hard-coded. There are functions where icmpv6_xrlim_allow() and icmpv6_global_allow() aren't called. This patch only adds them to icmpv6_echo_reply(). Rate limiting error messages is mandated by RFC 4443 but RFC 4890 says that it is also acceptable to rate limit informational messages. Thus, I removed the current hard-coded behavior of icmpv6_mask_allow() that doesn't rate limit informational messages. v2: Add dummy function proc_do_large_bitmap() if CONFIG_PROC_SYSCTL isn't defined, expand the description in ip-sysctl.txt and remove unnecessary conditional before kfree(). v3: Inline the bitmap instead of dynamically allocated. Still is a pointer to it is needed because of the way proc_do_large_bitmap work. Signed-off-by: Stephen Suryaputra Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2019-04-05T21:14:19Z

Minor comment merge conflict in mlx5. Staging driver has a fixup due to the skb->xmit_more changes in 'net-next', but was removed in 'net'. Signed-off-by: David S. Miller

netns: provide pure entropy for net_hash_mix()

2019-03-29T00:00:45Z

net_hash_mix() currently uses kernel address of a struct net, and is used in many places that could be used to reveal this address to a patient attacker, thus defeating KASLR, for the typical case (initial net namespace, &init_net is not dynamically allocated) I believe the original implementation tried to avoid spending too many cycles in this function, but security comes first. Also provide entropy regardless of CONFIG_NET_NS. Fixes: 0b4419162aa6 ("netns: introduce the net_hash_mix "salt" for hashes") Signed-off-by: Eric Dumazet Reported-by: Amit Klein Reported-by: Benny Pinkas Cc: Pavel Emelyanov Signed-off-by: David S. Miller

inet: switch IP ID generator to siphash

2019-03-27T21:29:26Z

According to Amit Klein and Benny Pinkas, IP ID generation is too weak and might be used by attackers. Even with recent net_hash_mix() fix (netns: provide pure entropy for net_hash_mix()) having 64bit key and Jenkins hash is risky. It is time to switch to siphash and its 128bit keys. Signed-off-by: Eric Dumazet Reported-by: Amit Klein Reported-by: Benny Pinkas Signed-off-by: David S. Miller

ipv6: Add icmp_echo_ignore_anycast for ICMPv6

2019-03-20T23:29:37Z

In addition to icmp_echo_ignore_multicast, there is a need to also prevent responding to pings to anycast addresses for security. Signed-off-by: Stephen Suryaputra Signed-off-by: David S. Miller

ipv6: Add icmp_echo_ignore_multicast support for ICMPv6

2019-03-19T21:29:51Z

IPv4 has icmp_echo_ignore_broadcast to prevent responding to broadcast pings. IPv6 needs a similar mechanism. v1->v2: - Remove NET_IPV6_ICMP_ECHO_IGNORE_MULTICAST. Signed-off-by: Stephen Suryaputra Signed-off-by: David S. Miller

ipv6: icmp: use percpu allocation

2019-02-25T05:57:26Z

Use percpu allocation for the ipv6.icmp_sk. Signed-off-by: Kefeng Wang Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2019-01-29T03:38:33Z

Daniel Borkmann says: ==================== pull-request: bpf-next 2019-01-29 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Teach verifier dead code removal, this also allows for optimizing / removing conditional branches around dead code and to shrink the resulting image. Code store constrained architectures like nfp would have hard time doing this at JIT level, from Jakub. 2) Add JMP32 instructions to BPF ISA in order to allow for optimizing code generation for 32-bit sub-registers. Evaluation shows that this can result in code reduction of ~5-20% compared to 64 bit-only code generation. Also add implementation for most JITs, from Jiong. 3) Add support for __int128 types in BTF which is also needed for vmlinux's BTF conversion to work, from Yonghong. 4) Add a new command to bpftool in order to dump a list of BPF-related parameters from the system or for a specific network device e.g. in terms of available prog/map types or helper functions, from Quentin. 5) Add AF_XDP sock_diag interface for querying sockets from user space which provides information about the RX/TX/fill/completion rings, umem, memory usage etc, from Björn. 6) Add skb context access for skb_shared_info->gso_segs field, from Eric. 7) Add support for testing flow dissector BPF programs by extending existing BPF_PROG_TEST_RUN infrastructure, from Stanislav. 8) Split BPF kselftest's test_verifier into various subgroups of tests in order better deal with merge conflicts in this area, from Jakub. 9) Add support for queue/stack manipulations in bpftool, from Stanislav. 10) Document BTF, from Yonghong. 11) Dump supported ELF section names in libbpf on program load failure, from Taeung. 12) Silence a false positive compiler warning in verifier's BTF handling, from Peter. 13) Fix help string in bpftool's feature probing, from Prashant. 14) Remove duplicate includes in BPF kselftests, from Yue. ==================== Signed-off-by: David S. Miller