kernel/linux.git/include/net/netns, branch v4.19.77

tcp: add tcp_min_snd_mss sysctl

2019-06-17T17:51:56+00:00

commit 5f3e2bf008c2221478101ee72f5cb4654b9fc363 upstream. 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 Signed-off-by: Greg Kroah-Hartman

inet: switch IP ID generator to siphash

2019-06-04T06:02:30+00:00

[ Upstream commit df453700e8d81b1bdafdf684365ee2b9431fb702 ] 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 Signed-off-by: Greg Kroah-Hartman

netns: provide pure entropy for net_hash_mix()

2019-04-17T06:38:40+00:00

[ Upstream commit 355b98553789b646ed97ad801a619ff898471b92 ] 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 Signed-off-by: Sasha Levin

ipv6: Add icmp_echo_ignore_all support for ICMPv6

2018-08-13T15:42:25+00:00

Preventing the kernel from responding to ICMP Echo Requests messages can be useful in several ways. The sysctl parameter 'icmp_echo_ignore_all' can be used to prevent the kernel from responding to IPv4 ICMP echo requests. For IPv6 pings, such a sysctl kernel parameter did not exist. Add the ability to prevent the kernel from responding to IPv6 ICMP echo requests through the use of the following sysctl parameter : /proc/sys/net/ipv6/icmp/echo_ignore_all. Update the documentation to reflect this change. Signed-off-by: Virgile Jarry Signed-off-by: David S. Miller

net: ipv4: Control SKB reprioritization after forwarding

2018-08-01T16:52:30+00:00

After IPv4 packets are forwarded, the priority of the corresponding SKB is updated according to the TOS field of IPv4 header. This overrides any prioritization done earlier by e.g. an skbedit action or ingress-qos-map defined at a vlan device. Such overriding may not always be desirable. Even if the packet ends up being routed, which implies this is an L3 network node, an administrator may wish to preserve whatever prioritization was done earlier on in the pipeline. Therefore introduce a sysctl that controls this behavior. Keep the default value at 1 to maintain backward-compatible behavior. Signed-off-by: Petr Machata Reviewed-by: Ido Schimmel Signed-off-by: David S. Miller

netfilter: nf_tables: use dedicated mutex to guard transactions

2018-07-18T09:26:48+00:00

Continue to use nftnl subsys mutex to protect (un)registration of hook types, expressions and so on, but force batch operations to do their own locking. This allows distinct net namespaces to perform transactions in parallel. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

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

2018-07-03T01:29:26+00:00

Simple overlapping changes in stmmac driver. Adjust skb_gro_flush_final_remcsum function signature to make GRO list changes in net-next, as per Stephen Rothwell's example merge resolution. Signed-off-by: David S. Miller

netns: get more entropy from net_hash_mix()

2018-06-23T01:59:56+00:00

struct net are effectively allocated from order-1 pages on x86, with one object per slab, meaning that the 13 low order bits of their addresses are zero. Once shifted by L1_CACHE_SHIFT, this leaves 7 zero-bits, meaning that net_hash_mix() does not help spreading objects on various hash tables. For example, TCP listen table has 32 buckets, meaning that all netns use the same bucket for port 80 or port 443. Signed-off-by: Eric Dumazet Reported-by: Maciej Żenczykowski Signed-off-by: David S. Miller

netfilter: ipv6: nf_defrag: reduce struct net memory waste

2018-06-18T12:13:25+00:00

It is a waste of memory to use a full "struct netns_sysctl_ipv6" while only one pointer is really used, considering netns_sysctl_ipv6 keeps growing. Also, since "struct netns_frags" has cache line alignment, it is better to move the frags_hdr pointer outside, otherwise we spend a full cache line for this pointer. This saves 192 bytes of memory per netns. Fixes: c038a767cd69 ("ipv6: add a new namespace for nf_conntrack_reasm") Signed-off-by: Eric Dumazet Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: fix chain dependency validation

2018-06-01T07:46:22+00:00

The following ruleset: add table ip filter add chain ip filter input { type filter hook input priority 4; } add chain ip filter ap add rule ip filter input jump ap add rule ip filter ap masquerade results in a panic, because the masquerade extension should be rejected from the filter chain. The existing validation is missing a chain dependency check when the rule is added to the non-base chain. This patch fixes the problem by walking down the rules from the basechains, searching for either immediate or lookup expressions, then jumping to non-base chains and again walking down the rules to perform the expression validation, so we make sure the full ruleset graph is validated. This is done only once from the commit phase, in case of problem, we abort the transaction and perform fine grain validation for error reporting. This patch requires 003087911af2 ("netfilter: nfnetlink: allow commit to fail") to achieve this behaviour. This patch also adds a cleanup callback to nfnl batch interface to reset the validate state from the exit path. As a result of this patch, nf_tables_check_loops() doesn't use ->validate to check for loops, instead it just checks for immediate expressions. Reported-by: Taehee Yoo Signed-off-by: Pablo Neira Ayuso