kernel/linux.git/include/linux/netfilter, branch v6.1.70

netfilter: handle the connecting collision properly in nf_conntrack_proto_sctp

2023-10-10T20:00:43+00:00

[ Upstream commit 8e56b063c86569e51eed1c5681ce6361fa97fc7a ] In Scenario A and B below, as the delayed INIT_ACK always changes the peer vtag, SCTP ct with the incorrect vtag may cause packet loss. Scenario A: INIT_ACK is delayed until the peer receives its own INIT_ACK 192.168.1.2 > 192.168.1.1: [INIT] [init tag: 1328086772] 192.168.1.1 > 192.168.1.2: [INIT] [init tag: 1414468151] 192.168.1.2 > 192.168.1.1: [INIT ACK] [init tag: 1328086772] 192.168.1.1 > 192.168.1.2: [INIT ACK] [init tag: 1650211246] * 192.168.1.2 > 192.168.1.1: [COOKIE ECHO] 192.168.1.1 > 192.168.1.2: [COOKIE ECHO] 192.168.1.2 > 192.168.1.1: [COOKIE ACK] Scenario B: INIT_ACK is delayed until the peer completes its own handshake 192.168.1.2 > 192.168.1.1: sctp (1) [INIT] [init tag: 3922216408] 192.168.1.1 > 192.168.1.2: sctp (1) [INIT] [init tag: 144230885] 192.168.1.2 > 192.168.1.1: sctp (1) [INIT ACK] [init tag: 3922216408] 192.168.1.1 > 192.168.1.2: sctp (1) [COOKIE ECHO] 192.168.1.2 > 192.168.1.1: sctp (1) [COOKIE ACK] 192.168.1.1 > 192.168.1.2: sctp (1) [INIT ACK] [init tag: 3914796021] * This patch fixes it as below: In SCTP_CID_INIT processing: - clear ct->proto.sctp.init[!dir] if ct->proto.sctp.init[dir] && ct->proto.sctp.init[!dir]. (Scenario E) - set ct->proto.sctp.init[dir]. In SCTP_CID_INIT_ACK processing: - drop it if !ct->proto.sctp.init[!dir] && ct->proto.sctp.vtag[!dir] && ct->proto.sctp.vtag[!dir] != ih->init_tag. (Scenario B, Scenario C) - drop it if ct->proto.sctp.init[dir] && ct->proto.sctp.init[!dir] && ct->proto.sctp.vtag[!dir] != ih->init_tag. (Scenario A) In SCTP_CID_COOKIE_ACK processing: - clear ct->proto.sctp.init[dir] and ct->proto.sctp.init[!dir]. (Scenario D) Also, it's important to allow the ct state to move forward with cookie_echo and cookie_ack from the opposite dir for the collision scenarios. There are also other Scenarios where it should allow the packet through, addressed by the processing above: Scenario C: new CT is created by INIT_ACK. Scenario D: start INIT on the existing ESTABLISHED ct. Scenario E: start INIT after the old collision on the existing ESTABLISHED ct. 192.168.1.2 > 192.168.1.1: sctp (1) [INIT] [init tag: 3922216408] 192.168.1.1 > 192.168.1.2: sctp (1) [INIT] [init tag: 144230885] (both side are stopped, then start new connection again in hours) 192.168.1.2 > 192.168.1.1: sctp (1) [INIT] [init tag: 242308742] Fixes: 9fb9cbb1082d ("[NETFILTER]: Add nf_conntrack subsystem.") Signed-off-by: Xin Long Signed-off-by: Florian Westphal Signed-off-by: Sasha Levin

netfilter: nf_tables: don't write table validation state without mutex

2023-05-11T14:03:26+00:00

[ Upstream commit 9a32e9850686599ed194ccdceb6cd3dd56b2d9b9 ] The ->cleanup callback needs to be removed, this doesn't work anymore as the transaction mutex is already released in the ->abort function. Just do it after a successful validation pass, this either happens from commit or abort phases where transaction mutex is held. Fixes: f102d66b335a ("netfilter: nf_tables: use dedicated mutex to guard transactions") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: ipset: Rework long task execution when adding/deleting entries

2023-01-12T11:02:26+00:00

[ Upstream commit 5e29dc36bd5e2166b834ceb19990d9e68a734d7d ] When adding/deleting large number of elements in one step in ipset, it can take a reasonable amount of time and can result in soft lockup errors. The patch 5f7b51bf09ba ("netfilter: ipset: Limit the maximal range of consecutive elements to add/delete") tried to fix it by limiting the max elements to process at all. However it was not enough, it is still possible that we get hung tasks. Lowering the limit is not reasonable, so the approach in this patch is as follows: rely on the method used at resizing sets and save the state when we reach a smaller internal batch limit, unlock/lock and proceed from the saved state. Thus we can avoid long continuous tasks and at the same time removed the limit to add/delete large number of elements in one step. The nfnl mutex is held during the whole operation which prevents one to issue other ipset commands in parallel. Fixes: 5f7b51bf09ba ("netfilter: ipset: Limit the maximal range of consecutive elements to add/delete") Reported-by: syzbot+9204e7399656300bf271@syzkaller.appspotmail.com Signed-off-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: h323: merge nat hook pointers into one

2022-07-11T14:25:16+00:00

sparse complains about incorrect rcu usage. Code uses the correct rcu access primitives, but the function pointers lack rcu annotations. Collapse all of them into a single structure, then annotate the pointer. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: nf_conntrack: add missing __rcu annotations

2022-07-11T14:25:15+00:00

Access to the hook pointers use correct helpers but the pointers lack the needed __rcu annotation. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: conntrack: pptp: use single option structure

2022-02-04T05:30:28+00:00

Instead of exposing the four hooks individually use a sinle hook ops structure. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: conntrack: avoid useless indirection during conntrack destruction

2022-01-09T22:30:13+00:00

nf_ct_put() results in a usesless indirection: nf_ct_put -> nf_conntrack_put -> nf_conntrack_destroy -> rcu readlock + indirect call of ct_hooks->destroy(). There are two _put helpers: nf_ct_put and nf_conntrack_put. The latter is what should be used in code that MUST NOT cause a linker dependency on the conntrack module (e.g. calls from core network stack). Everyone else should call nf_ct_put() instead. A followup patch will convert a few nf_conntrack_put() calls to nf_ct_put(), in particular from modules that already have a conntrack dependency such as act_ct or even nf_conntrack itself. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: conntrack: convert to refcount_t api

2022-01-09T22:30:13+00:00

Convert nf_conn reference counting from atomic_t to refcount_t based api. refcount_t api provides more runtime sanity checks and will warn on certain constructs, e.g. refcount_inc() on a zero reference count, which usually indicates use-after-free. For this reason template allocation is changed to init the refcount to 1, the subsequenct add operations are removed. Likewise, init_conntrack() is changed to set the initial refcount to 1 instead refcount_inc(). This is safe because the new entry is not (yet) visible to other cpus. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf

2021-09-03T23:20:37+00:00

Pablo Neira Ayuso says: ==================== Netfilter fixes for net 1) Protect nft_ct template with global mutex, from Pavel Skripkin. 2) Two recent commits switched inet rt and nexthop exception hashes from jhash to siphash. If those two spots are problematic then conntrack is affected as well, so switch voer to siphash too. While at it, add a hard upper limit on chain lengths and reject insertion if this is hit. Patches from Florian Westphal. 3) Fix use-after-scope in nf_socket_ipv6 reported by KASAN, from Benjamin Hesmans. * git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf: netfilter: socket: icmp6: fix use-after-scope netfilter: refuse insertion if chain has grown too large netfilter: conntrack: switch to siphash netfilter: conntrack: sanitize table size default settings netfilter: nft_ct: protect nft_ct_pcpu_template_refcnt with mutex ==================== Link: https://lore.kernel.org/r/20210903163020.13741-1-pablo@netfilter.org Signed-off-by: Jakub Kicinski

netfilter: refuse insertion if chain has grown too large

2021-08-30T09:52:21+00:00

Also add a stat counter for this that gets exported both via old /proc interface and ctnetlink. Assuming the old default size of 16536 buckets and max hash occupancy of 64k, this results in 128k insertions (origin+reply), so ~8 entries per chain on average. The revised settings in this series will result in about two entries per bucket on average. This allows a hard-limit ceiling of 64. This is not tunable at the moment, but its possible to either increase nf_conntrack_buckets or decrease nf_conntrack_max to reduce average lengths. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso