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2024-01-17netfilter: bridge: replace physindev with physinif in nf_bridge_infoPavel Tikhomirov1-3/+8
An skb can be added to a neigh->arp_queue while waiting for an arp reply. Where original skb's skb->dev can be different to neigh's neigh->dev. For instance in case of bridging dnated skb from one veth to another, the skb would be added to a neigh->arp_queue of the bridge. As skb->dev can be reset back to nf_bridge->physindev and used, and as there is no explicit mechanism that prevents this physindev from been freed under us (for instance neigh_flush_dev doesn't cleanup skbs from different device's neigh queue) we can crash on e.g. this stack: arp_process neigh_update skb = __skb_dequeue(&neigh->arp_queue) neigh_resolve_output(..., skb) ... br_nf_dev_xmit br_nf_pre_routing_finish_bridge_slow skb->dev = nf_bridge->physindev br_handle_frame_finish Let's use plain ifindex instead of net_device link. To peek into the original net_device we will use dev_get_by_index_rcu(). Thus either we get device and are safe to use it or we don't get it and drop skb. Fixes: c4e70a87d975 ("netfilter: bridge: rename br_netfilter.c to br_netfilter_hooks.c") Suggested-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-01-17netfilter: propagate net to nf_bridge_get_physindevPavel Tikhomirov1-1/+1
This is a preparation patch for replacing physindev with physinif on nf_bridge_info structure. We will use dev_get_by_index_rcu to resolve device, when needed, and it requires net to be available. Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-11-08netfilter: add missing module descriptionsFlorian Westphal4-0/+4
W=1 builds warn on missing MODULE_DESCRIPTION, add them. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-10-18netfilter: xt_mangle: only check verdict part of return valueFlorian Westphal1-4/+5
These checks assume that the caller only returns NF_DROP without any errno embedded in the upper bits. This is fine right now, but followup patches will start to propagate such errors to allow kfree_skb_drop_reason() in the called functions, those would then indicate 'errno << 8 | NF_STOLEN'. To not break things we have to mask those parts out. Signed-off-by: Florian Westphal <fw@strlen.de>
2023-08-30Merge tag 'sysctl-6.6-rc1' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull sysctl updates from Luis Chamberlain: "Long ago we set out to remove the kitchen sink on kernel/sysctl.c arrays and placings sysctls to their own sybsystem or file to help avoid merge conflicts. Matthew Wilcox pointed out though that if we're going to do that we might as well also *save* space while at it and try to remove the extra last sysctl entry added at the end of each array, a sentintel, instead of bloating the kernel by adding a new sentinel with each array moved. Doing that was not so trivial, and has required slowing down the moves of kernel/sysctl.c arrays and measuring the impact on size by each new move. The complex part of the effort to help reduce the size of each sysctl is being done by the patient work of el señor Don Joel Granados. A lot of this is truly painful code refactoring and testing and then trying to measure the savings of each move and removing the sentinels. Although Joel already has code which does most of this work, experience with sysctl moves in the past shows is we need to be careful due to the slew of odd build failures that are possible due to the amount of random Kconfig options sysctls use. To that end Joel's work is split by first addressing the major housekeeping needed to remove the sentinels, which is part of this merge request. The rest of the work to actually remove the sentinels will be done later in future kernel releases. The preliminary math is showing this will all help reduce the overall build time size of the kernel and run time memory consumed by the kernel by about ~64 bytes per array where we are able to remove each sentinel in the future. That also means there is no more bloating the kernel with the extra ~64 bytes per array moved as no new sentinels are created" * tag 'sysctl-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: sysctl: Use ctl_table_size as stopping criteria for list macro sysctl: SIZE_MAX->ARRAY_SIZE in register_net_sysctl vrf: Update to register_net_sysctl_sz networking: Update to register_net_sysctl_sz netfilter: Update to register_net_sysctl_sz ax.25: Update to register_net_sysctl_sz sysctl: Add size to register_net_sysctl function sysctl: Add size arg to __register_sysctl_init sysctl: Add size to register_sysctl sysctl: Add a size arg to __register_sysctl_table sysctl: Add size argument to init_header sysctl: Add ctl_table_size to ctl_table_header sysctl: Use ctl_table_header in list_for_each_table_entry sysctl: Prefer ctl_table_header in proc_sysctl
2023-08-16netfilter: Update to register_net_sysctl_szJoel Granados1-1/+2
Move from register_net_sysctl to register_net_sysctl_sz for all the netfilter related files. Do this while making sure to mirror the NULL assignments with a table_size of zero for the unprivileged users. We need to move to the new function in preparation for when we change SIZE_MAX to ARRAY_SIZE() in the register_net_sysctl macro. Failing to do so would erroneously allow ARRAY_SIZE() to be called on a pointer. We hold off the SIZE_MAX to ARRAY_SIZE change until we have migrated all the relevant net sysctl registering functions to register_net_sysctl_sz in subsequent commits. Acked-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Joel Granados <j.granados@samsung.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-07-29netfilter: defrag: Add glue hooks for enabling/disabling defragDaniel Xu1-0/+11
We want to be able to enable/disable IP packet defrag from core bpf/netfilter code. In other words, execute code from core that could possibly be built as a module. To help avoid symbol resolution errors, use glue hooks that the modules will register callbacks with during module init. Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Reviewed-by: Florian Westphal <fw@strlen.de> Link: https://lore.kernel.org/r/f6a8824052441b72afe5285acedbd634bd3384c1.1689970773.git.dxu@dxuuu.xyz Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-22xtables: move icmp/icmpv6 logic to xt_tcpudpFlorian Westphal1-67/+1
icmp/icmp6 matches are baked into ip(6)_tables.ko. This means that even if iptables-nft is used, a rule like "-p icmp --icmp-type 1" will load the ip(6)tables modules. Move them to xt_tcpdudp.ko instead to avoid this. This will also allow to eventually add kconfig knobs to build kernels that support iptables-nft but not iptables-legacy (old set/getsockopt interface). Signed-off-by: Florian Westphal <fw@strlen.de>
2023-03-06netfilter: tproxy: fix deadlock due to missing BH disableFlorian Westphal1-1/+1
The xtables packet traverser performs an unconditional local_bh_disable(), but the nf_tables evaluation loop does not. Functions that are called from either xtables or nftables must assume that they can be called in process context. inet_twsk_deschedule_put() assumes that no softirq interrupt can occur. If tproxy is used from nf_tables its possible that we'll deadlock trying to aquire a lock already held in process context. Add a small helper that takes care of this and use it. Link: https://lore.kernel.org/netfilter-devel/401bd6ed-314a-a196-1cdc-e13c720cc8f2@balasys.hu/ Fixes: 4ed8eb6570a4 ("netfilter: nf_tables: Add native tproxy support") Reported-and-tested-by: Major Dávid <major.david@balasys.hu> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-02-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nfJakub Kicinski2-3/+8
Pablo Neira Ayuso says: ==================== Netfilter fixes for net 1) Fix broken listing of set elements when table has an owner. 2) Fix conntrack refcount leak in ctnetlink with related conntrack entries, from Hangyu Hua. 3) Fix use-after-free/double-free in ctnetlink conntrack insert path, from Florian Westphal. 4) Fix ip6t_rpfilter with VRF, from Phil Sutter. 5) Fix use-after-free in ebtables reported by syzbot, also from Florian. 6) Use skb->len in xt_length to deal with IPv6 jumbo packets, from Xin Long. 7) Fix NETLINK_LISTEN_ALL_NSID with ctnetlink, from Florian Westphal. 8) Fix memleak in {ip_,ip6_,arp_}tables in ENOMEM error case, from Pavel Tikhomirov. * git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf: netfilter: x_tables: fix percpu counter block leak on error path when creating new netns netfilter: ctnetlink: make event listener tracking global netfilter: xt_length: use skb len to match in length_mt6 netfilter: ebtables: fix table blob use-after-free netfilter: ip6t_rpfilter: Fix regression with VRF interfaces netfilter: conntrack: fix rmmod double-free race netfilter: ctnetlink: fix possible refcount leak in ctnetlink_create_conntrack() netfilter: nf_tables: allow to fetch set elements when table has an owner ==================== Link: https://lore.kernel.org/r/20230222092137.88637-1-pablo@netfilter.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-02-22netfilter: x_tables: fix percpu counter block leak on error path when ↵Pavel Tikhomirov1-0/+4
creating new netns Here is the stack where we allocate percpu counter block: +-< __alloc_percpu +-< xt_percpu_counter_alloc +-< find_check_entry # {arp,ip,ip6}_tables.c +-< translate_table And it can be leaked on this code path: +-> ip6t_register_table +-> translate_table # allocates percpu counter block +-> xt_register_table # fails there is no freeing of the counter block on xt_register_table fail. Note: xt_percpu_counter_free should be called to free it like we do in do_replace through cleanup_entry helper (or in __ip6t_unregister_table). Probability of hitting this error path is low AFAICS (xt_register_table can only return ENOMEM here, as it is not replacing anything, as we are creating new netns, and it is hard to imagine that all previous allocations succeeded and after that one in xt_register_table failed). But it's worth fixing even the rare leak. Fixes: 71ae0dff02d7 ("netfilter: xtables: use percpu rule counters") Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-02-22netfilter: ebtables: fix table blob use-after-freeFlorian Westphal1-2/+1
We are not allowed to return an error at this point. Looking at the code it looks like ret is always 0 at this point, but its not. t = find_table_lock(net, repl->name, &ret, &ebt_mutex); ... this can return a valid table, with ret != 0. This bug causes update of table->private with the new blob, but then frees the blob right away in the caller. Syzbot report: BUG: KASAN: vmalloc-out-of-bounds in __ebt_unregister_table+0xc00/0xcd0 net/bridge/netfilter/ebtables.c:1168 Read of size 4 at addr ffffc90005425000 by task kworker/u4:4/74 Workqueue: netns cleanup_net Call Trace: kasan_report+0xbf/0x1f0 mm/kasan/report.c:517 __ebt_unregister_table+0xc00/0xcd0 net/bridge/netfilter/ebtables.c:1168 ebt_unregister_table+0x35/0x40 net/bridge/netfilter/ebtables.c:1372 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:169 cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:613 ... ip(6)tables appears to be ok (ret should be 0 at this point) but make this more obvious. Fixes: c58dd2dd443c ("netfilter: Can't fail and free after table replacement") Reported-by: syzbot+f61594de72d6705aea03@syzkaller.appspotmail.com Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-02-22netfilter: ip6t_rpfilter: Fix regression with VRF interfacesPhil Sutter1-1/+3
When calling ip6_route_lookup() for the packet arriving on the VRF interface, the result is always the real (slave) interface. Expect this when validating the result. Fixes: acc641ab95b66 ("netfilter: rpfilter/fib: Populate flowic_l3mdev field") Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-02-17netfilter: let reset rules clean out conntrack entriesFlorian Westphal1-0/+1
iptables/nftables support responding to tcp packets with tcp resets. The generated tcp reset packet passes through both output and postrouting netfilter hooks, but conntrack will never see them because the generated skb has its ->nfct pointer copied over from the packet that triggered the reset rule. If the reset rule is used for established connections, this may result in the conntrack entry to be around for a very long time (default timeout is 5 days). One way to avoid this would be to not copy the nf_conn pointer so that the rest packet passes through conntrack too. Problem is that output rules might not have the same conntrack zone setup as the prerouting ones, so its possible that the reset skb won't find the correct entry. Generating a template entry for the skb seems error prone as well. Add an explicit "closing" function that switches a confirmed conntrack entry to closed state and wire this up for tcp. If the entry isn't confirmed, no action is needed because the conntrack entry will never be committed to the table. Reported-by: Russel King <linux@armlinux.org.uk> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-11-15netfilter: nf_tables: Extend nft_expr_ops::dump callback parametersPhil Sutter1-1/+2
Add a 'reset' flag just like with nft_object_ops::dump. This will be useful to reset "anonymous stateful objects", e.g. simple rule counters. No functional change intended. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-11-01net: dropreason: add SKB_DROP_REASON_DUP_FRAGEric Dumazet1-1/+1
This is used to track when a duplicate segment received by various reassembly units is dropped. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-19netfilter: rpfilter/fib: Set ->flowic_uid correctly for user namespaces.Guillaume Nault2-0/+3
Currently netfilter's rpfilter and fib modules implicitely initialise ->flowic_uid with 0. This is normally the root UID. However, this isn't the case in user namespaces, where user ID 0 is mapped to a different kernel UID. By initialising ->flowic_uid with sock_net_uid(), we get the root UID of the user namespace, thus keeping the same behaviour whether or not we're running in a user namepspace. Note, this is similar to commit 8bcfd0925ef1 ("ipv4: add missing initialization for flowi4_uid"), which fixed the rp_filter sysctl. Fixes: 622ec2c9d524 ("net: core: add UID to flows, rules, and routes") Signed-off-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-10-12netfilter: rpfilter/fib: Populate flowic_l3mdev fieldPhil Sutter2-9/+5
Use the introduced field for correct operation with VRF devices instead of conditionally overwriting flowic_oif. This is a partial revert of commit b575b24b8eee3 ("netfilter: Fix rpfilter dropping vrf packets by mistake"), implementing a simpler solution. Signed-off-by: Phil Sutter <phil@nwl.cc> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de>
2022-09-28netfilter: nft_fib: Fix for rpath check with VRF devicesPhil Sutter1-1/+5
Analogous to commit b575b24b8eee3 ("netfilter: Fix rpfilter dropping vrf packets by mistake") but for nftables fib expression: Add special treatment of VRF devices so that typical reverse path filtering via 'fib saddr . iif oif' expression works as expected. Fixes: f6d0cbcf09c50 ("netfilter: nf_tables: add fib expression") Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Florian Westphal <fw@strlen.de>
2022-09-20tcp: Access &tcp_hashinfo via net.Kuniyuki Iwashima2-6/+6
We will soon introduce an optional per-netns ehash. This means we cannot use tcp_hashinfo directly in most places. Instead, access it via net->ipv4.tcp_death_row.hashinfo. The access will be valid only while initialising tcp_hashinfo itself and creating/destroying each netns. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-24netfilter: nf_defrag_ipv6: allow nf_conntrack_frag6_high_thresh increasesEric Dumazet1-1/+0
Currently, net.netfilter.nf_conntrack_frag6_high_thresh can only be lowered. I found this issue while investigating a probable kernel issue causing flakes in tools/testing/selftests/net/ip_defrag.sh In particular, these sysctl changes were ignored: ip netns exec "${NETNS}" sysctl -w net.netfilter.nf_conntrack_frag6_high_thresh=9000000 >/dev/null 2>&1 ip netns exec "${NETNS}" sysctl -w net.netfilter.nf_conntrack_frag6_low_thresh=7000000 >/dev/null 2>&1 This change is inline with commit 836196239298 ("net/ipfrag: let ip[6]frag_high_thresh in ns be higher than in init_net") Fixes: 8db3d41569bb ("netfilter: nf_defrag_ipv6: use net_generic infra") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-05-13netfilter: conntrack: skip verification of zero UDP checksumKevin Mitchell1-2/+2
The checksum is optional for UDP packets. However nf_reject would previously require a valid checksum to elicit a response such as ICMP_DEST_UNREACH. Add some logic to nf_reject_verify_csum to determine if a UDP packet has a zero checksum and should therefore not be verified. Signed-off-by: Kevin Mitchell <kevmitch@arista.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-04-11netfilter: nft_fib: reverse path filter for policy-based routing on iifPablo Neira Ayuso1-0/+4
If policy-based routing using the iif selector is used, then the fib expression fails to look up for the reverse path from the prerouting hook because the input interface cannot be inferred. In order to support this scenario, extend the fib expression to allow to use after the route lookup, from the forward hook. This patch also adds support for the input hook for usability reasons. Since the prerouting hook cannot be used for the scenario described above, users need two rules: one for the forward chain and another rule for the input chain to check for the reverse path check for locally targeted traffic. Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-03-20netfilter: nft_fib: add reduce supportFlorian Westphal1-0/+2
The fib expression stores to a register, so we can't add empty stub. Check that the register that is being written is in fact redundant. In most cases, this is expected to cancel tracking as re-use is unlikely. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-03-20netfilter: nf_tables: do not reduce read-only expressionsPablo Neira Ayuso2-0/+2
Skip register tracking for expressions that perform read-only operations on the registers. Define and use a cookie pointer NFT_REDUCE_READONLY to avoid defining stubs for these expressions. This patch re-enables register tracking which was disabled in ed5f85d42290 ("netfilter: nf_tables: disable register tracking"). Follow up patches add remaining register tracking for existing expressions. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-03-03net: ipv6: Handle delivery_time in ipv6 defragMartin KaFai Lau1-0/+1
A latter patch will postpone the delivery_time clearing until the stack knows the skb is being delivered locally (i.e. calling skb_clear_delivery_time() at ip_local_deliver_finish() for IPv4 and at ip6_input_finish() for IPv6). That will allow other kernel forwarding path (e.g. ip[6]_forward) to keep the delivery_time also. A very similar IPv6 defrag codes have been duplicated in multiple places: regular IPv6, nf_conntrack, and 6lowpan. Unlike the IPv4 defrag which is done before ip_local_deliver_finish(), the regular IPv6 defrag is done after ip6_input_finish(). Thus, no change should be needed in the regular IPv6 defrag logic because skb_clear_delivery_time() should have been called. 6lowpan also does not need special handling on delivery_time because it is a non-inet packet_type. However, cf_conntrack has a case in NF_INET_PRE_ROUTING that needs to do the IPv6 defrag earlier. Thus, it needs to save the mono_delivery_time bit in the inet_frag_queue which is similar to how it is handled in the previous patch for the IPv4 defrag. This patch chooses to do it consistently and stores the mono_delivery_time in the inet_frag_queue for all cases such that it will be easier for the future refactoring effort on the IPv6 reasm code. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-27netfilter: Remove flowtable relicsGeert Uytterhoeven3-7/+0
NF_FLOW_TABLE_IPV4 and NF_FLOW_TABLE_IPV6 are invisble, selected by nothing (so they can no longer be enabled), and their last real users have been removed (nf_flow_table_ipv6.c is empty). Clean up the leftovers. Fixes: c42ba4290b2147aa ("netfilter: flowtable: remove ipv4/ipv6 modules") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-12-23netfilter: flowtable: remove ipv4/ipv6 modulesFlorian Westphal2-44/+2
Just place the structs and registration in the inet module. nf_flow_table_ipv6, nf_flow_table_ipv4 and nf_flow_table_inet share same module dependencies: nf_flow_table, nf_tables. before: text data bss dec hex filename 2278 1480 0 3758 eae nf_flow_table_inet.ko 1159 1352 0 2511 9cf nf_flow_table_ipv6.ko 1154 1352 0 2506 9ca nf_flow_table_ipv4.ko after: 2369 1672 0 4041 fc9 nf_flow_table_inet.ko Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-10-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller1-42/+6
Lots of simnple overlapping additions. With a build fix from Stephen Rothwell. Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller6-44/+14
Pablo Neira Ayuso says: ==================== Netfilter/IPVS updates for net-next The following patchset contains Netfilter/IPVS for net-next: 1) Add new run_estimation toggle to IPVS to stop the estimation_timer logic, from Dust Li. 2) Relax superfluous dynset check on NFT_SET_TIMEOUT. 3) Add egress hook, from Lukas Wunner. 4) Nowadays, almost all hook functions in x_table land just call the hook evaluation loop. Remove remaining hook wrappers from iptables and IPVS. From Florian Westphal. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-15netfilter: ip6t_rt: fix rt0_hdr parsing in rt_mt6Xin Long1-42/+6
In rt_mt6(), when it's a nonlinear skb, the 1st skb_header_pointer() only copies sizeof(struct ipv6_rt_hdr) to _route that rh points to. The access by ((const struct rt0_hdr *)rh)->reserved will overflow the buffer. So this access should be moved below the 2nd call to skb_header_pointer(). Besides, after the 2nd skb_header_pointer(), its return value should also be checked, othersize, *rp may cause null-pointer-ref. v1->v2: - clean up some old debugging log. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-10-15netfilter: ip6tables: allow use of ip6t_do_table as hookfnFlorian Westphal6-44/+14
This is possible now that the xt_table structure is passed via *priv. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-09-28netfilter: conntrack: fix boot failure with nf_conntrack.enable_hooks=1Florian Westphal2-17/+10
This is a revert of 7b1957b049 ("netfilter: nf_defrag_ipv4: use net_generic infra") and a partial revert of 8b0adbe3e3 ("netfilter: nf_defrag_ipv6: use net_generic infra"). If conntrack is builtin and kernel is booted with: nf_conntrack.enable_hooks=1 .... kernel will fail to boot due to a NULL deref in nf_defrag_ipv4_enable(): Its called before the ipv4 defrag initcall is made, so net_generic() returns NULL. To resolve this, move the user refcount back to struct net so calls to those functions are possible even before their initcalls have run. Fixes: 7b1957b04956 ("netfilter: nf_defrag_ipv4: use net_generic infra") Fixes: 8b0adbe3e38d ("netfilter: nf_defrag_ipv6: use net_generic infra"). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-09-15netfilter: ip6_tables: zero-initialize fragment offsetJeremy Sowden1-0/+1
ip6tables only sets the `IP6T_F_PROTO` flag on a rule if a protocol is specified (`-p tcp`, for example). However, if the flag is not set, `ip6_packet_match` doesn't call `ipv6_find_hdr` for the skb, in which case the fragment offset is left uninitialized and a garbage value is passed to each matcher. Signed-off-by: Jeremy Sowden <jeremy@azazel.net> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-09-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nfJakub Kicinski1-3/+1
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 <kuba@kernel.org>
2021-09-03netfilter: socket: icmp6: fix use-after-scopeBenjamin Hesmans1-3/+1
Bug reported by KASAN: BUG: KASAN: use-after-scope in inet6_ehashfn (net/ipv6/inet6_hashtables.c:40) Call Trace: (...) inet6_ehashfn (net/ipv6/inet6_hashtables.c:40) (...) nf_sk_lookup_slow_v6 (net/ipv6/netfilter/nf_socket_ipv6.c:91 net/ipv6/netfilter/nf_socket_ipv6.c:146) It seems that this bug has already been fixed by Eric Dumazet in the past in: commit 78296c97ca1f ("netfilter: xt_socket: fix a stack corruption bug") But a variant of the same issue has been introduced in commit d64d80a2cde9 ("netfilter: x_tables: don't extract flow keys on early demuxed sks in socket match") `daddr` and `saddr` potentially hold a reference to ipv6_var that is no longer in scope when the call to `nf_socket_get_sock_v6` is made. Fixes: d64d80a2cde9 ("netfilter: x_tables: don't extract flow keys on early demuxed sks in socket match") Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Benjamin Hesmans <benjamin.hesmans@tessares.net> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-09netfilter: x_tables: never register tables by defaultFlorian Westphal5-51/+56
For historical reasons x_tables still register tables by default in the initial namespace. Only newly created net namespaces add the hook on demand. This means that the init_net always pays hook cost, even if no filtering rules are added (e.g. only used inside a single netns). Note that the hooks are added even when 'iptables -L' is called. This is because there is no way to tell 'iptables -A' and 'iptables -L' apart at kernel level. The only solution would be to register the table, but delay hook registration until the first rule gets added (or policy gets changed). That however means that counters are not hooked either, so 'iptables -L' would always show 0-counters even when traffic is flowing which might be unexpected. This keeps table and hook registration consistent with what is already done in non-init netns: first iptables(-save) invocation registers both table and hooks. This applies the same solution adopted for ebtables. All tables register a template that contains the l3 family, the name and a constructor function that is called when the initial table has to be added. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-06-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-4/+18
Trivial conflicts in net/can/isotp.c and tools/testing/selftests/net/mptcp/mptcp_connect.sh scaled_ppm_to_ppb() was moved from drivers/ptp/ptp_clock.c to include/linux/ptp_clock_kernel.h in -next so re-apply the fix there. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-06-09netfilter: nft_fib_ipv6: skip ipv6 packets from any to link-localFlorian Westphal1-4/+18
The ip6tables rpfilter match has an extra check to skip packets with "::" source address. Extend this to ipv6 fib expression. Else ipv6 duplicate address detection packets will fail rpf route check -- lookup returns -ENETUNREACH. While at it, extend the prerouting check to also cover the ingress hook. Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1543 Fixes: f6d0cbcf09c5 ("netfilter: nf_tables: add fib expression") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-05-29netfilter: nf_tables: add and use nft_sk helperFlorian Westphal1-1/+1
This allows to change storage placement later on without changing readers. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-05-29netfilter: x_tables: reduce xt_action_param by 8 byteFlorian Westphal1-1/+1
The fragment offset in ipv4/ipv6 is a 16bit field, so use u16 instead of unsigned int. On 64bit: 40 bytes to 32 bytes. By extension this also reduces nft_pktinfo (56 to 48 byte). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26netfilter: allow to turn off xtables compat layerFlorian Westphal1-8/+8
The compat layer needs to parse untrusted input (the ruleset) to translate it to a 64bit compatible format. We had a number of bugs in this department in the past, so allow users to turn this feature off. Add CONFIG_NETFILTER_XTABLES_COMPAT kconfig knob and make it default to y to keep existing behaviour. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26netfilter: ip6_tables: pass table pointer via nf_hook_opsFlorian Westphal6-54/+61
Same patch as the ip_tables one: removal of all accesses to ip6_tables xt_table pointers. After this patch the struct net xt_table anchors can be removed. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26netfilter: xt_nat: pass table to hookfnFlorian Westphal1-10/+35
This changes how ip(6)table nat passes the ruleset/table to the evaluation loop. At the moment, it will fetch the table from struct net. This change stores the table in the hook_ops 'priv' argument instead. This requires to duplicate the hook_ops for each netns, so they can store the (per-net) xt_table structure. The dupliated nat hook_ops get stored in net_generic data area. They are free'd in the namespace exit path. This is a pre-requisite to remove the xt_table/ruleset pointers from struct net. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26netfilter: x_tables: remove paranoia testsFlorian Westphal5-15/+0
No need for these. There is only one caller, the xtables core, when the table is registered for the first time with a particular network namespace. After ->table_init() call, the table is linked into the tables[af] list, so next call to that function will skip the ->table_init(). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26netfilter: ip6tables: unregister the tables by nameFlorian Westphal6-33/+22
Same as the previous patch, but for ip6tables. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26netfilter: x_tables: remove ipt_unregister_tableFlorian Westphal2-10/+1
Its the same function as ipt_unregister_table_exit. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26netfilter: disable defrag once its no longer neededFlorian Westphal1-6/+23
When I changed defrag hooks to no longer get registered by default I intentionally made it so that registration can only be un-done by unloading the nf_defrag_ipv4/6 module. In hindsight this was too conservative; there is no reason to keep defrag on while there is no feature dependency anymore. Moreover, this won't work if user isn't allowed to remove nf_defrag module. This adds the disable() functions for both ipv4 and ipv6 and calls them from conntrack, TPROXY and the xtables socket module. ipvs isn't converted here, it will behave as before this patch and will need module removal. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-0/+2
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c - keep the ZC code, drop the code related to reinit net/bridge/netfilter/ebtables.c - fix build after move to net_generic Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-04-13netfilter: x_tables: fix compat match/target pad out-of-bound writeFlorian Westphal1-0/+2
xt_compat_match/target_from_user doesn't check that zeroing the area to start of next rule won't write past end of allocated ruleset blob. Remove this code and zero the entire blob beforehand. Reported-by: syzbot+cfc0247ac173f597aaaa@syzkaller.appspotmail.com Reported-by: Andy Nguyen <theflow@google.com> Fixes: 9fa492cdc160c ("[NETFILTER]: x_tables: simplify compat API") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>