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2024-05-06netfilter: nf_tables: remove NETDEV_CHANGENAME from netdev chain event handlerPablo Neira Ayuso1-5/+1
Originally, device name used to be stored in the basechain, but it is not the case anymore. Remove check for NETDEV_CHANGENAME. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-04-25netfilter: nf_tables: honor table dormant flag from netdev release event pathPablo Neira Ayuso1-1/+3
Check for table dormant flag otherwise netdev release event path tries to unregister an already unregistered hook. [524854.857999] ------------[ cut here ]------------ [524854.858010] WARNING: CPU: 0 PID: 3386599 at net/netfilter/core.c:501 __nf_unregister_net_hook+0x21a/0x260 [...] [524854.858848] CPU: 0 PID: 3386599 Comm: kworker/u32:2 Not tainted 6.9.0-rc3+ #365 [524854.858869] Workqueue: netns cleanup_net [524854.858886] RIP: 0010:__nf_unregister_net_hook+0x21a/0x260 [524854.858903] Code: 24 e8 aa 73 83 ff 48 63 43 1c 83 f8 01 0f 85 3d ff ff ff e8 98 d1 f0 ff 48 8b 3c 24 e8 8f 73 83 ff 48 63 43 1c e9 26 ff ff ff <0f> 0b 48 83 c4 18 48 c7 c7 00 68 e9 82 5b 5d 41 5c 41 5d 41 5e 41 [524854.858914] RSP: 0018:ffff8881e36d79e0 EFLAGS: 00010246 [524854.858926] RAX: 0000000000000000 RBX: ffff8881339ae790 RCX: ffffffff81ba524a [524854.858936] RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff8881c8a16438 [524854.858945] RBP: ffff8881c8a16438 R08: 0000000000000001 R09: ffffed103c6daf34 [524854.858954] R10: ffff8881e36d79a7 R11: 0000000000000000 R12: 0000000000000005 [524854.858962] R13: ffff8881c8a16000 R14: 0000000000000000 R15: ffff8881351b5a00 [524854.858971] FS: 0000000000000000(0000) GS:ffff888390800000(0000) knlGS:0000000000000000 [524854.858982] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [524854.858991] CR2: 00007fc9be0f16f4 CR3: 00000001437cc004 CR4: 00000000001706f0 [524854.859000] Call Trace: [524854.859006] <TASK> [524854.859013] ? __warn+0x9f/0x1a0 [524854.859027] ? __nf_unregister_net_hook+0x21a/0x260 [524854.859044] ? report_bug+0x1b1/0x1e0 [524854.859060] ? handle_bug+0x3c/0x70 [524854.859071] ? exc_invalid_op+0x17/0x40 [524854.859083] ? asm_exc_invalid_op+0x1a/0x20 [524854.859100] ? __nf_unregister_net_hook+0x6a/0x260 [524854.859116] ? __nf_unregister_net_hook+0x21a/0x260 [524854.859135] nf_tables_netdev_event+0x337/0x390 [nf_tables] [524854.859304] ? __pfx_nf_tables_netdev_event+0x10/0x10 [nf_tables] [524854.859461] ? packet_notifier+0xb3/0x360 [524854.859476] ? _raw_spin_unlock_irqrestore+0x11/0x40 [524854.859489] ? dcbnl_netdevice_event+0x35/0x140 [524854.859507] ? __pfx_nf_tables_netdev_event+0x10/0x10 [nf_tables] [524854.859661] notifier_call_chain+0x7d/0x140 [524854.859677] unregister_netdevice_many_notify+0x5e1/0xae0 Fixes: d54725cd11a5 ("netfilter: nf_tables: support for multiple devices per netdev hook") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-01-24netfilter: nft_chain_filter: handle NETDEV_UNREGISTER for inet/ingress basechainPablo Neira Ayuso1-2/+9
Remove netdevice from inet/ingress basechain in case NETDEV_UNREGISTER event is reported, otherwise a stale reference to netdevice remains in the hook list. Fixes: 60a3815da702 ("netfilter: add inet ingress support") Cc: stable@vger.kernel.org Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-05-10netfilter: nf_tables: always release netdev hooks from notifierFlorian Westphal1-3/+6
This reverts "netfilter: nf_tables: skip netdev events generated on netns removal". The problem is that when a veth device is released, the veth release callback will also queue the peer netns device for removal. Its possible that the peer netns is also slated for removal. In this case, the device memory is already released before the pre_exit hook of the peer netns runs: BUG: KASAN: slab-use-after-free in nf_hook_entry_head+0x1b8/0x1d0 Read of size 8 at addr ffff88812c0124f0 by task kworker/u8:1/45 Workqueue: netns cleanup_net Call Trace: nf_hook_entry_head+0x1b8/0x1d0 __nf_unregister_net_hook+0x76/0x510 nft_netdev_unregister_hooks+0xa0/0x220 __nft_release_hook+0x184/0x490 nf_tables_pre_exit_net+0x12f/0x1b0 .. Order is: 1. First netns is released, veth_dellink() queues peer netns device for removal 2. peer netns is queued for removal 3. peer netns device is released, unreg event is triggered 4. unreg event is ignored because netns is going down 5. pre_exit hook calls nft_netdev_unregister_hooks but device memory might be free'd already. Fixes: 68a3765c659f ("netfilter: nf_tables: skip netdev events generated on netns removal") 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. Miller1-6/+3
Lots of simnple overlapping additions. With a build fix from Stephen Rothwell. Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-14netfilter: Introduce egress hookLukas Wunner1-1/+3
Support classifying packets with netfilter on egress to satisfy user requirements such as: * outbound security policies for containers (Laura) * filtering and mangling intra-node Direct Server Return (DSR) traffic on a load balancer (Laura) * filtering locally generated traffic coming in through AF_PACKET, such as local ARP traffic generated for clustering purposes or DHCP (Laura; the AF_PACKET plumbing is contained in a follow-up commit) * L2 filtering from ingress and egress for AVB (Audio Video Bridging) and gPTP with nftables (Pablo) * in the future: in-kernel NAT64/NAT46 (Pablo) The egress hook introduced herein complements the ingress hook added by commit e687ad60af09 ("netfilter: add netfilter ingress hook after handle_ing() under unique static key"). A patch for nftables to hook up egress rules from user space has been submitted separately, so users may immediately take advantage of the feature. Alternatively or in addition to netfilter, packets can be classified with traffic control (tc). On ingress, packets are classified first by tc, then by netfilter. On egress, the order is reversed for symmetry. Conceptually, tc and netfilter can be thought of as layers, with netfilter layered above tc. Traffic control is capable of redirecting packets to another interface (man 8 tc-mirred). E.g., an ingress packet may be redirected from the host namespace to a container via a veth connection: tc ingress (host) -> tc egress (veth host) -> tc ingress (veth container) In this case, netfilter egress classifying is not performed when leaving the host namespace! That's because the packet is still on the tc layer. If tc redirects the packet to a physical interface in the host namespace such that it leaves the system, the packet is never subjected to netfilter egress classifying. That is only logical since it hasn't passed through netfilter ingress classifying either. Packets can alternatively be redirected at the netfilter layer using nft fwd. Such a packet *is* subjected to netfilter egress classifying since it has reached the netfilter layer. Internally, the skb->nf_skip_egress flag controls whether netfilter is invoked on egress by __dev_queue_xmit(). Because __dev_queue_xmit() may be called recursively by tunnel drivers such as vxlan, the flag is reverted to false after sch_handle_egress(). This ensures that netfilter is applied both on the overlay and underlying network. Interaction between tc and netfilter is possible by setting and querying skb->mark. If netfilter egress classifying is not enabled on any interface, it is patched out of the data path by way of a static_key and doesn't make a performance difference that is discernible from noise: Before: 1537 1538 1538 1537 1538 1537 Mb/sec After: 1536 1534 1539 1539 1539 1540 Mb/sec Before + tc accept: 1418 1418 1418 1419 1419 1418 Mb/sec After + tc accept: 1419 1424 1418 1419 1422 1420 Mb/sec Before + tc drop: 1620 1619 1619 1619 1620 1620 Mb/sec After + tc drop: 1616 1624 1625 1624 1622 1619 Mb/sec When netfilter egress classifying is enabled on at least one interface, a minimal performance penalty is incurred for every egress packet, even if the interface it's transmitted over doesn't have any netfilter egress rules configured. That is caused by checking dev->nf_hooks_egress against NULL. Measurements were performed on a Core i7-3615QM. Commands to reproduce: ip link add dev foo type dummy ip link set dev foo up modprobe pktgen echo "add_device foo" > /proc/net/pktgen/kpktgend_3 samples/pktgen/pktgen_bench_xmit_mode_queue_xmit.sh -i foo -n 400000000 -m "11:11:11:11:11:11" -d 1.1.1.1 Accept all traffic with tc: tc qdisc add dev foo clsact tc filter add dev foo egress bpf da bytecode '1,6 0 0 0,' Drop all traffic with tc: tc qdisc add dev foo clsact tc filter add dev foo egress bpf da bytecode '1,6 0 0 2,' Apply this patch when measuring packet drops to avoid errors in dmesg: https://lore.kernel.org/netdev/a73dda33-57f4-95d8-ea51-ed483abd6a7a@iogearbox.net/ Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: Laura García Liébana <nevola@gmail.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Thomas Graf <tgraf@suug.ch> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-10-07netfilter: nf_tables: skip netdev events generated on netns removalFlorian Westphal1-6/+3
syzbot reported following (harmless) WARN: WARNING: CPU: 1 PID: 2648 at net/netfilter/core.c:468 nft_netdev_unregister_hooks net/netfilter/nf_tables_api.c:230 [inline] nf_tables_unregister_hook include/net/netfilter/nf_tables.h:1090 [inline] __nft_release_basechain+0x138/0x640 net/netfilter/nf_tables_api.c:9524 nft_netdev_event net/netfilter/nft_chain_filter.c:351 [inline] nf_tables_netdev_event+0x521/0x8a0 net/netfilter/nft_chain_filter.c:382 reproducer: unshare -n bash -c 'ip link add br0 type bridge; nft add table netdev t ; \ nft add chain netdev t ingress \{ type filter hook ingress device "br0" \ priority 0\; policy drop\; \}' Problem is that when netns device exit hooks create the UNREGISTER event, the .pre_exit hook for nf_tables core has already removed the base hook. Notifier attempts to do this again. The need to do base hook unregister unconditionally was needed in the past, because notifier was last stage where reg->dev dereference was safe. Now that nf_tables does the hook removal in .pre_exit, this isn't needed anymore. Reported-and-tested-by: syzbot+154bd5be532a63aa778b@syzkaller.appspotmail.com Fixes: 767d1216bff825 ("netfilter: nftables: fix possible UAF over chains from packet path in netns") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-05-29netfilter: nf_tables: remove unused arg in nft_set_pktinfo_unspec()Florian Westphal1-13/+13
The functions pass extra skb arg, but either its not used or the helpers can already access it via pkt->skb. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26netfilter: nftables: add nft_pernet() helper functionPablo Neira Ayuso1-4/+1
Consolidate call to net_generic(net, nf_tables_net_id) in this wrapper function. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-06netfilter: nf_tables: use net_generic infra for transaction dataFlorian Westphal1-3/+8
This moves all nf_tables pernet data from struct net to a net_generic extension, with the exception of the gencursor. The latter is used in the data path and also outside of the nf_tables core. All others are only used from the configuration plane. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-10-12netfilter: nf_tables: add inet ingress supportPablo Neira Ayuso1-1/+34
This patch adds a new ingress hook for the inet family. The inet ingress hook emulates the IP receive path code, therefore, unclean packets are drop before walking over the ruleset in this basechain. This patch also introduces the nft_base_chain_netdev() helper function to check if this hook is bound to one or more devices (through the hook list infrastructure). This check allows to perform the same handling for the inet ingress as it would be a netdev ingress chain from the control plane. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-10-23netfilter: nf_tables: support for multiple devices per netdev hookPablo Neira Ayuso1-19/+26
This patch allows you to register one netdev basechain to multiple devices. This adds a new NFTA_HOOK_DEVS netlink attribute to specify the list of netdevices. Basechains store a list of hooks. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-07-19netfilter: bridge: make NF_TABLES_BRIDGE tristateArnd Bergmann1-1/+1
The new nft_meta_bridge code fails to link as built-in when NF_TABLES is a loadable module. net/bridge/netfilter/nft_meta_bridge.o: In function `nft_meta_bridge_get_eval': nft_meta_bridge.c:(.text+0x1e8): undefined reference to `nft_meta_get_eval' net/bridge/netfilter/nft_meta_bridge.o: In function `nft_meta_bridge_get_init': nft_meta_bridge.c:(.text+0x468): undefined reference to `nft_meta_get_init' nft_meta_bridge.c:(.text+0x49c): undefined reference to `nft_parse_register' nft_meta_bridge.c:(.text+0x4cc): undefined reference to `nft_validate_register_store' net/bridge/netfilter/nft_meta_bridge.o: In function `nft_meta_bridge_module_exit': nft_meta_bridge.c:(.exit.text+0x14): undefined reference to `nft_unregister_expr' net/bridge/netfilter/nft_meta_bridge.o: In function `nft_meta_bridge_module_init': nft_meta_bridge.c:(.init.text+0x14): undefined reference to `nft_register_expr' net/bridge/netfilter/nft_meta_bridge.o:(.rodata+0x60): undefined reference to `nft_meta_get_dump' net/bridge/netfilter/nft_meta_bridge.o:(.rodata+0x88): undefined reference to `nft_meta_set_eval' This can happen because the NF_TABLES_BRIDGE dependency itself is just a 'bool'. Make the symbol a 'tristate' instead so Kconfig can propagate the dependencies correctly. Fixes: 30e103fe24de ("netfilter: nft_meta: move bridge meta keys into nft_meta_bridge") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-08-16netfilter: nf_tables: don't prevent event handler from device cleanup on ↵Florian Westphal1-5/+7
netns exit When a netnsamespace exits, the nf_tables pernet_ops will remove all rules. However, there is one caveat: Base chains that register ingress hooks will cause use-after-free: device is already gone at that point. The device event handlers prevent this from happening: netns exit synthesizes unregister events for all devices. However, an improper fix for a race condition made the notifiers a no-op in case they get called from netns exit path, so revert that part. This is safe now as the previous patch fixed nf_tables pernet ops and device notifier initialisation ordering. Fixes: 0a2cf5ee432c2 ("netfilter: nf_tables: close race between netns exit and rmmod") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-08-16netfilter: nf_tables: fix register orderingFlorian Westphal1-1/+1
We must register nfnetlink ops last, as that exposes nf_tables to userspace. Without this, we could theoretically get nfnetlink request before net->nft state has been initialized. Fixes: 99633ab29b213 ("netfilter: nf_tables: complete net namespace support") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-07-18netfilter: nf_tables: use dedicated mutex to guard transactionsFlorian Westphal1-2/+2
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 <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-06-12netfilter: nf_tables: close race between netns exit and rmmodFlorian Westphal1-0/+5
If net namespace is exiting while nf_tables module is being removed we can oops: BUG: unable to handle kernel NULL pointer dereference at 0000000000000040 IP: nf_tables_flowtable_event+0x43/0xf0 [nf_tables] PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI Modules linked in: nf_tables(-) nfnetlink [..] unregister_netdevice_notifier+0xdd/0x130 nf_tables_module_exit+0x24/0x3a [nf_tables] SyS_delete_module+0x1c5/0x240 do_syscall_64+0x74/0x190 Avoid this by attempting to take reference on the net namespace from the notifiers. If it fails the namespace is exiting already, and nft core is taking care of cleanup work. We also need to make sure the netdev hook type gets removed before netns ops removal, else notifier might be invoked with device event for a netns where net->nft was never initialised (because pernet ops was removed beforehand). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-03-30netfilter: nf_tables: build-in filter chain typePablo Neira Ayuso1-0/+398
One module per supported filter chain family type takes too much memory for very little code - too much modularization - place all chain filter definitions in one single file. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>