kernel/linux.git/include/net/netfilter, branch v4.4.270

netfilter: nf_tables: fix destination register zeroing

2020-09-12T09:45:27+00:00

[ Upstream commit 1e105e6afa6c3d32bfb52c00ffa393894a525c27 ] Following bug was reported via irc: nft list ruleset set knock_candidates_ipv4 { type ipv4_addr . inet_service size 65535 elements = { 127.0.0.1 . 123, 127.0.0.1 . 123 } } .. udp dport 123 add @knock_candidates_ipv4 { ip saddr . 123 } udp dport 123 add @knock_candidates_ipv4 { ip saddr . udp dport } It should not have been possible to add a duplicate set entry. After some debugging it turned out that the problem is the immediate value (123) in the second-to-last rule. Concatenations use 32bit registers, i.e. the elements are 8 bytes each, not 6 and it turns out the kernel inserted inet firewall @knock_candidates_ipv4 element 0100007f ffff7b00 : 0 [end] element 0100007f 00007b00 : 0 [end] Note the non-zero upper bits of the first element. It turns out that nft_immediate doesn't zero the destination register, but this is needed when the length isn't a multiple of 4. Furthermore, the zeroing in nft_payload is broken. We can't use [len / 4] = 0 -- if len is a multiple of 4, index is off by one. Skip zeroing in this case and use a conditional instead of (len -1) / 4. Fixes: 49499c3e6e18 ("netfilter: nf_tables: switch registers to 32 bit addressing") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: conntrack: avoid gcc-10 zero-length-bounds warning

2020-05-20T06:11:47+00:00

[ Upstream commit 2c407aca64977ede9b9f35158e919773cae2082f ] gcc-10 warns around a suspicious access to an empty struct member: net/netfilter/nf_conntrack_core.c: In function '__nf_conntrack_alloc': net/netfilter/nf_conntrack_core.c:1522:9: warning: array subscript 0 is outside the bounds of an interior zero-length array 'u8[0]' {aka 'unsigned char[0]'} [-Wzero-length-bounds] 1522 | memset(&ct->__nfct_init_offset[0], 0, | ^~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from net/netfilter/nf_conntrack_core.c:37: include/net/netfilter/nf_conntrack.h:90:5: note: while referencing '__nfct_init_offset' 90 | u8 __nfct_init_offset[0]; | ^~~~~~~~~~~~~~~~~~ The code is correct but a bit unusual. Rework it slightly in a way that does not trigger the warning, using an empty struct instead of an empty array. There are probably more elegant ways to do this, but this is the smallest change. Fixes: c41884ce0562 ("netfilter: conntrack: avoid zeroing timer") Signed-off-by: Arnd Bergmann Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: nf_tables: Align nft_expr private data to 64-bit

2019-11-12T18:13:21+00:00

commit 250367c59e6ba0d79d702a059712d66edacd4a1a upstream. Invoking the following commands on a 32-bit architecture with strict alignment requirements (such as an ARMv7-based Raspberry Pi) results in an alignment exception: # nft add table ip test-ip4 # nft add chain ip test-ip4 output { type filter hook output priority 0; } # nft add rule ip test-ip4 output quota 1025 bytes Alignment trap: not handling instruction e1b26f9f at [<7f4473f8>] Unhandled fault: alignment exception (0x001) at 0xb832e824 Internal error: : 1 [#1] PREEMPT SMP ARM Hardware name: BCM2835 [<7f4473fc>] (nft_quota_do_init [nft_quota]) [<7f447448>] (nft_quota_init [nft_quota]) [<7f4260d0>] (nf_tables_newrule [nf_tables]) [<7f4168dc>] (nfnetlink_rcv_batch [nfnetlink]) [<7f416bd0>] (nfnetlink_rcv [nfnetlink]) [<8078b334>] (netlink_unicast) [<8078b664>] (netlink_sendmsg) [<8071b47c>] (sock_sendmsg) [<8071bd18>] (___sys_sendmsg) [<8071ce3c>] (__sys_sendmsg) [<8071ce94>] (sys_sendmsg) The reason is that nft_quota_do_init() calls atomic64_set() on an atomic64_t which is only aligned to 32-bit, not 64-bit, because it succeeds struct nft_expr in memory which only contains a 32-bit pointer. Fix by aligning the nft_expr private data to 64-bit. Fixes: 96518518cc41 ("netfilter: add nftables") Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v3.13+ Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: ctnetlink: don't use conntrack/expect object addresses as id

2019-09-06T08:18:13+00:00

commit 3c79107631db1f7fd32cf3f7368e4672004a3010 upstream. else, we leak the addresses to userspace via ctnetlink events and dumps. Compute an ID on demand based on the immutable parts of nf_conn struct. Another advantage compared to using an address is that there is no immediate re-use of the same ID in case the conntrack entry is freed and reallocated again immediately. Fixes: 3583240249ef ("[NETFILTER]: nf_conntrack_expect: kill unique ID") Fixes: 7f85f914721f ("[NETFILTER]: nf_conntrack: kill unique ID") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso [bwh: Backported to 4.4: adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Sasha Levin

netfilter: physdev: relax br_netfilter dependency

2019-04-27T07:33:53+00:00

[ Upstream commit 8e2f311a68494a6677c1724bdcb10bada21af37c ] Following command: iptables -D FORWARD -m physdev ... causes connectivity loss in some setups. Reason is that iptables userspace will probe kernel for the module revision of the physdev patch, and physdev has an artificial dependency on br_netfilter (xt_physdev use makes no sense unless a br_netfilter module is loaded). This causes the "phydev" module to be loaded, which in turn enables the "call-iptables" infrastructure. bridged packets might then get dropped by the iptables ruleset. The better fix would be to change the "call-iptables" defaults to 0 and enforce explicit setting to 1, but that breaks backwards compatibility. This does the next best thing: add a request_module call to checkentry. This was a stray '-D ... -m physdev' won't activate br_netfilter anymore. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: nf_queue: Make the queue_handler pernet

2018-02-16T19:09:40+00:00

commit dc3ee32e96d74dd6c80eed63af5065cb75899299 upstream. Florian Weber reported: > Under full load (unshare() in loop -> OOM conditions) we can > get kernel panic: > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 > IP: [] nfqnl_nf_hook_drop+0x35/0x70 > [..] > task: ffff88012dfa3840 ti: ffff88012dffc000 task.ti: ffff88012dffc000 > RIP: 0010:[] [] nfqnl_nf_hook_drop+0x35/0x70 > RSP: 0000:ffff88012dfffd80 EFLAGS: 00010206 > RAX: 0000000000000008 RBX: ffffffff81add0c0 RCX: ffff88013fd80000 > [..] > Call Trace: > [] nf_queue_nf_hook_drop+0x18/0x20 > [] nf_unregister_net_hook+0xdb/0x150 > [] netfilter_net_exit+0x2f/0x60 > [] ops_exit_list.isra.4+0x38/0x60 > [] setup_net+0xc2/0x120 > [] copy_net_ns+0x79/0x120 > [] create_new_namespaces+0x11b/0x1e0 > [] unshare_nsproxy_namespaces+0x57/0xa0 > [] SyS_unshare+0x1b2/0x340 > [] entry_SYSCALL_64_fastpath+0x1e/0xa8 > Code: 65 00 48 89 e5 41 56 41 55 41 54 53 83 e8 01 48 8b 97 70 12 00 00 48 98 49 89 f4 4c 8b 74 c2 18 4d 8d 6e 08 49 81 c6 88 00 00 00 <49> 8b 5d 00 48 85 db 74 1a 48 89 df 4c 89 e2 48 c7 c6 90 68 47 > The simple fix for this requires a new pernet variable for struct nf_queue that indicates when it is safe to use the dynamically allocated nf_queue state. As we need a variable anyway make nf_register_queue_handler and nf_unregister_queue_handler pernet. This allows the existing logic of when it is safe to use the state from the nfnetlink_queue module to be reused with no changes except for making it per net. The syncrhonize_rcu from nf_unregister_queue_handler is moved to a new function nfnl_queue_net_exit_batch so that the worst case of having a syncrhonize_rcu in the pernet exit path is not experienced in batch mode. Reported-by: Florian Westphal Signed-off-by: "Eric W. Biederman" Acked-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Cc: Eric Biggers Signed-off-by: Greg Kroah-Hartman

netfilter: nf_tables: add clone interface to expression operations

2015-11-10T22:47:32+00:00

With the conversion of the counter expressions to make it percpu, we need to clone the percpu memory area, otherwise we crash when using counters from flow tables. Signed-off-by: Pablo Neira Ayuso

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

2015-10-17T12:28:03+00:00

This merge resolves conflicts with 75aec9df3a78 ("bridge: Remove br_nf_push_frag_xmit_sk") as part of Eric Biederman's effort to improve netns support in the network stack that reached upstream via David's net-next tree. Signed-off-by: Pablo Neira Ayuso Conflicts: net/bridge/br_netfilter_hooks.c

netfilter: make nf_queue_entry_get_refs return void

2015-10-16T16:22:23+00:00

We don't care if module is being unloaded anymore since hook unregister handling will destroy queue entries using that hook. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

ipv6: Pass struct net into nf_ct_frag6_gather

2015-10-13T02:44:17+00:00

The function nf_ct_frag6_gather is called on both the input and the output paths of the networking stack. In particular ipv6_defrag which calls nf_ct_frag6_gather is called from both the the PRE_ROUTING chain on input and the LOCAL_OUT chain on output. The addition of a net parameter makes it explicit which network namespace the packets are being reassembled in, and removes the need for nf_ct_frag6_gather to guess. Signed-off-by: "Eric W. Biederman" Acked-by: Pablo Neira Ayuso Signed-off-by: David S. Miller