linux/net/netfilter, branch v5.10

netfilter: nft_ct: Remove confirmation check for NFT_CT_ID

2020-12-09T09:31:58Z

Since commit 656c8e9cc1ba ("netfilter: conntrack: Use consistent ct id hash calculation") the ct id will not change from initialization to confirmation. Removing the confirmation check allows for things like adding an element to a 'typeof ct id' set in prerouting upon reception of the first packet of a new connection, and then being able to reference that set consistently both before and after the connection is confirmed. Fixes: 656c8e9cc1ba ("netfilter: conntrack: Use consistent ct id hash calculation") Signed-off-by: Brett Mastbergen Acked-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: nftables: comment indirect serialization of commit_mutex with rtnl_mutex

2020-12-08T20:53:48Z

Add an explicit comment in the code to describe the indirect serialization of the holders of the commit_mutex with the rtnl_mutex. Commit 90d2723c6d4c ("netfilter: nf_tables: do not hold reference on netdevice from preparation phase") already describes this, but a comment in this case is better for reference. Reported-by: Vladimir Oltean Reviewed-by: Vladimir Oltean Signed-off-by: Pablo Neira Ayuso

netfilter: nft_dynset: fix timeouts later than 23 days

2020-12-08T19:42:11Z

Use nf_msecs_to_jiffies64 and nf_jiffies64_to_msecs as provided by 8e1102d5a159 ("netfilter: nf_tables: support timeouts larger than 23 days"), otherwise ruleset listing breaks. Fixes: a8b1e36d0d1d ("netfilter: nft_dynset: fix element timeout for HZ != 1000") Signed-off-by: Pablo Neira Ayuso

netfilter: x_tables: Switch synchronization to RCU

2020-12-08T11:57:39Z

When running concurrent iptables rules replacement with data, the per CPU sequence count is checked after the assignment of the new information. The sequence count is used to synchronize with the packet path without the use of any explicit locking. If there are any packets in the packet path using the table information, the sequence count is incremented to an odd value and is incremented to an even after the packet process completion. The new table value assignment is followed by a write memory barrier so every CPU should see the latest value. If the packet path has started with the old table information, the sequence counter will be odd and the iptables replacement will wait till the sequence count is even prior to freeing the old table info. However, this assumes that the new table information assignment and the memory barrier is actually executed prior to the counter check in the replacement thread. If CPU decides to execute the assignment later as there is no user of the table information prior to the sequence check, the packet path in another CPU may use the old table information. The replacement thread would then free the table information under it leading to a use after free in the packet processing context- Unable to handle kernel NULL pointer dereference at virtual address 000000000000008e pc : ip6t_do_table+0x5d0/0x89c lr : ip6t_do_table+0x5b8/0x89c ip6t_do_table+0x5d0/0x89c ip6table_filter_hook+0x24/0x30 nf_hook_slow+0x84/0x120 ip6_input+0x74/0xe0 ip6_rcv_finish+0x7c/0x128 ipv6_rcv+0xac/0xe4 __netif_receive_skb+0x84/0x17c process_backlog+0x15c/0x1b8 napi_poll+0x88/0x284 net_rx_action+0xbc/0x23c __do_softirq+0x20c/0x48c This could be fixed by forcing instruction order after the new table information assignment or by switching to RCU for the synchronization. Fixes: 80055dab5de0 ("netfilter: x_tables: make xt_replace_table wait until old rules are not used anymore") Reported-by: Sean Tranchetti Reported-by: kernel test robot Suggested-by: Florian Westphal Signed-off-by: Subash Abhinov Kasiviswanathan Signed-off-by: Pablo Neira Ayuso

netfilter: nftables_offload: build mask based from the matching bytes

2020-11-27T11:10:47Z

Userspace might match on prefix bytes of header fields if they are on the byte boundary, this requires that the mask is adjusted accordingly. Use NFT_OFFLOAD_MATCH_EXACT() for meta since prefix byte matching is not allowed for this type of selector. The bitwise expression might be optimized out by userspace, hence the kernel needs to infer the prefix from the number of payload bytes to match on. This patch adds nft_payload_offload_mask() to calculate the bitmask to match on the prefix. Fixes: c9626a2cbdb2 ("netfilter: nf_tables: add hardware offload support") Signed-off-by: Pablo Neira Ayuso

netfilter: nftables_offload: set address type in control dissector

2020-11-27T11:10:46Z

This patch adds nft_flow_rule_set_addr_type() to set the address type from the nft_payload expression accordingly. If the address type is not set in the control dissector then a rule that matches either on source or destination IP address does not work. After this patch, nft hardware offload generates the flow dissector configuration as tc-flower does to match on an IP address. This patch has been also tested functionally to make sure packets are filtered out by the NIC. This is also getting the code aligned with the existing netfilter flow offload infrastructure which is also setting the control dissector. Fixes: c9626a2cbdb2 ("netfilter: nf_tables: add hardware offload support") Signed-off-by: Pablo Neira Ayuso

ipvs: fix possible memory leak in ip_vs_control_net_init

2020-11-27T11:10:46Z

kmemleak report a memory leak as follows: BUG: memory leak unreferenced object 0xffff8880759ea000 (size 256): backtrace: [<00000000c0bf2deb>] kmem_cache_zalloc include/linux/slab.h:656 [inline] [<00000000c0bf2deb>] __proc_create+0x23d/0x7d0 fs/proc/generic.c:421 [<000000009d718d02>] proc_create_reg+0x8e/0x140 fs/proc/generic.c:535 [<0000000097bbfc4f>] proc_create_net_data+0x8c/0x1b0 fs/proc/proc_net.c:126 [<00000000652480fc>] ip_vs_control_net_init+0x308/0x13a0 net/netfilter/ipvs/ip_vs_ctl.c:4169 [<000000004c927ebe>] __ip_vs_init+0x211/0x400 net/netfilter/ipvs/ip_vs_core.c:2429 [<00000000aa6b72d9>] ops_init+0xa8/0x3c0 net/core/net_namespace.c:151 [<00000000153fd114>] setup_net+0x2de/0x7e0 net/core/net_namespace.c:341 [<00000000be4e4f07>] copy_net_ns+0x27d/0x530 net/core/net_namespace.c:482 [<00000000f1c23ec9>] create_new_namespaces+0x382/0xa30 kernel/nsproxy.c:110 [<00000000098a5757>] copy_namespaces+0x2e6/0x3b0 kernel/nsproxy.c:179 [<0000000026ce39e9>] copy_process+0x220a/0x5f00 kernel/fork.c:2072 [<00000000b71f4efe>] _do_fork+0xc7/0xda0 kernel/fork.c:2428 [<000000002974ee96>] __do_sys_clone3+0x18a/0x280 kernel/fork.c:2703 [<0000000062ac0a4d>] do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 [<0000000093f1ce2c>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 In the error path of ip_vs_control_net_init(), remove_proc_entry() needs to be called to remove the added proc entry, otherwise a memory leak will occur. Also, add some '#ifdef CONFIG_PROC_FS' because proc_create_net* return NULL when PROC is not used. Fixes: b17fc9963f83 ("IPVS: netns, ip_vs_stats and its procfs") Fixes: 61b1ab4583e2 ("IPVS: netns, add basic init per netns.") Reported-by: Hulk Robot Signed-off-by: Wang Hai Acked-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: avoid false-postive lockdep splat

2020-11-25T23:09:42Z

There are reports wrt lockdep splat in nftables, e.g.: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 31416 at net/netfilter/nf_tables_api.c:622 lockdep_nfnl_nft_mutex_not_held+0x28/0x38 [nf_tables] ... These are caused by an earlier, unrelated bug such as a n ABBA deadlock in a different subsystem. In such an event, lockdep is disabled and lockdep_is_held returns true unconditionally. This then causes the WARN() in nf_tables. Make the WARN conditional on lockdep still active to avoid this. Fixes: f102d66b335a417 ("netfilter: nf_tables: use dedicated mutex to guard transactions") Reported-by: Naresh Kamboju Link: https://lore.kernel.org/linux-kselftest/CA+G9fYvFUpODs+NkSYcnwKnXm62tmP=ksLeBPmB+KFrB2rvCtQ@mail.gmail.com/ Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: ipset: prevent uninit-value in hash_ip6_add

2020-11-25T23:09:42Z

syzbot found that we are not validating user input properly before copying 16 bytes [1]. Using NLA_BINARY in ipaddr_policy[] for IPv6 address is not correct, since it ensures at most 16 bytes were provided. We should instead make sure user provided exactly 16 bytes. In old kernels (before v4.20), fix would be to remove the NLA_BINARY, since NLA_POLICY_EXACT_LEN() was not yet available. [1] BUG: KMSAN: uninit-value in hash_ip6_add+0x1cba/0x3a50 net/netfilter/ipset/ip_set_hash_gen.h:892 CPU: 1 PID: 11611 Comm: syz-executor.0 Not tainted 5.10.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x21c/0x280 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197 hash_ip6_add+0x1cba/0x3a50 net/netfilter/ipset/ip_set_hash_gen.h:892 hash_ip6_uadt+0x976/0xbd0 net/netfilter/ipset/ip_set_hash_ip.c:267 call_ad+0x329/0xd00 net/netfilter/ipset/ip_set_core.c:1720 ip_set_ad+0x111f/0x1440 net/netfilter/ipset/ip_set_core.c:1808 ip_set_uadd+0xf6/0x110 net/netfilter/ipset/ip_set_core.c:1833 nfnetlink_rcv_msg+0xc7d/0xdf0 net/netfilter/nfnetlink.c:252 netlink_rcv_skb+0x70a/0x820 net/netlink/af_netlink.c:2494 nfnetlink_rcv+0x4f0/0x4380 net/netfilter/nfnetlink.c:600 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x11da/0x14b0 net/netlink/af_netlink.c:1330 netlink_sendmsg+0x173c/0x1840 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg net/socket.c:671 [inline] ____sys_sendmsg+0xc7a/0x1240 net/socket.c:2353 ___sys_sendmsg net/socket.c:2407 [inline] __sys_sendmsg+0x6d5/0x830 net/socket.c:2440 __do_sys_sendmsg net/socket.c:2449 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45deb9 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe2e503fc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000029ec0 RCX: 000000000045deb9 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000003 RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 000000000169fb7f R14: 00007fe2e50409c0 R15: 000000000118bf2c Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline] kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:289 __msan_chain_origin+0x57/0xa0 mm/kmsan/kmsan_instr.c:147 ip6_netmask include/linux/netfilter/ipset/pfxlen.h:49 [inline] hash_ip6_netmask net/netfilter/ipset/ip_set_hash_ip.c:185 [inline] hash_ip6_uadt+0xb1c/0xbd0 net/netfilter/ipset/ip_set_hash_ip.c:263 call_ad+0x329/0xd00 net/netfilter/ipset/ip_set_core.c:1720 ip_set_ad+0x111f/0x1440 net/netfilter/ipset/ip_set_core.c:1808 ip_set_uadd+0xf6/0x110 net/netfilter/ipset/ip_set_core.c:1833 nfnetlink_rcv_msg+0xc7d/0xdf0 net/netfilter/nfnetlink.c:252 netlink_rcv_skb+0x70a/0x820 net/netlink/af_netlink.c:2494 nfnetlink_rcv+0x4f0/0x4380 net/netfilter/nfnetlink.c:600 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x11da/0x14b0 net/netlink/af_netlink.c:1330 netlink_sendmsg+0x173c/0x1840 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg net/socket.c:671 [inline] ____sys_sendmsg+0xc7a/0x1240 net/socket.c:2353 ___sys_sendmsg net/socket.c:2407 [inline] __sys_sendmsg+0x6d5/0x830 net/socket.c:2440 __do_sys_sendmsg net/socket.c:2449 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline] kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:289 kmsan_memcpy_memmove_metadata+0x25e/0x2d0 mm/kmsan/kmsan.c:226 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:246 __msan_memcpy+0x46/0x60 mm/kmsan/kmsan_instr.c:110 ip_set_get_ipaddr6+0x2cb/0x370 net/netfilter/ipset/ip_set_core.c:310 hash_ip6_uadt+0x439/0xbd0 net/netfilter/ipset/ip_set_hash_ip.c:255 call_ad+0x329/0xd00 net/netfilter/ipset/ip_set_core.c:1720 ip_set_ad+0x111f/0x1440 net/netfilter/ipset/ip_set_core.c:1808 ip_set_uadd+0xf6/0x110 net/netfilter/ipset/ip_set_core.c:1833 nfnetlink_rcv_msg+0xc7d/0xdf0 net/netfilter/nfnetlink.c:252 netlink_rcv_skb+0x70a/0x820 net/netlink/af_netlink.c:2494 nfnetlink_rcv+0x4f0/0x4380 net/netfilter/nfnetlink.c:600 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x11da/0x14b0 net/netlink/af_netlink.c:1330 netlink_sendmsg+0x173c/0x1840 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg net/socket.c:671 [inline] ____sys_sendmsg+0xc7a/0x1240 net/socket.c:2353 ___sys_sendmsg net/socket.c:2407 [inline] __sys_sendmsg+0x6d5/0x830 net/socket.c:2440 __do_sys_sendmsg net/socket.c:2449 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline] kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:104 kmsan_slab_alloc+0x8d/0xe0 mm/kmsan/kmsan_hooks.c:76 slab_alloc_node mm/slub.c:2906 [inline] __kmalloc_node_track_caller+0xc61/0x15f0 mm/slub.c:4512 __kmalloc_reserve net/core/skbuff.c:142 [inline] __alloc_skb+0x309/0xae0 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1094 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1176 [inline] netlink_sendmsg+0xdb8/0x1840 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg net/socket.c:671 [inline] ____sys_sendmsg+0xc7a/0x1240 net/socket.c:2353 ___sys_sendmsg net/socket.c:2407 [inline] __sys_sendmsg+0x6d5/0x830 net/socket.c:2440 __do_sys_sendmsg net/socket.c:2449 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: a7b4f989a629 ("netfilter: ipset: IP set core support") Signed-off-by: Eric Dumazet Reported-by: syzbot Acked-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso

netfilter: ipset: Update byte and packet counters regardless of whether they match

2020-10-31T10:11:11Z

In ip_set_match_extensions(), for sets with counters, we take care of updating counters themselves by calling ip_set_update_counter(), and of checking if the given comparison and values match, by calling ip_set_match_counter() if needed. However, if a given comparison on counters doesn't match the configured values, that doesn't mean the set entry itself isn't matching. This fix restores the behaviour we had before commit 4750005a85f7 ("netfilter: ipset: Fix "don't update counters" mode when counters used at the matching"), without reintroducing the issue fixed there: back then, mtype_data_match() first updated counters in any case, and then took care of matching on counters. Now, if the IPSET_FLAG_SKIP_COUNTER_UPDATE flag is set, ip_set_update_counter() will anyway skip counter updates if desired. The issue observed is illustrated by this reproducer: ipset create c hash:ip counters ipset add c 192.0.2.1 iptables -I INPUT -m set --match-set c src --bytes-gt 800 -j DROP if we now send packets from 192.0.2.1, bytes and packets counters for the entry as shown by 'ipset list' are always zero, and, no matter how many bytes we send, the rule will never match, because counters themselves are not updated. Reported-by: Mithil Mhatre Fixes: 4750005a85f7 ("netfilter: ipset: Fix "don't update counters" mode when counters used at the matching") Signed-off-by: Stefano Brivio Signed-off-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso