linux/net/ipv4
Kuniyuki Iwashima 5830aa8639 netfilter: iptables: Fix null-ptr-deref in iptable_nat_table_init().
We had a report that iptables-restore sometimes triggered null-ptr-deref
at boot time. [0]

The problem is that iptable_nat_table_init() is exposed to user space
before the kernel fully initialises netns.

In the small race window, a user could call iptable_nat_table_init()
that accesses net_generic(net, iptable_nat_net_id), which is available
only after registering iptable_nat_net_ops.

Let's call register_pernet_subsys() before xt_register_template().

[0]:
bpfilter: Loaded bpfilter_umh pid 11702
Started bpfilter
BUG: kernel NULL pointer dereference, address: 0000000000000013
 PF: supervisor write access in kernel mode
 PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
PREEMPT SMP NOPTI
CPU: 2 PID: 11879 Comm: iptables-restor Not tainted 6.1.92-99.174.amzn2023.x86_64 #1
Hardware name: Amazon EC2 c6i.4xlarge/, BIOS 1.0 10/16/2017
RIP: 0010:iptable_nat_table_init (net/ipv4/netfilter/iptable_nat.c:87 net/ipv4/netfilter/iptable_nat.c:121) iptable_nat
Code: 10 4c 89 f6 48 89 ef e8 0b 19 bb ff 41 89 c4 85 c0 75 38 41 83 c7 01 49 83 c6 28 41 83 ff 04 75 dc 48 8b 44 24 08 48 8b 0c 24 <48> 89 08 4c 89 ef e8 a2 3b a2 cf 48 83 c4 10 44 89 e0 5b 5d 41 5c
RSP: 0018:ffffbef902843cd0 EFLAGS: 00010246
RAX: 0000000000000013 RBX: ffff9f4b052caa20 RCX: ffff9f4b20988d80
RDX: 0000000000000000 RSI: 0000000000000064 RDI: ffffffffc04201c0
RBP: ffff9f4b29394000 R08: ffff9f4b07f77258 R09: ffff9f4b07f77240
R10: 0000000000000000 R11: ffff9f4b09635388 R12: 0000000000000000
R13: ffff9f4b1a3c6c00 R14: ffff9f4b20988e20 R15: 0000000000000004
FS:  00007f6284340000(0000) GS:ffff9f51fe280000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000013 CR3: 00000001d10a6005 CR4: 00000000007706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <TASK>
 ? show_trace_log_lvl (arch/x86/kernel/dumpstack.c:259)
 ? show_trace_log_lvl (arch/x86/kernel/dumpstack.c:259)
 ? xt_find_table_lock (net/netfilter/x_tables.c:1259)
 ? __die_body.cold (arch/x86/kernel/dumpstack.c:478 arch/x86/kernel/dumpstack.c:420)
 ? page_fault_oops (arch/x86/mm/fault.c:727)
 ? exc_page_fault (./arch/x86/include/asm/irqflags.h:40 ./arch/x86/include/asm/irqflags.h:75 arch/x86/mm/fault.c:1470 arch/x86/mm/fault.c:1518)
 ? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:570)
 ? iptable_nat_table_init (net/ipv4/netfilter/iptable_nat.c:87 net/ipv4/netfilter/iptable_nat.c:121) iptable_nat
 xt_find_table_lock (net/netfilter/x_tables.c:1259)
 xt_request_find_table_lock (net/netfilter/x_tables.c:1287)
 get_info (net/ipv4/netfilter/ip_tables.c:965)
 ? security_capable (security/security.c:809 (discriminator 13))
 ? ns_capable (kernel/capability.c:376 kernel/capability.c:397)
 ? do_ipt_get_ctl (net/ipv4/netfilter/ip_tables.c:1656)
 ? bpfilter_send_req (net/bpfilter/bpfilter_kern.c:52) bpfilter
 nf_getsockopt (net/netfilter/nf_sockopt.c:116)
 ip_getsockopt (net/ipv4/ip_sockglue.c:1827)
 __sys_getsockopt (net/socket.c:2327)
 __x64_sys_getsockopt (net/socket.c:2342 net/socket.c:2339 net/socket.c:2339)
 do_syscall_64 (arch/x86/entry/common.c:51 arch/x86/entry/common.c:81)
 entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
RIP: 0033:0x7f62844685ee
Code: 48 8b 0d 45 28 0f 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 0a c3 66 0f 1f 84 00 00 00 00 00 48 8b 15 09
RSP: 002b:00007ffd1f83d638 EFLAGS: 00000246 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 00007ffd1f83d680 RCX: 00007f62844685ee
RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 0000000000000004 R08: 00007ffd1f83d670 R09: 0000558798ffa2a0
R10: 00007ffd1f83d680 R11: 0000000000000246 R12: 00007ffd1f83e3b2
R13: 00007f628455baa0 R14: 00007ffd1f83d7b0 R15: 00007f628457a008
 </TASK>
Modules linked in: iptable_nat(+) bpfilter rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache veth xt_state xt_connmark xt_nat xt_statistic xt_MASQUERADE xt_mark xt_addrtype ipt_REJECT nf_reject_ipv4 nft_chain_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 xt_comment nft_compat nf_tables nfnetlink overlay nls_ascii nls_cp437 vfat fat ghash_clmulni_intel aesni_intel ena crypto_simd ptp cryptd i8042 pps_core serio button sunrpc sch_fq_codel configfs loop dm_mod fuse dax dmi_sysfs crc32_pclmul crc32c_intel efivarfs
CR2: 0000000000000013

Fixes: fdacd57c79 ("netfilter: x_tables: never register tables by default")
Reported-by: Takahiro Kawahara <takawaha@amazon.co.jp>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-07-31 23:20:50 +02:00
..
netfilter netfilter: iptables: Fix null-ptr-deref in iptable_nat_table_init(). 2024-07-31 23:20:50 +02:00
af_inet.c net: gro: initialize network_offset in network layer 2024-05-27 16:46:59 -07:00
ah4.c net: fill in MODULE_DESCRIPTION()s for ipv4 modules 2024-02-09 14:12:02 -08:00
arp.c arp: Convert ioctl(SIOCGARP) to RCU. 2024-05-01 18:37:07 -07:00
bpf_tcp_ca.c bpf: pass bpf_struct_ops_link to callbacks in bpf_struct_ops. 2024-05-30 15:34:13 -07:00
cipso_ipv4.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-06-20 13:49:59 -07:00
datagram.c ipv4: Set the routing scope properly in ip_route_output_ports(). 2024-02-12 17:33:05 -08:00
devinet.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
esp4_offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-07-15 13:19:17 -07:00
esp4.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-07-15 13:19:17 -07:00
fib_frontend.c rtnetlink: make the "split" NLM_DONE handling generic 2024-06-05 12:34:54 +01:00
fib_lookup.h
fib_notifier.c
fib_rules.c fib: remove unnecessary input parameters in fib_default_rule_add 2024-01-03 16:42:48 -08:00
fib_semantics.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-07-15 13:19:17 -07:00
fib_trie.c ipv4: Fix incorrect TOS in route get reply 2024-07-18 11:11:02 +02:00
fou_bpf.c ip_tunnel: convert __be16 tunnel flags to bitmaps 2024-04-01 10:49:28 +01:00
fou_core.c fou: remove warn in gue_gro_receive on unsupported protocol 2024-06-17 17:49:50 -07:00
fou_nl.c net: ynl: prefix uAPI header include with uapi/ 2023-05-26 10:30:14 +01:00
fou_nl.h net: ynl: prefix uAPI header include with uapi/ 2023-05-26 10:30:14 +01:00
gre_demux.c ip_tunnel: convert __be16 tunnel flags to bitmaps 2024-04-01 10:49:28 +01:00
gre_offload.c net: gro: rename skb_gro_header_hard() 2024-03-05 13:30:11 +01:00
icmp.c net/ipv4: add tracepoint for icmp_send 2024-05-08 10:39:26 +01:00
igmp.c ipv4: Set scope explicitly in ip_route_output(). 2024-04-08 13:20:51 +01:00
inet_connection_sock.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-06-27 12:14:11 -07:00
inet_diag.c inet_diag: Initialize pad field in struct inet_diag_req_v2 2024-07-04 15:25:09 +02:00
inet_fragment.c net: Rename mono_delivery_time to tstamp_type for scalabilty 2024-05-23 14:14:23 -07:00
inet_hashtables.c tcp: get rid of twsk_unique() 2024-05-09 20:25:55 -07:00
inet_timewait_sock.c tcp: move inet_twsk_schedule helper out of header 2024-06-10 11:54:18 +01:00
inetpeer.c net: ipv4: Simplify the allocation of slab caches in inet_initpeers 2024-01-31 16:39:42 -08:00
ip_forward.c net: fix IPSTATS_MIB_OUTFORWDATAGRAMS increment after fragment check 2023-10-13 09:58:45 -07:00
ip_fragment.c net: Rename mono_delivery_time to tstamp_type for scalabilty 2024-05-23 14:14:23 -07:00
ip_gre.c net: annotate writes on dev->mtu from ndo_change_mtu() 2024-05-07 16:19:14 -07:00
ip_input.c inet: introduce dst_rtable() helper 2024-04-30 18:32:38 -07:00
ip_options.c
ip_output.c net: Add additional bit to support clockid_t timestamp type 2024-05-23 14:14:36 -07:00
ip_sockglue.c inet: Add getsockopt support for IP_ROUTER_ALERT and IPV6_ROUTER_ALERT 2024-03-06 12:37:06 +00:00
ip_tunnel_core.c ip_tunnel: convert __be16 tunnel flags to bitmaps 2024-04-01 10:49:28 +01:00
ip_tunnel.c ip_tunnel: Move stats allocation to core 2024-06-11 19:24:37 -07:00
ip_vti.c ip_tunnel: convert __be16 tunnel flags to bitmaps 2024-04-01 10:49:28 +01:00
ipcomp.c
ipconfig.c net: ipconfig: move ic_nameservers_fallback into #ifdef block 2023-05-22 11:17:55 +01:00
ipip.c ip_tunnel: convert __be16 tunnel flags to bitmaps 2024-04-01 10:49:28 +01:00
ipmr_base.c
ipmr.c ip_tunnel: use a separate struct to store tunnel params in the kernel 2024-04-01 10:49:28 +01:00
Kconfig net/tcp: Add TCP-AO config and structures 2023-10-27 10:35:44 +01:00
Makefile bpfilter: remove bpfilter 2024-01-04 10:23:10 -08:00
metrics.c net: remove NULL-pointer net parameter in ip_metrics_convert 2024-06-05 10:06:00 +01:00
netfilter.c xfrm: pass struct net to xfrm_decode_session wrappers 2023-10-06 08:31:53 +02:00
netlink.c
nexthop.c net: nexthop: Initialize all fields in dumped nexthops 2024-07-24 15:13:43 +01:00
ping.c ping: use sk_skb_reason_drop to free rx packets 2024-06-19 12:44:22 +01:00
proc.c net: add <net/proto_memory.h> 2024-04-30 18:46:52 -07:00
protocol.c
raw_diag.c inet_diag: add module pointer to "struct inet_diag_handler" 2024-01-23 15:13:54 +01:00
raw.c net: raw: use sk_skb_reason_drop to free rx packets 2024-06-19 12:44:22 +01:00
route.c A lot of networking people were at a conference last week, busy 2024-07-25 13:32:25 -07:00
syncookies.c tcp: use sk_skb_reason_drop to free rx packets 2024-06-19 12:44:22 +01:00
sysctl_net_ipv4.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
tcp_ao.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-06-20 13:49:59 -07:00
tcp_bbr.c tcp: Add new args for cong_control in tcp_congestion_ops 2024-05-02 16:26:56 -07:00
tcp_bic.c
tcp_bpf.c tcp_bpf: properly release resources on error paths 2023-10-18 18:09:31 -07:00
tcp_cdg.c
tcp_cong.c tcp: Replace strncpy() with strscpy() 2024-07-16 07:52:15 -07:00
tcp_cubic.c bpf: Remove CONFIG_X86 and CONFIG_DYNAMIC_FTRACE guard from the tcp-cc kfuncs 2024-03-28 18:31:40 -07:00
tcp_dctcp.c tcp: Fix shift-out-of-bounds in dctcp_update_alpha(). 2024-05-21 13:34:50 +02:00
tcp_dctcp.h
tcp_diag.c inet_diag: add module pointer to "struct inet_diag_handler" 2024-01-23 15:13:54 +01:00
tcp_fastopen.c net: use unrcu_pointer() helper 2024-06-06 11:52:52 +02:00
tcp_highspeed.c
tcp_htcp.c
tcp_hybla.c
tcp_illinois.c
tcp_input.c tcp: Adjust clamping window for applications specifying SO_RCVBUF 2024-07-29 11:31:50 +01:00
tcp_ipv4.c net/ipv4: Use nested-BH locking for ipv4_tcp_sk. 2024-06-24 16:41:22 -07:00
tcp_lp.c tcp: rename tcp_time_stamp() to tcp_time_stamp_ts() 2023-10-23 09:35:01 +01:00
tcp_metrics.c tcp_metrics: validate source addr length 2024-07-01 09:40:36 +01:00
tcp_minisocks.c tcp: Don't access uninit tcp_rsk(req)->ao_keyid in tcp_create_openreq_child(). 2024-07-16 11:56:14 +02:00
tcp_nv.c
tcp_offload.c net: drop bad gso csum_start and offset in virtio_net_hdr 2024-07-30 18:34:13 -07:00
tcp_output.c net/tcp: Add tcp-md5 and tcp-ao tracepoints 2024-06-12 06:39:04 +01:00
tcp_plb.c
tcp_rate.c
tcp_recovery.c tcp: fix excessive TLP and RACK timeouts from HZ rounding 2023-10-17 17:25:42 -07:00
tcp_scalable.c
tcp_sigpool.c net/tcp_sigpool: Use nested-BH locking for sigpool_scratch. 2024-06-24 16:41:22 -07:00
tcp_timer.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-07-11 12:58:13 -07:00
tcp_ulp.c
tcp_vegas.c
tcp_vegas.h
tcp_veno.c
tcp_westwood.c
tcp_yeah.c
tcp.c net/tcp: Remove tcp_hash_fail() 2024-06-12 06:39:04 +01:00
tunnel4.c net: fill in MODULE_DESCRIPTION()s for ipv4 modules 2024-02-09 14:12:02 -08:00
udp_bpf.c bpf, sockmap: Fix an infinite loop error when len is 0 in tcp_bpf_recvmsg_parser() 2023-03-03 17:25:15 +01:00
udp_diag.c inet_diag: add module pointer to "struct inet_diag_handler" 2024-01-23 15:13:54 +01:00
udp_impl.h sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES) 2023-06-24 15:50:13 -07:00
udp_offload.c net: drop bad gso csum_start and offset in virtio_net_hdr 2024-07-30 18:34:13 -07:00
udp_tunnel_core.c ip_tunnel: convert __be16 tunnel flags to bitmaps 2024-04-01 10:49:28 +01:00
udp_tunnel_nic.c udp_tunnel: Use flex array to simplify code 2023-10-03 11:39:34 +02:00
udp_tunnel_stub.c
udp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-07-11 12:58:13 -07:00
udplite.c udplite: remove UDPLITE_BIT 2023-09-14 16:16:36 +02:00
xfrm4_input.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-05-09 10:01:01 -07:00
xfrm4_output.c
xfrm4_policy.c net: ipv{6,4}: Remove the now superfluous sentinel elements from ctl_table array 2024-05-03 13:29:42 +01:00
xfrm4_protocol.c
xfrm4_state.c
xfrm4_tunnel.c net: fill in MODULE_DESCRIPTION()s for ipv4 modules 2024-02-09 14:12:02 -08:00