linux-stable.git/net/netfilter, branch v5.2.9

netfilter: nf_tables: Support auto-loading for inet nat

2019-08-16T08:11:00+00:00

[ Upstream commit b4f1483cbfa5fafca4874e90063f75603edbc210 ]

Trying to create an inet family nat chain would not cause
nft_chain_nat.ko module to auto-load due to missing module alias. Add a
proper one with hard-coded family value 1 for the pseudo-family
NFPROTO_INET.

Fixes: d164385ec572 ("netfilter: nat: add inet family nat support")
Signed-off-by: Phil Sutter 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nft_hash: fix symhash with modulus one

2019-08-16T08:10:59+00:00

[ Upstream commit 28b1d6ef53e3303b90ca8924bb78f31fa527cafb ]

The rule below doesn't work as the kernel raises -ERANGE.

nft add rule netdev nftlb lb01 ip daddr set \
	symhash mod 1 map { 0 : 192.168.0.10 } fwd to "eth0"

This patch allows to use the symhash modulus with one
element, in the same way that the other types of hashes and
algorithms that uses the modulus parameter.

Signed-off-by: Laura Garcia Liebana 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: conntrack: always store window size un-scaled

2019-08-16T08:10:59+00:00

[ Upstream commit 959b69ef57db00cb33e9c4777400ae7183ebddd3 ]

Jakub Jankowski reported following oddity:

After 3 way handshake completes, timeout of new connection is set to
max_retrans (300s) instead of established (5 days).

shortened excerpt from pcap provided:
25.070622 IP (flags [DF], proto TCP (6), length 52)
10.8.5.4.1025 > 10.8.1.2.80: Flags [S], seq 11, win 64240, [wscale 8]
26.070462 IP (flags [DF], proto TCP (6), length 48)
10.8.1.2.80 > 10.8.5.4.1025: Flags [S.], seq 82, ack 12, win 65535, [wscale 3]
27.070449 IP (flags [DF], proto TCP (6), length 40)
10.8.5.4.1025 > 10.8.1.2.80: Flags [.], ack 83, win 512, length 0

Turns out the last_win is of u16 type, but we store the scaled value:
512 << 8 (== 0x20000) becomes 0 window.

The Fixes tag is not correct, as the bug has existed forever, but
without that change all that this causes might cause is to mistake a
window update (to-nonzero-from-zero) for a retransmit.

Fixes: fbcd253d2448b8 ("netfilter: conntrack: lower timeout to RETRANS seconds if window is 0")
Reported-by: Jakub Jankowski 
Tested-by: Jakub Jankowski 
Signed-off-by: Florian Westphal 
Acked-by: Jozsef Kadlecsik 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nf_tables: fix module autoload for redir

2019-08-16T08:10:59+00:00

[ Upstream commit f41828ee10b36644bb2b2bfa9dd1d02f55aa0516 ]

Fix expression for autoloading.

Fixes: 5142967ab524 ("netfilter: nf_tables: fix module autoload with inet family")
Signed-off-by: Christian Hesse 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nfnetlink: avoid deadlock due to synchronous request_module

2019-08-16T08:10:58+00:00

[ Upstream commit 1b0890cd60829bd51455dc5ad689ed58c4408227 ]

Thomas and Juliana report a deadlock when running:

(rmmod nf_conntrack_netlink/xfrm_user)

  conntrack -e NEW -E &
  modprobe -v xfrm_user

They provided following analysis:

conntrack -e NEW -E
    netlink_bind()
        netlink_lock_table() -> increases "nl_table_users"
            nfnetlink_bind()
            # does not unlock the table as it's locked by netlink_bind()
                __request_module()
                    call_usermodehelper_exec()

This triggers "modprobe nf_conntrack_netlink" from kernel, netlink_bind()
won't return until modprobe process is done.

"modprobe xfrm_user":
    xfrm_user_init()
        register_pernet_subsys()
            -> grab pernet_ops_rwsem
                ..
                netlink_table_grab()
                    calls schedule() as "nl_table_users" is non-zero

so modprobe is blocked because netlink_bind() increased
nl_table_users while also holding pernet_ops_rwsem.

"modprobe nf_conntrack_netlink" runs and inits nf_conntrack_netlink:
    ctnetlink_init()
        register_pernet_subsys()
            -> blocks on "pernet_ops_rwsem" thanks to xfrm_user module

both modprobe processes wait on one another -- neither can make
progress.

Switch netlink_bind() to "nowait" modprobe -- this releases the netlink
table lock, which then allows both modprobe instances to complete.

Reported-by: Thomas Jarosch 
Reported-by: Juliana Rodrigueiro 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

net: make skb_dst_force return true when dst is refcounted

2019-07-28T06:27:13+00:00

[ Upstream commit b60a77386b1d4868f72f6353d35dabe5fbe981f2 ]

netfilter did not expect that skb_dst_force() can cause skb to lose its
dst entry.

I got a bug report with a skb->dst NULL dereference in netfilter
output path.  The backtrace contains nf_reinject(), so the dst might have
been cleared when skb got queued to userspace.

Other users were fixed via
if (skb_dst(skb)) {
	skb_dst_force(skb);
	if (!skb_dst(skb))
		goto handle_err;
}

But I think its preferable to make the 'dst might be cleared' part
of the function explicit.

In netfilter case, skb with a null dst is expected when queueing in
prerouting hook, so drop skb for the other hooks.

v2:
 v1 of this patch returned true in case skb had no dst entry.
 Eric said:
   Say if we have two skb_dst_force() calls for some reason
   on the same skb, only the first one will return false.

 This now returns false even when skb had no dst, as per Erics
 suggestion, so callers might need to check skb_dst() first before
 skb_dst_force().

Signed-off-by: Florian Westphal 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

netfilter: Fix remainder of pseudo-header protocol 0

2019-07-26T07:10:41+00:00

[ Upstream commit 5d1549847c76b1ffcf8e388ef4d0f229bdd1d7e8 ]

Since v5.1-rc1, some types of packets do not get unreachable reply with the
following iptables setting. Fox example,

$ iptables -A INPUT -p icmp --icmp-type 8 -j REJECT
$ ping 127.0.0.1 -c 1
PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data.
— 127.0.0.1 ping statistics —
1 packets transmitted, 0 received, 100% packet loss, time 0ms

We should have got the following reply from command line, but we did not.
From 127.0.0.1 icmp_seq=1 Destination Port Unreachable

Yi Zhao reported it and narrowed it down to:
7fc38225363d ("netfilter: reject: skip csum verification for protocols that don't support it"),

This is because nf_ip_checksum still expects pseudo-header protocol type 0 for
packets that are of neither TCP or UDP, and thus ICMP packets are mistakenly
treated as TCP/UDP.

This patch corrects the conditions in nf_ip_checksum and all other places that
still call it with protocol 0.

Fixes: 7fc38225363d ("netfilter: reject: skip csum verification for protocols that don't support it")
Reported-by: Yi Zhao 
Signed-off-by: He Zhe 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: ctnetlink: Fix regression in conntrack entry deletion

2019-07-26T07:10:36+00:00

[ Upstream commit e7600865db32b69deb0109b8254244dca592adcf ]

Commit f8e608982022 ("netfilter: ctnetlink: Resolve conntrack
L3-protocol flush regression") introduced a regression in which deletion
of conntrack entries would fail because the L3 protocol information
is replaced by AF_UNSPEC. As a result the search for the entry to be
deleted would turn up empty due to the tuple used to perform the search
is now different from the tuple used to initially set up the entry.

For flushing the conntrack table we do however want to keep the option
for nfgenmsg->version to have a non-zero value to allow for newer
user-space tools to request treatment under the new behavior. With that
it is possible to independently flush tables for a defined L3 protocol.
This was introduced with the enhancements in in commit 59c08c69c278
("netfilter: ctnetlink: Support L3 protocol-filter on flush").

Older user-space tools will retain the behavior of flushing all tables
regardless of defined L3 protocol.

Fixes: f8e608982022 ("netfilter: ctnetlink: Resolve conntrack L3-protocol flush regression")
Suggested-by: Pablo Neira Ayuso 
Signed-off-by: Felix Kaechele 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

ipvs: fix tinfo memory leak in start_sync_thread

2019-07-26T07:10:34+00:00

[ Upstream commit 5db7c8b9f9fc2aeec671ae3ca6375752c162e0e7 ]

syzkaller reports for memory leak in start_sync_thread [1]

As Eric points out, kthread may start and stop before the
threadfn function is called, so there is no chance the
data (tinfo in our case) to be released in thread.

Fix this by releasing tinfo in the controlling code instead.

[1]
BUG: memory leak
unreferenced object 0xffff8881206bf700 (size 32):
 comm "syz-executor761", pid 7268, jiffies 4294943441 (age 20.470s)
 hex dump (first 32 bytes):
   00 40 7c 09 81 88 ff ff 80 45 b8 21 81 88 ff ff  .@|......E.!....
   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
 backtrace:
   [<0000000057619e23>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline]
   [<0000000057619e23>] slab_post_alloc_hook mm/slab.h:439 [inline]
   [<0000000057619e23>] slab_alloc mm/slab.c:3326 [inline]
   [<0000000057619e23>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
   [<0000000086ce5479>] kmalloc include/linux/slab.h:547 [inline]
   [<0000000086ce5479>] start_sync_thread+0x5d2/0xe10 net/netfilter/ipvs/ip_vs_sync.c:1862
   [<000000001a9229cc>] do_ip_vs_set_ctl+0x4c5/0x780 net/netfilter/ipvs/ip_vs_ctl.c:2402
   [<00000000ece457c8>] nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
   [<00000000ece457c8>] nf_setsockopt+0x4c/0x80 net/netfilter/nf_sockopt.c:115
   [<00000000942f62d4>] ip_setsockopt net/ipv4/ip_sockglue.c:1258 [inline]
   [<00000000942f62d4>] ip_setsockopt+0x9b/0xb0 net/ipv4/ip_sockglue.c:1238
   [<00000000a56a8ffd>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2616
   [<00000000fa895401>] sock_common_setsockopt+0x38/0x50 net/core/sock.c:3130
   [<0000000095eef4cf>] __sys_setsockopt+0x98/0x120 net/socket.c:2078
   [<000000009747cf88>] __do_sys_setsockopt net/socket.c:2089 [inline]
   [<000000009747cf88>] __se_sys_setsockopt net/socket.c:2086 [inline]
   [<000000009747cf88>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2086
   [<00000000ded8ba80>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301
   [<00000000893b4ac8>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported-by: syzbot+7e2e50c8adfccd2e5041@syzkaller.appspotmail.com
Suggested-by: Eric Biggers 
Fixes: 998e7a76804b ("ipvs: Use kthread_run() instead of doing a double-fork via kernel_thread()")
Signed-off-by: Julian Anastasov 
Acked-by: Simon Horman 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

ipvs: defer hook registration to avoid leaks

2019-07-26T07:10:32+00:00

[ Upstream commit cf47a0b882a4e5f6b34c7949d7b293e9287f1972 ]

syzkaller reports for memory leak when registering hooks [1]

As we moved the nf_unregister_net_hooks() call into
__ip_vs_dev_cleanup(), defer the nf_register_net_hooks()
call, so that hooks are allocated and freed from same
pernet_operations (ipvs_core_dev_ops).

[1]
BUG: memory leak
unreferenced object 0xffff88810acd8a80 (size 96):
 comm "syz-executor073", pid 7254, jiffies 4294950560 (age 22.250s)
 hex dump (first 32 bytes):
   02 00 00 00 00 00 00 00 50 8b bb 82 ff ff ff ff  ........P.......
   00 00 00 00 00 00 00 00 00 77 bb 82 ff ff ff ff  .........w......
 backtrace:
   [<0000000013db61f1>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline]
   [<0000000013db61f1>] slab_post_alloc_hook mm/slab.h:439 [inline]
   [<0000000013db61f1>] slab_alloc_node mm/slab.c:3269 [inline]
   [<0000000013db61f1>] kmem_cache_alloc_node_trace+0x15b/0x2a0 mm/slab.c:3597
   [<000000001a27307d>] __do_kmalloc_node mm/slab.c:3619 [inline]
   [<000000001a27307d>] __kmalloc_node+0x38/0x50 mm/slab.c:3627
   [<0000000025054add>] kmalloc_node include/linux/slab.h:590 [inline]
   [<0000000025054add>] kvmalloc_node+0x4a/0xd0 mm/util.c:431
   [<0000000050d1bc00>] kvmalloc include/linux/mm.h:637 [inline]
   [<0000000050d1bc00>] kvzalloc include/linux/mm.h:645 [inline]
   [<0000000050d1bc00>] allocate_hook_entries_size+0x3b/0x60 net/netfilter/core.c:61
   [<00000000e8abe142>] nf_hook_entries_grow+0xae/0x270 net/netfilter/core.c:128
   [<000000004b94797c>] __nf_register_net_hook+0x9a/0x170 net/netfilter/core.c:337
   [<00000000d1545cbc>] nf_register_net_hook+0x34/0xc0 net/netfilter/core.c:464
   [<00000000876c9b55>] nf_register_net_hooks+0x53/0xc0 net/netfilter/core.c:480
   [<000000002ea868e0>] __ip_vs_init+0xe8/0x170 net/netfilter/ipvs/ip_vs_core.c:2280
   [<000000002eb2d451>] ops_init+0x4c/0x140 net/core/net_namespace.c:130
   [<000000000284ec48>] setup_net+0xde/0x230 net/core/net_namespace.c:316
   [<00000000a70600fa>] copy_net_ns+0xf0/0x1e0 net/core/net_namespace.c:439
   [<00000000ff26c15e>] create_new_namespaces+0x141/0x2a0 kernel/nsproxy.c:107
   [<00000000b103dc79>] copy_namespaces+0xa1/0xe0 kernel/nsproxy.c:165
   [<000000007cc008a2>] copy_process.part.0+0x11fd/0x2150 kernel/fork.c:2035
   [<00000000c344af7c>] copy_process kernel/fork.c:1800 [inline]
   [<00000000c344af7c>] _do_fork+0x121/0x4f0 kernel/fork.c:2369

Reported-by: syzbot+722da59ccb264bc19910@syzkaller.appspotmail.com
Fixes: 719c7d563c17 ("ipvs: Fix use-after-free in ip_vs_in")
Signed-off-by: Julian Anastasov 
Acked-by: Simon Horman 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin