linux-stable.git/net/netfilter, branch v5.4.41

netfilter: nf_osf: avoid passing pointer to local var

2020-05-14T05:58:29+00:00

commit c165d57b552aaca607fa5daf3fb524a6efe3c5a3 upstream.

gcc-10 points out that a code path exists where a pointer to a stack
variable may be passed back to the caller:

net/netfilter/nfnetlink_osf.c: In function 'nf_osf_hdr_ctx_init':
cc1: warning: function may return address of local variable [-Wreturn-local-addr]
net/netfilter/nfnetlink_osf.c:171:16: note: declared here
  171 |  struct tcphdr _tcph;
      |                ^~~~~

I am not sure whether this can happen in practice, but moving the
variable declaration into the callers avoids the problem.

Fixes: 31a9c29210e2 ("netfilter: nf_osf: add struct nf_osf_hdr_ctx")
Signed-off-by: Arnd Bergmann 
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nat: never update the UDP checksum when it's 0

2020-05-14T05:58:29+00:00

commit ea64d8d6c675c0bb712689b13810301de9d8f77a upstream.

If the UDP header of a local VXLAN endpoint is NAT-ed, and the VXLAN
device has disabled UDP checksums and enabled Tx checksum offloading,
then the skb passed to udp_manip_pkt() has hdr->check == 0 (outer
checksum disabled) and skb->ip_summed == CHECKSUM_PARTIAL (inner packet
checksum offloaded).

Because of the ->ip_summed value, udp_manip_pkt() tries to update the
outer checksum with the new address and port, leading to an invalid
checksum sent on the wire, as the original null checksum obviously
didn't take the old address and port into account.

So, we can't take ->ip_summed into account in udp_manip_pkt(), as it
might not refer to the checksum we're acting on. Instead, we can base
the decision to update the UDP checksum entirely on the value of
hdr->check, because it's null if and only if checksum is disabled:

  * A fully computed checksum can't be 0, since a 0 checksum is
    represented by the CSUM_MANGLED_0 value instead.

  * A partial checksum can't be 0, since the pseudo-header always adds
    at least one non-zero value (the UDP protocol type 0x11) and adding
    more values to the sum can't make it wrap to 0 as the carry is then
    added to the wrapped number.

  * A disabled checksum uses the special value 0.

The problem seems to be there from day one, although it was probably
not visible before UDP tunnels were implemented.

Fixes: 5b1158e909ec ("[NETFILTER]: Add NAT support for nf_conntrack")
Signed-off-by: Guillaume Nault 
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nat: fix error handling upon registering inet hook

2020-05-02T06:48:52+00:00

commit b4faef1739dd1f3b3981b8bf173a2266ea86b1eb upstream.

A case of warning was reported by syzbot.

------------[ cut here ]------------
WARNING: CPU: 0 PID: 19934 at net/netfilter/nf_nat_core.c:1106
nf_nat_unregister_fn+0x532/0x5c0 net/netfilter/nf_nat_core.c:1106
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 19934 Comm: syz-executor.5 Not tainted 5.6.0-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+0x188/0x20d lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x35 kernel/panic.c:582
 report_bug+0x27b/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:175 [inline]
 fixup_bug arch/x86/kernel/traps.c:170 [inline]
 do_error_trap+0x12b/0x220 arch/x86/kernel/traps.c:267
 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:nf_nat_unregister_fn+0x532/0x5c0 net/netfilter/nf_nat_core.c:1106
Code: ff df 48 c1 ea 03 80 3c 02 00 75 75 48 8b 44 24 10 4c 89 ef 48 c7 00 00 00 00 00 e8 e8 f8 53 fb e9 4d fe ff ff e8 ee 9c 16 fb <0f> 0b e9 41 fe ff ff e8 e2 45 54 fb e9 b5 fd ff ff 48 8b 7c 24 20
RSP: 0018:ffffc90005487208 EFLAGS: 00010246
RAX: 0000000000040000 RBX: 0000000000000004 RCX: ffffc9001444a000
RDX: 0000000000040000 RSI: ffffffff865c94a2 RDI: 0000000000000005
RBP: ffff88808b5cf000 R08: ffff8880a2620140 R09: fffffbfff14bcd79
R10: ffffc90005487208 R11: fffffbfff14bcd78 R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000
 nf_nat_ipv6_unregister_fn net/netfilter/nf_nat_proto.c:1017 [inline]
 nf_nat_inet_register_fn net/netfilter/nf_nat_proto.c:1038 [inline]
 nf_nat_inet_register_fn+0xfc/0x140 net/netfilter/nf_nat_proto.c:1023
 nf_tables_register_hook net/netfilter/nf_tables_api.c:224 [inline]
 nf_tables_addchain.constprop.0+0x82e/0x13c0 net/netfilter/nf_tables_api.c:1981
 nf_tables_newchain+0xf68/0x16a0 net/netfilter/nf_tables_api.c:2235
 nfnetlink_rcv_batch+0x83a/0x1610 net/netfilter/nfnetlink.c:433
 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:543 [inline]
 nfnetlink_rcv+0x3af/0x420 net/netfilter/nfnetlink.c:561
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x6bf/0x7e0 net/socket.c:2362
 ___sys_sendmsg+0x100/0x170 net/socket.c:2416
 __sys_sendmsg+0xec/0x1b0 net/socket.c:2449
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

and to quiesce it, unregister NFPROTO_IPV6 hook instead of NFPROTO_INET
in case of failing to register NFPROTO_IPV4 hook.

Reported-by: syzbot 
Fixes: d164385ec572 ("netfilter: nat: add inet family nat support")
Cc: Florian Westphal 
Cc: Stefano Brivio 
Signed-off-by: Hillf Danton 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_tables: report EOPNOTSUPP on unsupported flags/object type

2020-04-23T08:36:19+00:00

commit d9583cdf2f38d0f526d9a8c8564dd2e35e649bc7 upstream.

EINVAL should be used for malformed netlink messages. New userspace
utility and old kernels might easily result in EINVAL when exercising
new set features, which is misleading.

Fixes: 8aeff920dcc9 ("netfilter: nf_tables: add stateful object reference to set elements")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

net: Fix CONFIG_NET_CLS_ACT=n and CONFIG_NFT_FWD_NETDEV={y, m} build

2020-04-01T09:02:18+00:00

commit 2c64605b590edadb3fb46d1ec6badb49e940b479 upstream.

net/netfilter/nft_fwd_netdev.c: In function ‘nft_fwd_netdev_eval’:
    net/netfilter/nft_fwd_netdev.c:32:10: error: ‘struct sk_buff’ has no member named ‘tc_redirected’
      pkt->skb->tc_redirected = 1;
              ^~
    net/netfilter/nft_fwd_netdev.c:33:10: error: ‘struct sk_buff’ has no member named ‘tc_from_ingress’
      pkt->skb->tc_from_ingress = 1;
              ^~

To avoid a direct dependency with tc actions from netfilter, wrap the
redirect bits around CONFIG_NET_REDIRECT and move helpers to
include/linux/skbuff.h. Turn on this toggle from the ifb driver, the
only existing client of these bits in the tree.

This patch adds skb_set_redirected() that sets on the redirected bit
on the skbuff, it specifies if the packet was redirect from ingress
and resets the timestamp (timestamp reset was originally missing in the
netfilter bugfix).

Fixes: bcfabee1afd99484 ("netfilter: nft_fwd_netdev: allow to redirect to ifb via ingress")
Reported-by: noreply@ellerman.id.au
Reported-by: Geert Uytterhoeven 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

netfilter: nft_fwd_netdev: allow to redirect to ifb via ingress

2020-04-01T09:02:10+00:00

commit bcfabee1afd99484b6ba067361b8678e28bbc065 upstream.

Set skb->tc_redirected to 1, otherwise the ifb driver drops the packet.
Set skb->tc_from_ingress to 1 to reinject the packet back to the ingress
path after leaving the ifb egress path.

This patch inconditionally sets on these two skb fields that are
meaningful to the ifb driver. The existing forward action is guaranteed
to run from ingress path.

Fixes: 39e6dea28adc ("netfilter: nf_tables: add forward expression to the netdev family")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nft_fwd_netdev: validate family and chain type

2020-04-01T09:02:10+00:00

commit 76a109fac206e158eb3c967af98c178cff738e6a upstream.

Make sure the forward action is only used from ingress.

Fixes: 39e6dea28adc ("netfilter: nf_tables: add forward expression to the netdev family")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: flowtable: reload ip{v6}h in nf_flow_tuple_ip{v6}

2020-04-01T09:02:09+00:00

commit 41e9ec5a54f95eee1a57c8d26ab70e0492548c1b upstream.

Since pskb_may_pull may change skb->data, so we need to reload ip{v6}h at
the right place.

Fixes: a908fdec3dda ("netfilter: nf_flow_table: move ipv6 offload hook code to nf_flow_table")
Fixes: 7d2086871762 ("netfilter: nf_flow_table: move ipv4 offload hook code to nf_flow_table")
Signed-off-by: Haishuang Yan 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: xt_hashlimit: unregister proc file before releasing mutex

2020-03-21T07:11:46+00:00

[ Upstream commit 99b79c3900d4627672c85d9f344b5b0f06bc2a4d ]

Before releasing the global mutex, we only unlink the hashtable
from the hash list, its proc file is still not unregistered at
this point. So syzbot could trigger a race condition where a
parallel htable_create() could register the same file immediately
after the mutex is released.

Move htable_remove_proc_entry() back to mutex protection to
fix this. And, fold htable_destroy() into htable_put() to make
the code slightly easier to understand.

Reported-and-tested-by: syzbot+d195fd3b9a364ddd6731@syzkaller.appspotmail.com
Fixes: c4a3922d2d20 ("netfilter: xt_hashlimit: reduce hashlimit_mutex scope for htable_put()")
Signed-off-by: Cong Wang 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: hashlimit: do not use indirect calls during gc

2020-03-21T07:11:46+00:00

[ Upstream commit 28b3a4270c0fc064557e409111f2a678e64b6fa7 ]

no need, just use a simple boolean to indicate we want to reap all
entries.

Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin