linux-stable.git/net/netfilter, branch v5.4.115

netfilter: nft_limit: avoid possible divide error in nft_limit_init

2021-04-21T10:56:17+00:00

commit b895bdf5d643b6feb7c60856326dd4feb6981560 upstream.

div_u64() divides u64 by u32.

nft_limit_init() wants to divide u64 by u64, use the appropriate
math function (div64_u64)

divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 8390 Comm: syz-executor188 Not tainted 5.12.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:div_u64_rem include/linux/math64.h:28 [inline]
RIP: 0010:div_u64 include/linux/math64.h:127 [inline]
RIP: 0010:nft_limit_init+0x2a2/0x5e0 net/netfilter/nft_limit.c:85
Code: ef 4c 01 eb 41 0f 92 c7 48 89 de e8 38 a5 22 fa 4d 85 ff 0f 85 97 02 00 00 e8 ea 9e 22 fa 4c 0f af f3 45 89 ed 31 d2 4c 89 f0 <49> f7 f5 49 89 c6 e8 d3 9e 22 fa 48 8d 7d 48 48 b8 00 00 00 00 00
RSP: 0018:ffffc90009447198 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000200000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff875152e6 RDI: 0000000000000003
RBP: ffff888020f80908 R08: 0000200000000000 R09: 0000000000000000
R10: ffffffff875152d8 R11: 0000000000000000 R12: ffffc90009447270
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  000000000097a300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200001c4 CR3: 0000000026a52000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 nf_tables_newexpr net/netfilter/nf_tables_api.c:2675 [inline]
 nft_expr_init+0x145/0x2d0 net/netfilter/nf_tables_api.c:2713
 nft_set_elem_expr_alloc+0x27/0x280 net/netfilter/nf_tables_api.c:5160
 nf_tables_newset+0x1997/0x3150 net/netfilter/nf_tables_api.c:4321
 nfnetlink_rcv_batch+0x85a/0x21b0 net/netfilter/nfnetlink.c:456
 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:580 [inline]
 nfnetlink_rcv+0x3af/0x420 net/netfilter/nfnetlink.c:598
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Fixes: c26844eda9d4 ("netfilter: nf_tables: Fix nft limit burst handling")
Fixes: 3e0f64b7dd31 ("netfilter: nft_limit: fix packet ratelimiting")
Signed-off-by: Eric Dumazet 
Diagnosed-by: Luigi Rizzo 
Reported-by: syzbot 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: conntrack: do not print icmpv6 as unknown via /proc

2021-04-21T10:56:16+00:00

commit fbea31808ca124dd73ff6bb1e67c9af4607c3e32 upstream.

/proc/net/nf_conntrack shows icmpv6 as unknown.

Fixes: 09ec82f5af99 ("netfilter: conntrack: remove protocol name from l4proto struct")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: x_tables: fix compat match/target pad out-of-bound write

2021-04-16T09:46:38+00:00

commit b29c457a6511435960115c0f548c4360d5f4801d upstream.

xt_compat_match/target_from_user doesn't check that zeroing the area
to start of next rule won't write past end of allocated ruleset blob.

Remove this code and zero the entire blob beforehand.

Reported-by: syzbot+cfc0247ac173f597aaaa@syzkaller.appspotmail.com
Reported-by: Andy Nguyen 
Fixes: 9fa492cdc160c ("[NETFILTER]: x_tables: simplify compat API")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: conntrack: Fix gre tunneling over ipv6

2021-04-10T11:34:31+00:00

[ Upstream commit 8b2030b4305951f44afef80225f1475618e25a73 ]

This fix permits gre connections to be tracked within ip6tables rules

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

netfilter: x_tables: Use correct memory barriers.

2021-03-30T12:35:28+00:00

[ Upstream commit 175e476b8cdf2a4de7432583b49c871345e4f8a1 ]

When a new table value was assigned, it was followed by a write memory
barrier. This ensured that all writes before this point would complete
before any writes after this point. However, to determine whether the
rules are unused, the sequence counter is read. To ensure that all
writes have been done before these reads, a full memory barrier is
needed, not just a write memory barrier. The same argument applies when
incrementing the counter, before the rules are read.

Changing to using smp_mb() instead of smp_wmb() fixes the kernel panic
reported in cc00bcaa5899 (which is still present), while still
maintaining the same speed of replacing tables.

The smb_mb() barriers potentially slow the packet path, however testing
has shown no measurable change in performance on a 4-core MIPS64
platform.

Fixes: 7f5c6d4f665b ("netfilter: get rid of atomic ops in fast path")
Signed-off-by: Mark Tomlinson 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

Revert "netfilter: x_tables: Switch synchronization to RCU"

2021-03-30T12:35:28+00:00

[ Upstream commit d3d40f237480abf3268956daf18cdc56edd32834 ]

This reverts commit cc00bcaa589914096edef7fb87ca5cee4a166b5c.

This (and the preceding) patch basically re-implemented the RCU
mechanisms of patch 784544739a25. That patch was replaced because of the
performance problems that it created when replacing tables. Now, we have
the same issue: the call to synchronize_rcu() makes replacing tables
slower by as much as an order of magnitude.

Prior to using RCU a script calling "iptables" approx. 200 times was
taking 1.16s. With RCU this increased to 11.59s.

Revert these patches and fix the issue in a different way.

Signed-off-by: Mark Tomlinson 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: ctnetlink: fix dump of the expect mask attribute

2021-03-30T12:35:26+00:00

[ Upstream commit b58f33d49e426dc66e98ed73afb5d97b15a25f2d ]

Before this change, the mask is never included in the netlink message, so
"conntrack -E expect" always prints 0.0.0.0.

In older kernels the l3num callback struct was passed as argument, based
on tuple->src.l3num. After the l3num indirection got removed, the call
chain is based on m.src.l3num, but this value is 0xffff.

Init l3num to the correct value.

Fixes: f957be9d349a3 ("netfilter: conntrack: remove ctnetlink callbacks from l3 protocol trackers")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: x_tables: gpf inside xt_find_revision()

2021-03-17T16:03:32+00:00

commit 8e24edddad152b998b37a7f583175137ed2e04a5 upstream.

nested target/match_revfn() calls work with xt[NFPROTO_UNSPEC] lists
without taking xt[NFPROTO_UNSPEC].mutex. This can race with module unload
and cause host to crash:

general protection fault: 0000 [#1]
Modules linked in: ... [last unloaded: xt_cluster]
CPU: 0 PID: 542455 Comm: iptables
RIP: 0010:[]  [] strcmp+0x18/0x40
RDX: 0000000000000003 RSI: ffff9a5a5d9abe10 RDI: dead000000000111
R13: ffff9a5a5d9abe10 R14: ffff9a5a5d9abd8c R15: dead000000000100
(VvS: %R15 -- &xt_match,  %RDI -- &xt_match.name,
xt_cluster unregister match in xt[NFPROTO_UNSPEC].match list)
Call Trace:
 [] match_revfn+0x54/0xc0
 [] match_revfn+0xaf/0xc0
 [] xt_find_revision+0x6e/0xf0
 [] do_ipt_get_ctl+0x100/0x420 [ip_tables]
 [] nf_getsockopt+0x4f/0x70
 [] ip_getsockopt+0xde/0x100
 [] raw_getsockopt+0x25/0x50
 [] sock_common_getsockopt+0x1a/0x20
 [] SyS_getsockopt+0x7d/0xf0
 [] system_call_fastpath+0x25/0x2a

Fixes: 656caff20e1 ("netfilter 04/09: x_tables: fix match/target revision lookup")
Signed-off-by: Vasily Averin 
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_nat: undo erroneous tcp edemux lookup

2021-03-17T16:03:32+00:00

commit 03a3ca37e4c6478e3a84f04c8429dd5889e107fd upstream.

Under extremely rare conditions TCP early demux will retrieve the wrong
socket.

1. local machine establishes a connection to a remote server, S, on port
   p.

   This gives:
   laddr:lport -> S:p
   ... both in tcp and conntrack.

2. local machine establishes a connection to host H, on port p2.
   2a. TCP stack choses same laddr:lport, so we have
   laddr:lport -> H:p2 from TCP point of view.
   2b). There is a destination NAT rewrite in place, translating
        H:p2 to S:p.  This results in following conntrack entries:

   I)  laddr:lport -> S:p  (origin)  S:p -> laddr:lport (reply)
   II) laddr:lport -> H:p2 (origin)  S:p -> laddr:lport2 (reply)

   NAT engine has rewritten laddr:lport to laddr:lport2 to map
   the reply packet to the correct origin.

   When server sends SYN/ACK to laddr:lport2, the PREROUTING hook
   will undo-the SNAT transformation, rewriting IP header to
   S:p -> laddr:lport

   This causes TCP early demux to associate the skb with the TCP socket
   of the first connection.

   The INPUT hook will then reverse the DNAT transformation, rewriting
   the IP header to H:p2 -> laddr:lport.

Because packet ends up with the wrong socket, the new connection
never completes: originator stays in SYN_SENT and conntrack entry
remains in SYN_RECV until timeout, and responder retransmits SYN/ACK
until it gives up.

To resolve this, orphan the skb after the input rewrite:
Because the source IP address changed, the socket must be incorrect.
We can't move the DNAT undo to prerouting due to backwards
compatibility, doing so will make iptables/nftables rules to no longer
match the way they did.

After orphan, the packet will be handed to the next protocol layer
(tcp, udp, ...) and that will repeat the socket lookup just like as if
early demux was disabled.

Fixes: 41063e9dd1195 ("ipv4: Early TCP socket demux.")
Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1427
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: conntrack: skip identical origin tuple in same zone only

2021-02-17T09:35:17+00:00

[ Upstream commit 07998281c268592963e1cd623fe6ab0270b65ae4 ]

The origin skip check needs to re-test the zone. Else, we might skip
a colliding tuple in the reply direction.

This only occurs when using 'directional zones' where origin tuples
reside in different zones but the reply tuples share the same zone.

This causes the new conntrack entry to be dropped at confirmation time
because NAT clash resolution was elided.

Fixes: 4e35c1cb9460240 ("netfilter: nf_nat: skip nat clash resolution for same-origin entries")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin