linux-stable.git/net/ipv4/netfilter, branch linux-4.9.y

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

2021-04-16T09:59:12+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: rpfilter: mask ecn bits before fib lookup

2021-01-30T12:27:15+00:00

commit 2e5a6266fbb11ae93c468dfecab169aca9c27b43 upstream.

RT_TOS() only masks one of the two ECN bits. Therefore rpfilter_mt()
treats Not-ECT or ECT(1) packets in a different way than those with
ECT(0) or CE.

Reproducer:

  Create two netns, connected with a veth:
  $ ip netns add ns0
  $ ip netns add ns1
  $ ip link add name veth01 netns ns0 type veth peer name veth10 netns ns1
  $ ip -netns ns0 link set dev veth01 up
  $ ip -netns ns1 link set dev veth10 up
  $ ip -netns ns0 address add 192.0.2.10/32 dev veth01
  $ ip -netns ns1 address add 192.0.2.11/32 dev veth10

  Add a route to ns1 in ns0:
  $ ip -netns ns0 route add 192.0.2.11/32 dev veth01

  In ns1, only packets with TOS 4 can be routed to ns0:
  $ ip -netns ns1 route add 192.0.2.10/32 tos 4 dev veth10

  Ping from ns0 to ns1 works regardless of the ECN bits, as long as TOS
  is 4:
  $ ip netns exec ns0 ping -Q 4 192.0.2.11   # TOS 4, Not-ECT
    ... 0% packet loss ...
  $ ip netns exec ns0 ping -Q 5 192.0.2.11   # TOS 4, ECT(1)
    ... 0% packet loss ...
  $ ip netns exec ns0 ping -Q 6 192.0.2.11   # TOS 4, ECT(0)
    ... 0% packet loss ...
  $ ip netns exec ns0 ping -Q 7 192.0.2.11   # TOS 4, CE
    ... 0% packet loss ...

  Now use iptable's rpfilter module in ns1:
  $ ip netns exec ns1 iptables-legacy -t raw -A PREROUTING -m rpfilter --invert -j DROP

  Not-ECT and ECT(1) packets still pass:
  $ ip netns exec ns0 ping -Q 4 192.0.2.11   # TOS 4, Not-ECT
    ... 0% packet loss ...
  $ ip netns exec ns0 ping -Q 5 192.0.2.11   # TOS 4, ECT(1)
    ... 0% packet loss ...

  But ECT(0) and ECN packets are dropped:
  $ ip netns exec ns0 ping -Q 6 192.0.2.11   # TOS 4, ECT(0)
    ... 100% packet loss ...
  $ ip netns exec ns0 ping -Q 7 192.0.2.11   # TOS 4, CE
    ... 100% packet loss ...

After this patch, rpfilter doesn't drop ECT(0) and CE packets anymore.

Fixes: 8f97339d3feb ("netfilter: add ipv4 reverse path filter match")
Signed-off-by: Guillaume Nault 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_conntrack_pptp: prevent buffer overflows in debug code

2020-06-03T06:16:46+00:00

commit 4c559f15efcc43b996f4da528cd7f9483aaca36d upstream.

Dan Carpenter says: "Smatch complains that the value for "cmd" comes
from the network and can't be trusted."

Add pptp_msg_name() helper function that checks for the array boundary.

Fixes: f09943fefe6b ("[NETFILTER]: nf_conntrack/nf_nat: add PPTP helper port")
Reported-by: Dan Carpenter 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: arp_tables: init netns pointer in xt_tgdtor_param struct

2020-01-23T07:19:41+00:00

commit 212e7f56605ef9688d0846db60c6c6ec06544095 upstream.

An earlier commit (1b789577f655060d98d20e,
"netfilter: arp_tables: init netns pointer in xt_tgchk_param struct")
fixed missing net initialization for arptables, but turns out it was
incomplete.  We can get a very similar struct net NULL deref during
error unwinding:

general protection fault: 0000 [#1] PREEMPT SMP KASAN
RIP: 0010:xt_rateest_put+0xa1/0x440 net/netfilter/xt_RATEEST.c:77
 xt_rateest_tg_destroy+0x72/0xa0 net/netfilter/xt_RATEEST.c:175
 cleanup_entry net/ipv4/netfilter/arp_tables.c:509 [inline]
 translate_table+0x11f4/0x1d80 net/ipv4/netfilter/arp_tables.c:587
 do_replace net/ipv4/netfilter/arp_tables.c:981 [inline]
 do_arpt_set_ctl+0x317/0x650 net/ipv4/netfilter/arp_tables.c:1461

Also init the netns pointer in xt_tgdtor_param struct.

Fixes: add67461240c1d ("netfilter: add struct net * to target parameters")
Reported-by: syzbot+91bdd8eece0f6629ec8b@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: arp_tables: init netns pointer in xt_tgchk_param struct

2020-01-14T19:04:31+00:00

commit 1b789577f655060d98d20ed0c6f9fbd469d6ba63 upstream.

We get crash when the targets checkentry function tries to make
use of the network namespace pointer for arptables.

When the net pointer got added back in 2010, only ip/ip6/ebtables were
changed to initialize it, so arptables has this set to NULL.

This isn't a problem for normal arptables because no existing
arptables target has a checkentry function that makes use of par->net.

However, direct users of the setsockopt interface can provide any
target they want as long as its registered for ARP or UNPSEC protocols.

syzkaller managed to send a semi-valid arptables rule for RATEEST target
which is enough to trigger NULL deref:

kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
RIP: xt_rateest_tg_checkentry+0x11d/0xb40 net/netfilter/xt_RATEEST.c:109
[..]
 xt_check_target+0x283/0x690 net/netfilter/x_tables.c:1019
 check_target net/ipv4/netfilter/arp_tables.c:399 [inline]
 find_check_entry net/ipv4/netfilter/arp_tables.c:422 [inline]
 translate_table+0x1005/0x1d70 net/ipv4/netfilter/arp_tables.c:572
 do_replace net/ipv4/netfilter/arp_tables.c:977 [inline]
 do_arpt_set_ctl+0x310/0x640 net/ipv4/netfilter/arp_tables.c:1456

Fixes: add67461240c1d ("netfilter: add struct net * to target parameters")
Reported-by: syzbot+d7358a458d8a81aee898@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal 
Acked-by: Cong Wang 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_tables: fix mismatch in big-endian system

2019-02-20T09:18:34+00:00

commit 10596608c4d62cb8c1c2b806debcbd32fe657e71 upstream.

Currently, there are two different methods to store an u16 integer to
the u32 data register. For example:
  u32 *dest = ®s->data[priv->dreg];
  1. *dest = 0; *(u16 *) dest = val_u16;
  2. *dest = val_u16;

For method 1, the u16 value will be stored like this, either in
big-endian or little-endian system:
  0          15           31
  +-+-+-+-+-+-+-+-+-+-+-+-+
  |   Value   |     0     |
  +-+-+-+-+-+-+-+-+-+-+-+-+

For method 2, in little-endian system, the u16 value will be the same
as listed above. But in big-endian system, the u16 value will be stored
like this:
  0          15           31
  +-+-+-+-+-+-+-+-+-+-+-+-+
  |     0     |   Value   |
  +-+-+-+-+-+-+-+-+-+-+-+-+

So later we use "memcmp(®s->data[priv->sreg], data, 2);" to do
compare in nft_cmp, nft_lookup expr ..., method 2 will get the wrong
result in big-endian system, as 0~15 bits will always be zero.

For the similar reason, when loading an u16 value from the u32 data
register, we should use "*(u16 *) sreg;" instead of "(u16)*sreg;",
the 2nd method will get the wrong value in the big-endian system.

So introduce some wrapper functions to store/load an u8 or u16
integer to/from the u32 data register, and use them in the right
place.

Signed-off-by: Liping Zhang 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Linus Walleij 
Signed-off-by: Greg Kroah-Hartman

netfilter: x_tables: set module owner for icmp(6) matches

2018-08-24T11:12:36+00:00

[ Upstream commit d376bef9c29b3c65aeee4e785fffcd97ef0a9a81 ]

nft_compat relies on xt_request_find_match to increment
refcount of the module that provides the match/target.

The (builtin) icmp matches did't set the module owner so it
was possible to rmmod ip(6)tables while icmp extensions were still in use.

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

netfilter: x_tables: initialise match/target check parameter struct

2018-07-17T09:37:54+00:00

commit c568503ef02030f169c9e19204def610a3510918 upstream.

syzbot reports following splat:

BUG: KMSAN: uninit-value in ebt_stp_mt_check+0x24b/0x450
 net/bridge/netfilter/ebt_stp.c:162
 ebt_stp_mt_check+0x24b/0x450 net/bridge/netfilter/ebt_stp.c:162
 xt_check_match+0x1438/0x1650 net/netfilter/x_tables.c:506
 ebt_check_match net/bridge/netfilter/ebtables.c:372 [inline]
 ebt_check_entry net/bridge/netfilter/ebtables.c:702 [inline]

The uninitialised access is
   xt_mtchk_param->nft_compat

... which should be set to 0.
Fix it by zeroing the struct beforehand, same for tgchk.

ip(6)tables targetinfo uses c99-style initialiser, so no change
needed there.

Reported-by: syzbot+da4494182233c23a5fcf@syzkaller.appspotmail.com
Fixes: 55917a21d0cc0 ("netfilter: x_tables: add context to know if extension runs from nft_compat")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_nat_h323: fix logical-not-parentheses warning

2018-04-08T10:12:44+00:00

commit eee6ebbac18a189ef33d25ea9b8bcae176515e49 upstream.

Clang produces the following warning:

net/ipv4/netfilter/nf_nat_h323.c:553:6: error:
logical not is only applied to the left hand side of this comparison
  [-Werror,-Wlogical-not-parentheses]
if (!set_h225_addr(skb, protoff, data, dataoff, taddr,
    ^
add parentheses after the '!' to evaluate the comparison first
add parentheses around left hand side expression to silence this warning

There's not necessarily a bug here, but it's cleaner to return early,
ex:

if (x)
  return
...

rather than:

if (x == 0)
  ...
else
  return

Also added a return code check that seemed to be missing in one
instance.

Signed-off-by: Nick Desaulniers 
Signed-off-by: Pablo Neira Ayuso 
Cc: Nathan Chancellor 
Signed-off-by: Greg Kroah-Hartman

netfilter: x_tables: pack percpu counter allocations

2018-03-18T10:18:54+00:00

commit ae0ac0ed6fcf5af3be0f63eb935f483f44a402d2 upstream.

instead of allocating each xt_counter individually, allocate 4k chunks
and then use these for counter allocation requests.

This should speed up rule evaluation by increasing data locality,
also speeds up ruleset loading because we reduce calls to the percpu
allocator.

As Eric points out we can't use PAGE_SIZE, page_allocator would fail on
arches with 64k page size.

Suggested-by: Eric Dumazet 
Signed-off-by: Florian Westphal 
Acked-by: Eric Dumazet 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman