linux-stable.git/net/bridge/netfilter, branch v3.16.78

netfilter: ebtables: CONFIG_COMPAT: reject trailing data after last rule

2019-09-23T20:12:03+00:00

commit 680f6af5337c98d116e4f127cea7845339dba8da upstream.

If userspace provides a rule blob with trailing data after last target,
we trigger a splat, then convert ruleset to 64bit format (with trailing
data), then pass that to do_replace_finish() which then returns -EINVAL.

Erroring out right away avoids the splat plus unneeded translation and
error unwind.

Fixes: 81e675c227ec ("netfilter: ebtables: add CONFIG_COMPAT support")
Reported-by: Tetsuo Handa 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

netfilter: ebtables: CONFIG_COMPAT: drop a bogus WARN_ON

2019-08-13T11:39:13+00:00

commit 7caa56f006e9d712b44f27b32520c66420d5cbc6 upstream.

It means userspace gave us a ruleset where there is some other
data after the ebtables target but before the beginning of the next rule.

Fixes: 81e675c227ec ("netfilter: ebtables: add CONFIG_COMPAT support")
Reported-by: syzbot+659574e7bcc7f7eb4df7@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

netfilter: ebtables: handle string from userspace with care

2018-10-21T07:46:12+00:00

commit 94c752f99954797da583a84c4907ff19e92550a4 upstream.

strlcpy() can't be safely used on a user-space provided string,
as it can try to read beyond the buffer's end, if the latter is
not NULL terminated.

Leveraging the above, syzbot has been able to trigger the following
splat:

BUG: KASAN: stack-out-of-bounds in strlcpy include/linux/string.h:300
[inline]
BUG: KASAN: stack-out-of-bounds in compat_mtw_from_user
net/bridge/netfilter/ebtables.c:1957 [inline]
BUG: KASAN: stack-out-of-bounds in ebt_size_mwt
net/bridge/netfilter/ebtables.c:2059 [inline]
BUG: KASAN: stack-out-of-bounds in size_entry_mwt
net/bridge/netfilter/ebtables.c:2155 [inline]
BUG: KASAN: stack-out-of-bounds in compat_copy_entries+0x96c/0x14a0
net/bridge/netfilter/ebtables.c:2194
Write of size 33 at addr ffff8801b0abf888 by task syz-executor0/4504

CPU: 0 PID: 4504 Comm: syz-executor0 Not tainted 4.17.0-rc2+ #40
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+0x1b9/0x294 lib/dump_stack.c:113
  print_address_description+0x6c/0x20b mm/kasan/report.c:256
  kasan_report_error mm/kasan/report.c:354 [inline]
  kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
  check_memory_region_inline mm/kasan/kasan.c:260 [inline]
  check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
  memcpy+0x37/0x50 mm/kasan/kasan.c:303
  strlcpy include/linux/string.h:300 [inline]
  compat_mtw_from_user net/bridge/netfilter/ebtables.c:1957 [inline]
  ebt_size_mwt net/bridge/netfilter/ebtables.c:2059 [inline]
  size_entry_mwt net/bridge/netfilter/ebtables.c:2155 [inline]
  compat_copy_entries+0x96c/0x14a0 net/bridge/netfilter/ebtables.c:2194
  compat_do_replace+0x483/0x900 net/bridge/netfilter/ebtables.c:2285
  compat_do_ebt_set_ctl+0x2ac/0x324 net/bridge/netfilter/ebtables.c:2367
  compat_nf_sockopt net/netfilter/nf_sockopt.c:144 [inline]
  compat_nf_setsockopt+0x9b/0x140 net/netfilter/nf_sockopt.c:156
  compat_ip_setsockopt+0xff/0x140 net/ipv4/ip_sockglue.c:1279
  inet_csk_compat_setsockopt+0x97/0x120 net/ipv4/inet_connection_sock.c:1041
  compat_tcp_setsockopt+0x49/0x80 net/ipv4/tcp.c:2901
  compat_sock_common_setsockopt+0xb4/0x150 net/core/sock.c:3050
  __compat_sys_setsockopt+0x1ab/0x7c0 net/compat.c:403
  __do_compat_sys_setsockopt net/compat.c:416 [inline]
  __se_compat_sys_setsockopt net/compat.c:413 [inline]
  __ia32_compat_sys_setsockopt+0xbd/0x150 net/compat.c:413
  do_syscall_32_irqs_on arch/x86/entry/common.c:323 [inline]
  do_fast_syscall_32+0x345/0xf9b arch/x86/entry/common.c:394
  entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7fb3cb9
RSP: 002b:00000000fff0c26c EFLAGS: 00000282 ORIG_RAX: 000000000000016e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000080 RSI: 0000000020000300 RDI: 00000000000005f4
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea0006c2afc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x2fffc0000000000()
raw: 02fffc0000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: 0000000000000000 ffffea0006c20101 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Fix the issue replacing the unsafe function with strscpy() and
taking care of possible errors.

Fixes: 81e675c227ec ("netfilter: ebtables: add CONFIG_COMPAT support")
Reported-and-tested-by: syzbot+4e42a04e0bc33cb6c087@syzkaller.appspotmail.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

netfilter: bridge: ebt_among: add more missing match size checks

2018-06-16T21:22:37+00:00

commit c8d70a700a5b486bfa8e5a7d33d805389f6e59f9 upstream.

ebt_among is special, it has a dynamic match size and is exempt
from the central size checks.

commit c4585a2823edf ("bridge: ebt_among: add missing match size checks")
added validation for pool size, but missed fact that the macros
ebt_among_wh_src/dst can already return out-of-bound result because
they do not check value of wh_src/dst_ofs (an offset) vs. the size
of the match that userspace gave to us.

v2:
check that offset has correct alignment.
Paolo Abeni points out that we should also check that src/dst
wormhash arrays do not overlap, and src + length lines up with
start of dst (or vice versa).
v3: compact wormhash_sizes_valid() part

NB: Fixes tag is intentionally wrong, this bug exists from day
one when match was added for 2.6 kernel. Tag is there so stable
maintainers will notice this one too.

Tested with same rules from the earlier patch.

Fixes: c4585a2823edf ("bridge: ebt_among: add missing match size checks")
Reported-by: 
Signed-off-by: Florian Westphal 
Reviewed-by: Eric Dumazet 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

netfilter: bridge: ebt_among: add missing match size checks

2018-06-16T21:22:37+00:00

commit c4585a2823edf4d1326da44d1524ecbfda26bb37 upstream.

ebt_among is special, it has a dynamic match size and is exempt
from the central size checks.

Therefore it must check that the size of the match structure
provided from userspace is sane by making sure em->match_size
is at least the minimum size of the expected structure.

The module has such a check, but its only done after accessing
a structure that might be out of bounds.

tested with: ebtables -A INPUT ... \
--among-dst fe:fe:fe:fe:fe:fe
--among-dst fe:fe:fe:fe:fe:fe --among-src fe:fe:fe:fe:ff:f,fe:fe:fe:fe:fe:fb,fe:fe:fe:fe:fc:fd,fe:fe:fe:fe:fe:fd,fe:fe:fe:fe:fe:fe
--among-src fe:fe:fe:fe:ff:f,fe:fe:fe:fe:fe:fa,fe:fe:fe:fe:fe:fd,fe:fe:fe:fe:fe:fe,fe:fe:fe:fe:fe:fe

Reported-by: 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

netfilter: ebtables: fix erroneous reject of last rule

2018-06-16T21:21:30+00:00

commit 932909d9b28d27e807ff8eecb68c7748f6701628 upstream.

The last rule in the blob has next_entry offset that is same as total size.
This made "ebtables32 -A OUTPUT -d de:ad:be:ef:01:02" fail on 64 bit kernel.

Fixes: b71812168571fa ("netfilter: ebtables: CONFIG_COMPAT: don't trust userland offsets")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

netfilter: ebtables: CONFIG_COMPAT: don't trust userland offsets

2018-06-16T21:21:30+00:00

commit b71812168571fa55e44cdd0254471331b9c4c4c6 upstream.

We need to make sure the offsets are not out of range of the
total size.
Also check that they are in ascending order.

The WARN_ON triggered by syzkaller (it sets panic_on_warn) is
changed to also bail out, no point in continuing parsing.

Briefly tested with simple ruleset of
-A INPUT --limit 1/s' --log
plus jump to custom chains using 32bit ebtables binary.

Reported-by: 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

Revert "netfilter: ensure number of counters is >0 in do_replace()"

2016-08-22T21:38:31+00:00

commit d26e2c9ffa385dd1b646f43c1397ba12af9ed431 upstream.

This partially reverts commit 1086bbe97a07 ("netfilter: ensure number of
counters is >0 in do_replace()") in net/bridge/netfilter/ebtables.c.

Setting rules with ebtables does not work any more with 1086bbe97a07 place.

There is an error message and no rules set in the end.

e.g.

~# ebtables -t nat -A POSTROUTING --src 12:34:56:78:9a:bc -j DROP
Unable to update the kernel. Two possible causes:
1. Multiple ebtables programs were executing simultaneously. The ebtables
   userspace tool doesn't by default support multiple ebtables programs
running

Reverting the ebtables part of 1086bbe97a07 makes this work again.

Signed-off-by: Bernhard Thaler 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

netfilter: ensure number of counters is >0 in do_replace()

2016-08-22T21:38:31+00:00

commit 1086bbe97a074844188c6c988fa0b1a98c3ccbb9 upstream.

After improving setsockopt() coverage in trinity, I started triggering
vmalloc failures pretty reliably from this code path:

warn_alloc_failed+0xe9/0x140
__vmalloc_node_range+0x1be/0x270
vzalloc+0x4b/0x50
__do_replace+0x52/0x260 [ip_tables]
do_ipt_set_ctl+0x15d/0x1d0 [ip_tables]
nf_setsockopt+0x65/0x90
ip_setsockopt+0x61/0xa0
raw_setsockopt+0x16/0x60
sock_common_setsockopt+0x14/0x20
SyS_setsockopt+0x71/0xd0

It turns out we don't validate that the num_counters field in the
struct we pass in from userspace is initialized.

The same problem also exists in ebtables, arptables, ipv6, and the
compat variants.

Signed-off-by: Dave Jones 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

netfilter: bridge: fix Kconfig unmet dependencies

2014-05-26T04:42:30+00:00

Before f5efc69 ("netfilter: nf_tables: Add meta expression key for
bridge interface name"), the entire net/bridge/netfilter/ directory
depended on BRIDGE_NF_EBTABLES, ie. on ebtables. However, that
directory already contained the nf_tables bridge extension that
we should allow to compile separately. In f5efc69, we tried to
generalize this by using CONFIG_BRIDGE_NETFILTER which was not a good
idea since this option already existed and it is dedicated to enable
the Netfilter bridge IP/ARP filtering.

Let's try to fix this mess by:

1) making net/bridge/netfilter/ dependent on the toplevel
   CONFIG_NETFILTER option, just like we do with the net/netfilter and
   net/ipv{4,6}/netfilter/ directories.

2) Changing 'selects' to 'depends on' NETFILTER_XTABLES for
   BRIDGE_NF_EBTABLES. I believe this problem was already before
   f5efc69:

warning: (BRIDGE_NF_EBTABLES) selects NETFILTER_XTABLES which has
unmet direct dependencies (NET && INET && NETFILTER)

3) Fix ebtables/nf_tables bridge dependencies by making NF_TABLES_BRIDGE
   and BRIDGE_NF_EBTABLES dependent on BRIDGE and NETFILTER:

warning: (NF_TABLES_BRIDGE && BRIDGE_NF_EBTABLES) selects
BRIDGE_NETFILTER which has unmet direct dependencies (NET && BRIDGE &&
NETFILTER && INET && NETFILTER_ADVANCED)

net/built-in.o: In function `br_parse_ip_options':
br_netfilter.c:(.text+0x4a5ba): undefined reference to `ip_options_compile'
br_netfilter.c:(.text+0x4a5ed): undefined reference to `ip_options_rcv_srr'
net/built-in.o: In function `br_nf_pre_routing_finish':
br_netfilter.c:(.text+0x4a8a4): undefined reference to `ip_route_input_noref'
br_netfilter.c:(.text+0x4a987): undefined reference to `ip_route_output_flow'
make: *** [vmlinux] Error 1

Reported-by: Jim Davis 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: David S. Miller