linux-stable.git/net/bridge/netfilter, branch linux-3.16.y Linux kernel stable tree netfilter: ebtables: compat: reject all padding in matches/watchers 2020-04-28T18:03:08+00:00 Florian Westphal fw@strlen.de 2019-12-15T02:49:25+00:00 9a6c2819cb43b3844ccddb009b92b6350973ca0f commit e608f631f0ba5f1fc5ee2e260a3a35d13107cbfe upstream. syzbot reported following splat: BUG: KASAN: vmalloc-out-of-bounds in size_entry_mwt net/bridge/netfilter/ebtables.c:2063 [inline] BUG: KASAN: vmalloc-out-of-bounds in compat_copy_entries+0x128b/0x1380 net/bridge/netfilter/ebtables.c:2155 Read of size 4 at addr ffffc900004461f4 by task syz-executor267/7937 CPU: 1 PID: 7937 Comm: syz-executor267 Not tainted 5.5.0-rc1-syzkaller #0 size_entry_mwt net/bridge/netfilter/ebtables.c:2063 [inline] compat_copy_entries+0x128b/0x1380 net/bridge/netfilter/ebtables.c:2155 compat_do_replace+0x344/0x720 net/bridge/netfilter/ebtables.c:2249 compat_do_ebt_set_ctl+0x22f/0x27e net/bridge/netfilter/ebtables.c:2333 [..] Because padding isn't considered during computation of ->buf_user_offset, "total" is decremented by fewer bytes than it should. Therefore, the first part of if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry)) will pass, -- it should not have. This causes oob access: entry->next_offset is past the vmalloced size. Reject padding and check that computed user offset (sum of ebt_entry structure plus all individual matches/watchers/targets) is same value that userspace gave us as the offset of the next entry. Reported-by: syzbot+f68108fed972453a0ad4@syzkaller.appspotmail.com Fixes: 81e675c227ec ("netfilter: ebtables: add CONFIG_COMPAT support") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit e608f631f0ba5f1fc5ee2e260a3a35d13107cbfe upstream.

syzbot reported following splat:

BUG: KASAN: vmalloc-out-of-bounds in size_entry_mwt net/bridge/netfilter/ebtables.c:2063 [inline]
BUG: KASAN: vmalloc-out-of-bounds in compat_copy_entries+0x128b/0x1380 net/bridge/netfilter/ebtables.c:2155
Read of size 4 at addr ffffc900004461f4 by task syz-executor267/7937

CPU: 1 PID: 7937 Comm: syz-executor267 Not tainted 5.5.0-rc1-syzkaller #0
 size_entry_mwt net/bridge/netfilter/ebtables.c:2063 [inline]
 compat_copy_entries+0x128b/0x1380 net/bridge/netfilter/ebtables.c:2155
 compat_do_replace+0x344/0x720 net/bridge/netfilter/ebtables.c:2249
 compat_do_ebt_set_ctl+0x22f/0x27e net/bridge/netfilter/ebtables.c:2333
 [..]

Because padding isn't considered during computation of ->buf_user_offset,
"total" is decremented by fewer bytes than it should.

Therefore, the first part of

if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry))

will pass, -- it should not have.  This causes oob access:
entry->next_offset is past the vmalloced size.

Reject padding and check that computed user offset (sum of ebt_entry
structure plus all individual matches/watchers/targets) is same
value that userspace gave us as the offset of the next entry.

Reported-by: syzbot+f68108fed972453a0ad4@syzkaller.appspotmail.com
Fixes: 81e675c227ec ("netfilter: ebtables: add CONFIG_COMPAT support")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
netfilter: ebtables: convert BUG_ONs to WARN_ONs 2020-04-28T18:03:07+00:00 Florian Westphal fw@strlen.de 2018-02-19T00:24:53+00:00 d05be1d7c02a24e27966218e796fe024922dcfec commit fc6a5d0601c5ac1d02f283a46f60b87b2033e5ca upstream. All of these conditions are not fatal and should have been WARN_ONs from the get-go. Convert them to WARN_ONs and bail out. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit fc6a5d0601c5ac1d02f283a46f60b87b2033e5ca upstream.

All of these conditions are not fatal and should have
been WARN_ONs from the get-go.

Convert them to WARN_ONs and bail out.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
netfilter: ebtables: CONFIG_COMPAT: reject trailing data after last rule 2019-09-23T20:12:03+00:00 Florian Westphal fw@strlen.de 2019-05-05T16:47:33+00:00 c140ca37d8f979b0ddb721b3fc7d6e16ae1305a8 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 <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
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 <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
netfilter: ebtables: CONFIG_COMPAT: drop a bogus WARN_ON 2019-08-13T11:39:13+00:00 Florian Westphal fw@strlen.de 2019-04-14T22:43:00+00:00 de190e903119b4a86e0745efed2e0caee47bf605 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 <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
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 <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
netfilter: ebtables: handle string from userspace with care 2018-10-21T07:46:12+00:00 Paolo Abeni pabeni@redhat.com 2018-04-27T08:45:31+00:00 9257151618971b19a555c8f7dc767a6ef7198221 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 <pabeni@redhat.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
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 <pabeni@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
netfilter: bridge: ebt_among: add more missing match size checks 2018-06-16T21:22:37+00:00 Florian Westphal fw@strlen.de 2018-03-09T13:27:31+00:00 491de848db8e7a3484e03b854d7e27ad5d8d6442 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: <syzbot+bdabab6f1983a03fc009@syzkaller.appspotmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
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: <syzbot+bdabab6f1983a03fc009@syzkaller.appspotmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
netfilter: bridge: ebt_among: add missing match size checks 2018-06-16T21:22:37+00:00 Florian Westphal fw@strlen.de 2018-02-19T02:01:45+00:00 90ee942faa9d07b3d9b92f92d83948295c390600 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: <syzbot+fe0b19af568972814355@syzkaller.appspotmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
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: <syzbot+fe0b19af568972814355@syzkaller.appspotmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
netfilter: ebtables: fix erroneous reject of last rule 2018-06-16T21:21:30+00:00 Florian Westphal fw@strlen.de 2018-03-08T11:54:19+00:00 68edcec690a62dfc46c4061dab83c08573427e6b 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 <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
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 <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
netfilter: ebtables: CONFIG_COMPAT: don't trust userland offsets 2018-06-16T21:21:30+00:00 Florian Westphal fw@strlen.de 2018-02-19T00:24:15+00:00 71a00fe67dde7d2ed206a0db2a67f29fad90cc72 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: <syzbot+845a53d13171abf8bf29@syzkaller.appspotmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
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: <syzbot+845a53d13171abf8bf29@syzkaller.appspotmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Revert "netfilter: ensure number of counters is >0 in do_replace()" 2016-08-22T21:38:31+00:00 Bernhard Thaler bernhard.thaler@wvnet.at 2015-05-28T08:26:18+00:00 023c4816c24771b784adc0feb4518a7569aa859e 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 <bernhard.thaler@wvnet.at> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
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 <bernhard.thaler@wvnet.at>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>