commit 46c1e0621a upstream.
Clang warns:
net/netfilter/nf_conntrack_core.c:2068:21: warning: variable 'ctinfo' is
uninitialized when used here [-Wuninitialized]
nf_ct_set(skb, ct, ctinfo);
^~~~~~
net/netfilter/nf_conntrack_core.c:2024:2: note: variable 'ctinfo' is
declared here
enum ip_conntrack_info ctinfo;
^
1 warning generated.
nf_conntrack_update was split up into nf_conntrack_update and
__nf_conntrack_update, where the assignment of ctinfo is in
nf_conntrack_update but it is used in __nf_conntrack_update.
Pass the value of ctinfo from nf_conntrack_update to
__nf_conntrack_update so that uninitialized memory is not used
and everything works properly.
Fixes: ee04805ff5 ("netfilter: conntrack: make conntrack userspace helpers work again")
Link: https://github.com/ClangBuiltLinux/linux/issues/1039
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4c559f15ef 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: f09943fefe ("[NETFILTER]: nf_conntrack/nf_nat: add PPTP helper port")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 703acd70f2 upstream.
Restore helper data size initialization and fix memcopy of the helper
data size.
Fixes: 157ffffeb5 ("netfilter: nfnetlink_cthelper: reject too large userspace allocation requests")
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ee04805ff5 upstream.
Florian Westphal says:
"Problem is that after the helper hook was merged back into the confirm
one, the queueing itself occurs from the confirm hook, i.e. we queue
from the last netfilter callback in the hook-list.
Therefore, on return, the packet bypasses the confirm action and the
connection is never committed to the main conntrack table.
To fix this there are several ways:
1. revert the 'Fixes' commit and have a extra helper hook again.
Works, but has the drawback of adding another indirect call for
everyone.
2. Special case this: split the hooks only when userspace helper
gets added, so queueing occurs at a lower priority again,
and normal enqueue reinject would eventually call the last hook.
3. Extend the existing nf_queue ct update hook to allow a forced
confirmation (plus run the seqadj code).
This goes for 3)."
Fixes: 827318feb6 ("netfilter: conntrack: remove helper hook again")
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a164b95ad6 upstream.
If IPSET_FLAG_SKIP_SUBCOUNTER_UPDATE is set, user requested to not
update counters in sub sets. Therefore IPSET_FLAG_SKIP_COUNTER_UPDATE
must be set, not unset.
Fixes: 6e01781d1c ("netfilter: ipset: set match: add support to match the counters")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 340eaff651 ]
Expired intervals would still match and be dumped to user space until
garbage collection wiped them out. Make sure they stop matching and
disappear (from users' perspective) as soon as they expire.
Fixes: 8d8540c4f5 ("netfilter: nft_set_rbtree: add timeout support")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9ed81c8e0d ]
If the flow timer expires, the gc sets on the NF_FLOW_TEARDOWN flag.
Otherwise, the flowtable software path might race to refresh the
timeout, leaving the state machine in inconsistent state.
Fixes: c29f74e0df ("netfilter: nf_flow_table: hardware offload support")
Reported-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 54ab49fde9 ]
'rmmod nf_conntrack' can hang forever, because the netns exit
gets stuck in nf_conntrack_cleanup_net_list():
i_see_dead_people:
busy = 0;
list_for_each_entry(net, net_exit_list, exit_list) {
nf_ct_iterate_cleanup(kill_all, net, 0, 0);
if (atomic_read(&net->ct.count) != 0)
busy = 1;
}
if (busy) {
schedule();
goto i_see_dead_people;
}
When nf_ct_iterate_cleanup iterates the conntrack table, all nf_conn
structures can be found twice:
once for the original tuple and once for the conntracks reply tuple.
get_next_corpse() only calls the iterator when the entry is
in original direction -- the idea was to avoid unneeded invocations
of the iterator callback.
When support for clashing entries was added, the assumption that
all nf_conn objects are added twice, once in original, once for reply
tuple no longer holds -- NF_CLASH_BIT entries are only added in
the non-clashing reply direction.
Thus, if at least one NF_CLASH entry is in the list then
nf_conntrack_cleanup_net_list() always skips it completely.
During normal netns destruction, this causes a hang of several
seconds, until the gc worker removes the entry (NF_CLASH entries
always have a 1 second timeout).
But in the rmmod case, the gc worker has already been stopped, so
ct.count never becomes 0.
We can fix this in two ways:
1. Add a second test for CLASH_BIT and call iterator for those
entries as well, or:
2. Skip the original tuple direction and use the reply tuple.
2) is simpler, so do that.
Fixes: 6a757c07e5 ("netfilter: conntrack: allow insertion of clashing entries")
Reported-by: Chen Yi <yiche@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2c407aca64 ]
gcc-10 warns around a suspicious access to an empty struct member:
net/netfilter/nf_conntrack_core.c: In function '__nf_conntrack_alloc':
net/netfilter/nf_conntrack_core.c:1522:9: warning: array subscript 0 is outside the bounds of an interior zero-length array 'u8[0]' {aka 'unsigned char[0]'} [-Wzero-length-bounds]
1522 | memset(&ct->__nfct_init_offset[0], 0,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from net/netfilter/nf_conntrack_core.c:37:
include/net/netfilter/nf_conntrack.h:90:5: note: while referencing '__nfct_init_offset'
90 | u8 __nfct_init_offset[0];
| ^~~~~~~~~~~~~~~~~~
The code is correct but a bit unusual. Rework it slightly in a way that
does not trigger the warning, using an empty struct instead of an empty
array. There are probably more elegant ways to do this, but this is the
smallest change.
Fixes: c41884ce05 ("netfilter: conntrack: avoid zeroing timer")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c165d57b55 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: 31a9c29210 ("netfilter: nf_osf: add struct nf_osf_hdr_ctx")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ea64d8d6c6 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: 5b1158e909 ("[NETFILTER]: Add NAT support for nf_conntrack")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ef516e8625 upstream.
Stefano originally proposed to introduce this flag, users hit EOPNOTSUPP
in new binaries with old kernels when defining a set with ranges in
a concatenation.
Fixes: f3a2181e16 ("netfilter: nf_tables: Support for sets with multiple ranged fields")
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d9583cdf2f 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: 8aeff920dc ("netfilter: nf_tables: add stateful object reference to set elements")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 72239f2795 upstream.
Case a1. for overlap detection in __nft_rbtree_insert() is not a valid
one: start-after-start is not needed to detect any type of interval
overlap and it actually results in a false positive if, while
descending the tree, this is the only step we hit after starting from
the root.
This introduced a regression, as reported by Pablo, in Python tests
cases ip/ip.t and ip/numgen.t:
ip/ip.t: ERROR: line 124: add rule ip test-ip4 input ip hdrlength vmap { 0-4 : drop, 5 : accept, 6 : continue } counter: This rule should not have failed.
ip/numgen.t: ERROR: line 7: add rule ip test-ip4 pre dnat to numgen inc mod 10 map { 0-5 : 192.168.10.100, 6-9 : 192.168.20.200}: This rule should not have failed.
Drop case a1. and renumber others, so that they are a bit clearer. In
order for these diagrams to be readily understandable, a bigger rework
is probably needed, such as an ASCII art of the actual rbtree (instead
of a flattened version).
Shell script test sets/0044interval_overlap_0 should cover all
possible cases for false negatives, so I consider that test case still
sufficient after this change.
v2: Fix comments for cases a3. and b3.
Reported-by: Pablo Neira Ayuso <pablo@netfilter.org>
Fixes: 7c84d41416 ("netfilter: nft_set_rbtree: Detect partial overlaps on insertion")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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: bcfabee1af ("netfilter: nft_fwd_netdev: allow to redirect to ifb via ingress")
Reported-by: noreply@ellerman.id.au
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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: 39e6dea28a ("netfilter: nf_tables: add forward expression to the netdev family")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Make sure the forward action is only used from ingress.
Fixes: 39e6dea28a ("netfilter: nf_tables: add forward expression to the netdev family")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
...and return -ENOTEMPTY to the front-end in this case, instead of
proceeding. Currently, nft takes care of checking for these cases
and not sending them to the kernel, but if we drop the set_overlap()
call in nft we can end up in situations like:
# nft add table t
# nft add set t s '{ type inet_service ; flags interval ; }'
# nft add element t s '{ 1 - 5 }'
# nft add element t s '{ 6 - 10 }'
# nft add element t s '{ 4 - 7 }'
# nft list set t s
table ip t {
set s {
type inet_service
flags interval
elements = { 1-3, 4-5, 6-7 }
}
}
This change has the primary purpose of making the behaviour
consistent with nft_set_pipapo, but is also functional to avoid
inconsistent behaviour if userspace sends overlapping elements for
any reason.
v2: When we meet the same key data in the tree, as start element while
inserting an end element, or as end element while inserting a start
element, actually check that the existing element is active, before
resetting the overlap flag (Pablo Neira Ayuso)
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Replace negations of nft_rbtree_interval_end() with a new helper,
nft_rbtree_interval_start(), wherever this helps to visualise the
problem at hand, that is, for all the occurrences except for the
comparison against given flags in __nft_rbtree_get().
This gets especially useful in the next patch.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
...and return -ENOTEMPTY to the front-end on collision, -EEXIST if
an identical element already exists. Together with the previous patch,
element collision will now be returned to the user as -EEXIST.
Reported-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Currently, the -EEXIST return code of ->insert() callbacks is ambiguous: it
might indicate that a given element (including intervals) already exists as
such, or that the new element would clash with existing ones.
If identical elements already exist, the front-end is ignoring this without
returning error, in case NLM_F_EXCL is not set. However, if the new element
can't be inserted due an overlap, we should report this to the user.
To this purpose, allow set back-ends to return -ENOTEMPTY on collision with
existing elements, translate that to -EEXIST, and return that to userspace,
no matter if NLM_F_EXCL was set.
Reported-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nf_flow_rule_match() sets control.addr_type in key, so needs to also set
the corresponding mask. An exact match is wanted, so mask is all ones.
Fixes: c29f74e0df ("netfilter: nf_flow_table: hardware offload support")
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Freeing a flowtable with offloaded flows, the flow are deleted from
hardware but are not deleted from the flow table, leaking them,
and leaving their offload bit on.
Add a second pass of the disabled gc to delete the these flows from
the flow table before freeing it.
Fixes: c29f74e0df ("netfilter: nf_flow_table: hardware offload support")
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Since pskb_may_pull may change skb->data, so we need to reload ip{v6}h at
the right place.
Fixes: a908fdec3d ("netfilter: nf_flow_table: move ipv6 offload hook code to nf_flow_table")
Fixes: 7d20868717 ("netfilter: nf_flow_table: move ipv4 offload hook code to nf_flow_table")
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Since nf_flow_snat_port and nf_flow_snat_ip{v6} call pskb_may_pull()
which may change skb->data, so we need to reload ip{v6}h at the right
place.
Fixes: a908fdec3d ("netfilter: nf_flow_table: move ipv6 offload hook code to nf_flow_table")
Fixes: 7d20868717 ("netfilter: nf_flow_table: move ipv4 offload hook code to nf_flow_table")
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft will loop forever if the kernel doesn't support an expression:
1. nft_expr_type_get() appends the family specific name to the module list.
2. -EAGAIN is returned to nfnetlink, nfnetlink calls abort path.
3. abort path sets ->done to true and calls request_module for the
expression.
4. nfnetlink replays the batch, we end up in nft_expr_type_get() again.
5. nft_expr_type_get attempts to append family-specific name. This
one already exists on the list, so we continue
6. nft_expr_type_get adds the generic expression name to the module
list. -EAGAIN is returned, nfnetlink calls abort path.
7. abort path encounters the family-specific expression which
has 'done' set, so it gets removed.
8. abort path requests the generic expression name, sets done to true.
9. batch is replayed.
If the expression could not be loaded, then we will end up back at 1),
because the family-specific name got removed and the cycle starts again.
Note that userspace can SIGKILL the nft process to stop the cycle, but
the desired behaviour is to return an error after the generic expr name
fails to load the expression.
Fixes: eb014de4fd ("netfilter: nf_tables: autoload modules from the abort path")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add missing attribute validation for tunnel source and
destination ports to the netlink policy.
Fixes: af308b94a2 ("netfilter: nf_tables: add tunnel support")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add missing attribute validation for NFTA_PAYLOAD_CSUM_FLAGS
to the netlink policy.
Fixes: 1814096980 ("netfilter: nft_payload: layer 4 checksum adjustment for pseudoheader fields")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If hook registration fails, the hooks allocated via nft_netdev_hook_alloc
need to be freed.
We can't change the goto label to 'goto 5' -- while it does fix the memleak
it does cause a warning splat from the netfilter core (the hooks were not
registered).
Fixes: 3f0465a9ef ("netfilter: nf_tables: dynamically allocate hooks per net_device in flowtables")
Reported-by: syzbot+a2ff6fa45162a5ed4dd3@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If .next function does not change position index,
following .show function will repeat output related
to current position index.
Without patch:
# dd if=/proc/net/ip_tables_matches # original file output
conntrack
conntrack
conntrack
recent
recent
icmp
udplite
udp
tcp
0+1 records in
0+1 records out
65 bytes copied, 5.4074e-05 s, 1.2 MB/s
# dd if=/proc/net/ip_tables_matches bs=62 skip=1
dd: /proc/net/ip_tables_matches: cannot skip to specified offset
cp <<< end of last line
tcp <<< and then unexpected whole last line once again
0+1 records in
0+1 records out
7 bytes copied, 0.000102447 s, 68.3 kB/s
Cc: stable@vger.kernel.org
Fixes: 1f4aace60b ("fs/seq_file.c: simplify seq_file iteration code ...")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If .next function does not change position index,
following .show function will repeat output related
to current position index.
Without the patch:
# dd if=/proc/net/xt_recent/SSH # original file outpt
src=127.0.0.4 ttl: 0 last_seen: 6275444819 oldest_pkt: 1 6275444819
src=127.0.0.2 ttl: 0 last_seen: 6275438906 oldest_pkt: 1 6275438906
src=127.0.0.3 ttl: 0 last_seen: 6275441953 oldest_pkt: 1 6275441953
0+1 records in
0+1 records out
204 bytes copied, 6.1332e-05 s, 3.3 MB/s
Read after lseek into middle of last line (offset 140 in example below)
generates expected end of last line and then unexpected whole last line
once again
# dd if=/proc/net/xt_recent/SSH bs=140 skip=1
dd: /proc/net/xt_recent/SSH: cannot skip to specified offset
127.0.0.3 ttl: 0 last_seen: 6275441953 oldest_pkt: 1 6275441953
src=127.0.0.3 ttl: 0 last_seen: 6275441953 oldest_pkt: 1 6275441953
0+1 records in
0+1 records out
132 bytes copied, 6.2487e-05 s, 2.1 MB/s
Cc: stable@vger.kernel.org
Fixes: 1f4aace60b ("fs/seq_file.c: simplify seq_file iteration code ...")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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: c4a3922d2d ("netfilter: xt_hashlimit: reduce hashlimit_mutex scope for htable_put()")
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Phil reports that adding elements, flushing and re-adding them
right away:
nft add table t '{ set s { type ipv4_addr . inet_service; flags interval; }; }'
nft add element t s '{ 10.0.0.1 . 22-25, 10.0.0.1 . 10-20 }'
nft flush set t s
nft add element t s '{ 10.0.0.1 . 10-20, 10.0.0.1 . 22-25 }'
triggers, almost reliably, a crash like this one:
[ 71.319848] general protection fault, probably for non-canonical address 0x6f6b6e696c2e756e: 0000 [#1] PREEMPT SMP PTI
[ 71.321540] CPU: 3 PID: 1201 Comm: kworker/3:2 Not tainted 5.6.0-rc1-00377-g2bb07f4e1d861 #192
[ 71.322746] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190711_202441-buildvm-armv7-10.arm.fedoraproject.org-2.fc31 04/01/2014
[ 71.324430] Workqueue: events nf_tables_trans_destroy_work [nf_tables]
[ 71.325387] RIP: 0010:nft_set_elem_destroy+0xa5/0x110 [nf_tables]
[ 71.326164] Code: 89 d4 84 c0 74 0e 8b 77 44 0f b6 f8 48 01 df e8 41 ff ff ff 45 84 e4 74 36 44 0f b6 63 08 45 84 e4 74 2c 49 01 dc 49 8b 04 24 <48> 8b 40 38 48 85 c0 74 4f 48 89 e7 4c 8b
[ 71.328423] RSP: 0018:ffffc9000226fd90 EFLAGS: 00010282
[ 71.329225] RAX: 6f6b6e696c2e756e RBX: ffff88813ab79f60 RCX: ffff88813931b5a0
[ 71.330365] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88813ab79f9a
[ 71.331473] RBP: ffff88813ab79f60 R08: 0000000000000008 R09: 0000000000000000
[ 71.332627] R10: 000000000000021c R11: 0000000000000000 R12: ffff88813ab79fc2
[ 71.333615] R13: ffff88813b3adf50 R14: dead000000000100 R15: ffff88813931b8a0
[ 71.334596] FS: 0000000000000000(0000) GS:ffff88813bd80000(0000) knlGS:0000000000000000
[ 71.335780] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 71.336577] CR2: 000055ac683710f0 CR3: 000000013a222003 CR4: 0000000000360ee0
[ 71.337533] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 71.338557] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 71.339718] Call Trace:
[ 71.340093] nft_pipapo_destroy+0x7a/0x170 [nf_tables_set]
[ 71.340973] nft_set_destroy+0x20/0x50 [nf_tables]
[ 71.341879] nf_tables_trans_destroy_work+0x246/0x260 [nf_tables]
[ 71.342916] process_one_work+0x1d5/0x3c0
[ 71.343601] worker_thread+0x4a/0x3c0
[ 71.344229] kthread+0xfb/0x130
[ 71.344780] ? process_one_work+0x3c0/0x3c0
[ 71.345477] ? kthread_park+0x90/0x90
[ 71.346129] ret_from_fork+0x35/0x40
[ 71.346748] Modules linked in: nf_tables_set nf_tables nfnetlink 8021q [last unloaded: nfnetlink]
[ 71.348153] ---[ end trace 2eaa8149ca759bcc ]---
[ 71.349066] RIP: 0010:nft_set_elem_destroy+0xa5/0x110 [nf_tables]
[ 71.350016] Code: 89 d4 84 c0 74 0e 8b 77 44 0f b6 f8 48 01 df e8 41 ff ff ff 45 84 e4 74 36 44 0f b6 63 08 45 84 e4 74 2c 49 01 dc 49 8b 04 24 <48> 8b 40 38 48 85 c0 74 4f 48 89 e7 4c 8b
[ 71.350017] RSP: 0018:ffffc9000226fd90 EFLAGS: 00010282
[ 71.350019] RAX: 6f6b6e696c2e756e RBX: ffff88813ab79f60 RCX: ffff88813931b5a0
[ 71.350019] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88813ab79f9a
[ 71.350020] RBP: ffff88813ab79f60 R08: 0000000000000008 R09: 0000000000000000
[ 71.350021] R10: 000000000000021c R11: 0000000000000000 R12: ffff88813ab79fc2
[ 71.350022] R13: ffff88813b3adf50 R14: dead000000000100 R15: ffff88813931b8a0
[ 71.350025] FS: 0000000000000000(0000) GS:ffff88813bd80000(0000) knlGS:0000000000000000
[ 71.350026] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 71.350027] CR2: 000055ac683710f0 CR3: 000000013a222003 CR4: 0000000000360ee0
[ 71.350028] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 71.350028] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 71.350030] Kernel panic - not syncing: Fatal exception
[ 71.350412] Kernel Offset: disabled
[ 71.365922] ---[ end Kernel panic - not syncing: Fatal exception ]---
which is caused by dangling elements that have been deactivated, but
never removed.
On a flush operation, nft_pipapo_walk() walks through all the elements
in the mapping table, which are then deactivated by nft_flush_set(),
one by one, and added to the commit list for removal. Element data is
then freed.
On transaction commit, nft_pipapo_remove() is called, and failed to
remove these elements, leading to the stale references in the mapping.
The first symptom of this, revealed by KASan, is a one-byte
use-after-free in subsequent calls to nft_pipapo_walk(), which is
usually not enough to trigger a panic. When stale elements are used
more heavily, though, such as double-free via nft_pipapo_destroy()
as in Phil's case, the problem becomes more noticeable.
The issue comes from that fact that, on a flush operation,
nft_pipapo_remove() won't get the actual key data via elem->key,
elements to be deleted upon commit won't be found by the lookup via
pipapo_get(), and removal will be skipped. Key data should be fetched
via nft_set_ext_key(), instead.
Reported-by: Phil Sutter <phil@nwl.cc>
Fixes: 3c4287f620 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Jozsef Kadlecsik says:
====================
ipset patches for nf
The first one is larger than usual, but the issue could not be solved simpler.
Also, it's a resend of the patch I submitted a few days ago, with a one line
fix on top of that: the size of the comment extensions was not taken into
account at reporting the full size of the set.
- Fix "INFO: rcu detected stall in hash_xxx" reports of syzbot
by introducing region locking and using workqueue instead of timer based
gc of timed out entries in hash types of sets in ipset.
- Fix the forceadd evaluation path - the bug was also uncovered by the syzbot.
====================
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When the forceadd option is enabled, the hash:* types should find and replace
the first entry in the bucket with the new one if there are no reuseable
(deleted or timed out) entries. However, the position index was just not set
to zero and remained the invalid -1 if there were no reuseable entries.
Reported-by: syzbot+6a86565c74ebe30aea18@syzkaller.appspotmail.com
Fixes: 23c42a403a ("netfilter: ipset: Introduction of new commands and protocol version 7")
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
In the case of huge hash:* types of sets, due to the single spinlock of
a set the processing of the whole set under spinlock protection could take
too long.
There were four places where the whole hash table of the set was processed
from bucket to bucket under holding the spinlock:
- During resizing a set, the original set was locked to exclude kernel side
add/del element operations (userspace add/del is excluded by the
nfnetlink mutex). The original set is actually just read during the
resize, so the spinlocking is replaced with rcu locking of regions.
However, thus there can be parallel kernel side add/del of entries.
In order not to loose those operations a backlog is added and replayed
after the successful resize.
- Garbage collection of timed out entries was also protected by the spinlock.
In order not to lock too long, region locking is introduced and a single
region is processed in one gc go. Also, the simple timer based gc running
is replaced with a workqueue based solution. The internal book-keeping
(number of elements, size of extensions) is moved to region level due to
the region locking.
- Adding elements: when the max number of the elements is reached, the gc
was called to evict the timed out entries. The new approach is that the gc
is called just for the matching region, assuming that if the region
(proportionally) seems to be full, then the whole set does. We could scan
the other regions to check every entry under rcu locking, but for huge
sets it'd mean a slowdown at adding elements.
- Listing the set header data: when the set was defined with timeout
support, the garbage collector was called to clean up timed out entries
to get the correct element numbers and set size values. Now the set is
scanned to check non-timed out entries, without actually calling the gc
for the whole set.
Thanks to Florian Westphal for helping me to solve the SOFTIRQ-safe ->
SOFTIRQ-unsafe lock order issues during working on the patch.
Reported-by: syzbot+4b0e9d4ff3cf117837e5@syzkaller.appspotmail.com
Reported-by: syzbot+c27b8d5010f45c666ed1@syzkaller.appspotmail.com
Reported-by: syzbot+68a806795ac89df3aa1c@syzkaller.appspotmail.com
Fixes: 23c42a403a ("netfilter: ipset: Introduction of new commands and protocol version 7")
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
I originally used unlikely() in the if (match_only) clause, which
we hit on the mapping table for the last field in a set, to ensure
we avoid branching to the rest of for loop body, which is executed
more frequently.
However, Pablo reports, this is confusing as it gives the impression
that this is not a common case, and it's actually not the intended
usage of unlikely().
I couldn't observe any statistical difference in matching rates on
x864_64 and aarch64 without it, so just drop it.
Reported-by: Pablo Neira Ayuso <pablo@netfilter.org>
Fixes: 3c4287f620 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In both insertion and lookup examples, the two element pointers
of rule mapping tables were swapped. Fix that.
Reported-by: Pablo Neira Ayuso <pablo@netfilter.org>
Fixes: 3c4287f620 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch further relaxes the need to drop an skb due to a clash with
an existing conntrack entry.
Current clash resolution handles the case where the clash occurs between
two identical entries (distinct nf_conn objects with same tuples), i.e.:
Original Reply
existing: 10.2.3.4:42 -> 10.8.8.8:53 10.2.3.4:42 <- 10.0.0.6:5353
clashing: 10.2.3.4:42 -> 10.8.8.8:53 10.2.3.4:42 <- 10.0.0.6:5353
... existing handling will discard the unconfirmed clashing entry and
makes skb->_nfct point to the existing one. The skb can then be
processed normally just as if the clash would not have existed in the
first place.
For other clashes, the skb needs to be dropped.
This frequently happens with DNS resolvers that send A and AAAA queries
back-to-back when NAT rules are present that cause packets to get
different DNAT transformations applied, for example:
-m statistics --mode random ... -j DNAT --dnat-to 10.0.0.6:5353
-m statistics --mode random ... -j DNAT --dnat-to 10.0.0.7:5353
In this case the A or AAAA query is dropped which incurs a costly
delay during name resolution.
This patch also allows this collision type:
Original Reply
existing: 10.2.3.4:42 -> 10.8.8.8:53 10.2.3.4:42 <- 10.0.0.6:5353
clashing: 10.2.3.4:42 -> 10.8.8.8:53 10.2.3.4:42 <- 10.0.0.7:5353
In this case, clash is in original direction -- the reply direction
is still unique.
The change makes it so that when the 2nd colliding packet is received,
the clashing conntrack is tagged with new IPS_NAT_CLASH_BIT, gets a fixed
1 second timeout and is inserted in the reply direction only.
The entry is hidden from 'conntrack -L', it will time out quickly
and it can be early dropped because it will never progress to the
ASSURED state.
To avoid special-casing the delete code path to special case
the ORIGINAL hlist_nulls node, a new helper, "hlist_nulls_add_fake", is
added so hlist_nulls_del() will work.
Example:
CPU A: CPU B:
1. 10.2.3.4:42 -> 10.8.8.8:53 (A)
2. 10.2.3.4:42 -> 10.8.8.8:53 (AAAA)
3. Apply DNAT, reply changed to 10.0.0.6
4. 10.2.3.4:42 -> 10.8.8.8:53 (AAAA)
5. Apply DNAT, reply changed to 10.0.0.7
6. confirm/commit to conntrack table, no collisions
7. commit clashing entry
Reply comes in:
10.2.3.4:42 <- 10.0.0.6:5353 (A)
-> Finds a conntrack, DNAT is reversed & packet forwarded to 10.2.3.4:42
10.2.3.4:42 <- 10.0.0.7:5353 (AAAA)
-> Finds a conntrack, DNAT is reversed & packet forwarded to 10.2.3.4:42
The conntrack entry is deleted from table, as it has the NAT_CLASH
bit set.
In case of a retransmit from ORIGINAL dir, all further packets will get
the DNAT transformation to 10.0.0.6.
I tried to come up with other solutions but they all have worse
problems.
Alternatives considered were:
1. Confirm ct entries at allocation time, not in postrouting.
a. will cause uneccesarry work when the skb that creates the
conntrack is dropped by ruleset.
b. in case nat is applied, ct entry would need to be moved in
the table, which requires another spinlock pair to be taken.
c. breaks the 'unconfirmed entry is private to cpu' assumption:
we would need to guard all nfct->ext allocation requests with
ct->lock spinlock.
2. Make the unconfirmed list a hash table instead of a pcpu list.
Shares drawback c) of the first alternative.
3. Document this is expected and force users to rearrange their
ruleset (e.g. by using "-m cluster" instead of "-m statistics").
nft has the 'jhash' expression which can be used instead of 'numgen'.
Major drawback: doesn't fix what I consider a bug, not very realistic
and I believe its reasonable to have the existing rulesets to 'just
work'.
4. Document this is expected and force users to steer problematic
packets to the same CPU -- this would serialize the "allocate new
conntrack entry/nat table evaluation/perform nat/confirm entry", so
no race can occur. Similar drawback to 3.
Another advantage of this patch compared to 1) and 2) is that there are
no changes to the hot path; things are handled in the udp tracker and
the clash resolution path.
Cc: rcu@vger.kernel.org
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Followup patch will need a helper function with the 'clashing entries
refer to the identical tuple in both directions' resolution logic.
This patch will add another resolve_clash helper where loser_ct must
not be added to the dying list because it will be inserted into the
table.
Therefore this also moves the stat counters and dying-list insertion
of the losing ct.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
... so it can be re-used from clash resolution in followup patch.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
ctinfo is whats taken from the skb, i.e.
ct = nf_ct_get(skb, &ctinfo).
We do not pass 'ct' and instead re-fetch it from the skb.
Just do the same for both netns and ctinfo.
Also add a comment on what clash resolution is supposed to do.
While at it, one indent level can be removed.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
