The *_frag_reasm() functions are susceptible to miscalculating the byte
count of packet fragments in case the truesize of a head buffer changes.
The truesize member may be changed by the call to skb_unclone(), leaving
the fragment memory limit counter unbalanced even if all fragments are
processed. This miscalculation goes unnoticed as long as the network
namespace which holds the counter is not destroyed.
Should an attempt be made to destroy a network namespace that holds an
unbalanced fragment memory limit counter the cleanup of the namespace
never finishes. The thread handling the cleanup gets stuck in
inet_frags_exit_net() waiting for the percpu counter to reach zero. The
thread is usually in running state with a stacktrace similar to:
PID: 1073 TASK: ffff880626711440 CPU: 1 COMMAND: "kworker/u48:4"
#5 [ffff880621563d48] _raw_spin_lock at ffffffff815f5480
#6 [ffff880621563d48] inet_evict_bucket at ffffffff8158020b
#7 [ffff880621563d80] inet_frags_exit_net at ffffffff8158051c
#8 [ffff880621563db0] ops_exit_list at ffffffff814f5856
#9 [ffff880621563dd8] cleanup_net at ffffffff814f67c0
#10 [ffff880621563e38] process_one_work at ffffffff81096f14
It is not possible to create new network namespaces, and processes
that call unshare() end up being stuck in uninterruptible sleep state
waiting to acquire the net_mutex.
The bug was observed in the IPv6 netfilter code by Per Sundstrom.
I thank him for his analysis of the problem. The parts of this patch
that apply to IPv4 and IPv6 fragment reassembly are preemptive measures.
Signed-off-by: Jiri Wiesner <jwiesner@suse.com>
Reported-by: Per Sundstrom <per.sundstrom@redqube.se>
Acked-by: Peter Oskolkov <posk@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
register_{netdevice/inetaddr/inet6addr}_notifier may return an error
value, this patch adds the code to handle these error paths.
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Unlike ipv4 and normal ipv6 defrag, netfilter ipv6 defragmentation did
not save/restore skb->dst.
This causes oops when handling locally generated ipv6 fragments, as
output path needs a valid dst.
Reported-by: Maciej Żenczykowski <zenczykowski@gmail.com>
Fixes: 84379c9afe ("netfilter: ipv6: nf_defrag: drop skb dst before queueing")
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We configured iptables as below, which only allowed incoming data on
established connections:
iptables -t mangle -A PREROUTING -m state --state ESTABLISHED -j ACCEPT
iptables -t mangle -P PREROUTING DROP
When deleting a secondary address, current masquerade implements would
flush all conntracks on this device. All the established connections on
primary address also be deleted, then subsequent incoming data on the
connections would be dropped wrongly because it was identified as NEW
connection.
So when an address was delete, it should only flush connections related
with the address.
Signed-off-by: Tan Hu <tan.hu@zte.com.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
I see no reason for them, label or timer cannot be NULL, and if they
were, we'll crash with null deref anyway.
For skb_header_pointer failure, just set hotdrop to true and toss
such packet.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
An SKB is not on a list if skb->next is NULL.
Codify this convention into a helper function and use it
where we are dequeueing an SKB and need to mark it as such.
Signed-off-by: David S. Miller <davem@davemloft.net>
Roman reports that DHCPv6 client no longer sees replies from server
due to
ip6tables -t raw -A PREROUTING -m rpfilter --invert -j DROP
rule. We need to set the F_IFACE flag for linklocal addresses, they
are scoped per-device.
Fixes: 47b7e7f828 ("netfilter: don't set F_IFACE on ipv6 fib lookups")
Reported-by: Roman Mamedov <rm@romanrm.net>
Tested-by: Roman Mamedov <rm@romanrm.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
don't bother with pathological cases, they only waste cycles.
IPv6 requires a minimum MTU of 1280 so we should never see fragments
smaller than this (except last frag).
v3: don't use awkward "-offset + len"
v2: drop IPv4 part, which added same check w. IPV4_MIN_MTU (68).
There were concerns that there could be even smaller frags
generated by intermediate nodes, e.g. on radio networks.
Cc: Peter Oskolkov <posk@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Similar to TCP OOO RX queue, it makes sense to use rb trees to store
IP fragments, so that OOO fragments are inserted faster.
Tested:
- a follow-up patch contains a rather comprehensive ip defrag
self-test (functional)
- ran neper `udp_stream -c -H <host> -F 100 -l 300 -T 20`:
netstat --statistics
Ip:
282078937 total packets received
0 forwarded
0 incoming packets discarded
946760 incoming packets delivered
18743456 requests sent out
101 fragments dropped after timeout
282077129 reassemblies required
944952 packets reassembled ok
262734239 packet reassembles failed
(The numbers/stats above are somewhat better re:
reassemblies vs a kernel without this patchset. More
comprehensive performance testing TBD).
Reported-by: Jann Horn <jannh@google.com>
Reported-by: Juha-Matti Tilli <juha-matti.tilli@iki.fi>
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter/IPVS updates for your net-next
tree:
1) No need to set ttl from reject action for the bridge family, from
Taehee Yoo.
2) Use a fixed timeout for flow that are passed up from the flowtable
to conntrack, from Florian Westphal.
3) More preparation patches for tproxy support for nf_tables, from Mate
Eckl.
4) Remove unnecessary indirection in core IPv6 checksum function, from
Florian Westphal.
5) Use nf_ct_get_tuplepr() from openvswitch, instead of opencoding it.
From Florian Westphal.
6) socket match now selects socket infrastructure, instead of depending
on it. From Mate Eckl.
7) Patch series to simplify conntrack tuple building/parsing from packet
path and ctnetlink, from Florian Westphal.
8) Fetch timeout policy from protocol helpers, instead of doing it from
core, from Florian Westphal.
9) Merge IPv4 and IPv6 protocol trackers into conntrack core, from
Florian Westphal.
10) Depend on CONFIG_NF_TABLES_IPV6 and CONFIG_IP6_NF_IPTABLES
respectively, instead of IPV6. Patch from Mate Eckl.
11) Add specific function for garbage collection in conncount,
from Yi-Hung Wei.
12) Catch number of elements in the connlimit list, from Yi-Hung Wei.
13) Move locking to nf_conncount, from Yi-Hung Wei.
14) Series of patches to add lockless tree traversal in nf_conncount,
from Yi-Hung Wei.
15) Resolve clash in matching conntracks when race happens, from
Martynas Pumputis.
16) If connection entry times out, remove template entry from the
ip_vs_conn_tab table to improve behaviour under flood, from
Julian Anastasov.
17) Remove useless parameter from nf_ct_helper_ext_add(), from Gao feng.
18) Call abort from 2-phase commit protocol before requesting modules,
make sure this is done under the mutex, from Florian Westphal.
19) Grab module reference when starting transaction, also from Florian.
20) Dynamically allocate expression info array for pre-parsing, from
Florian.
21) Add per netns mutex for nf_tables, from Florian Westphal.
22) A couple of patches to simplify and refactor nf_osf code to prepare
for nft_osf support.
23) Break evaluation on missing socket, from Mate Eckl.
24) Allow to match socket mark from nft_socket, from Mate Eckl.
25) Remove dependency on nf_defrag_ipv6, now that IPv6 tracker is
built-in into nf_conntrack. From Florian Westphal.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
IPV6=m
DEFRAG_IPV6=m
CONNTRACK=y yields:
net/netfilter/nf_conntrack_proto.o: In function `nf_ct_netns_do_get':
net/netfilter/nf_conntrack_proto.c:802: undefined reference to `nf_defrag_ipv6_enable'
net/netfilter/nf_conntrack_proto.o:(.rodata+0x640): undefined reference to `nf_conntrack_l4proto_icmpv6'
Setting DEFRAG_IPV6=y causes undefined references to ip6_rhash_params
ip6_frag_init and ip6_expire_frag_queue so it would be needed to force
IPV6=y too.
This patch gets rid of the 'followup linker error' by removing
the dependency of ipv6.ko symbols from netfilter ipv6 defrag.
Shared code is placed into a header, then used from both.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This unifies ipv4 and ipv6 protocol trackers and removes the l3proto
abstraction.
This gets rid of all l3proto indirect calls and the need to do
a lookup on the function to call for l3 demux.
It increases module size by only a small amount (12kbyte), so this reduces
size because nf_conntrack.ko is useless without either nf_conntrack_ipv4
or nf_conntrack_ipv6 module.
before:
text data bss dec hex filename
7357 1088 0 8445 20fd nf_conntrack_ipv4.ko
7405 1084 4 8493 212d nf_conntrack_ipv6.ko
72614 13689 236 86539 1520b nf_conntrack.ko
19K nf_conntrack_ipv4.ko
19K nf_conntrack_ipv6.ko
179K nf_conntrack.ko
after:
text data bss dec hex filename
79277 13937 236 93450 16d0a nf_conntrack.ko
191K nf_conntrack.ko
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Not needed, we can have the l4trackers fetch it themselvs.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Handle it in the core instead.
ipv6_skip_exthdr() is built-in even if ipv6 is a module, i.e. this
doesn't create an ipv6 dependency.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Its simpler to just handle it directly in nf_ct_invert_tuple().
Also gets rid of need to pass l3proto pointer to resolve_conntrack().
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
handle everything from ctnetlink directly.
After all these years we still only support ipv4 and ipv6, so it
seems reasonable to remove l3 protocol tracker support and instead
handle ipv4/ipv6 from a common, always builtin inet tracker.
Step 1: Get rid of all the l3proto->func() calls.
Start with ctnetlink, then move on to packet-path ones.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Eric Dumazet reports:
Here is a reproducer of an annoying bug detected by syzkaller on our production kernel
[..]
./b78305423 enable_conntrack
Then :
sleep 60
dmesg | tail -10
[ 171.599093] unregister_netdevice: waiting for lo to become free. Usage count = 2
[ 181.631024] unregister_netdevice: waiting for lo to become free. Usage count = 2
[ 191.687076] unregister_netdevice: waiting for lo to become free. Usage count = 2
[ 201.703037] unregister_netdevice: waiting for lo to become free. Usage count = 2
[ 211.711072] unregister_netdevice: waiting for lo to become free. Usage count = 2
[ 221.959070] unregister_netdevice: waiting for lo to become free. Usage count = 2
Reproducer sends ipv6 fragment that hits nfct defrag via LOCAL_OUT hook.
skb gets queued until frag timer expiry -- 1 minute.
Normally nf_conntrack_reasm gets called during prerouting, so skb has
no dst yet which might explain why this wasn't spotted earlier.
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Reported-by: John Sperbeck <jsperbeck@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Tested-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch fixes a silent out-of-bound read possibility that was present
because of the misuse of this function.
Mostly it was called with a struct udphdr *hp which had only the udphdr
part linearized by the skb_header_pointer, however
nf_tproxy_get_sock_v{4,6} uses it as a tcphdr pointer, so some reads for
tcp specific attributes may be invalid.
Fixes: a583636a83 ("inet: refactor inet[6]_lookup functions to take skb")
Signed-off-by: Máté Eckl <ecklm94@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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 <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Simple overlapping changes in stmmac driver.
Adjust skb_gro_flush_final_remcsum function signature to make GRO list
changes in net-next, as per Stephen Rothwell's example merge
resolution.
Signed-off-by: David S. Miller <davem@davemloft.net>
Jiri Wiesner
Taehee Yoo
Florian Westphal
Tan Hu
David S. Miller
Peter Oskolkov
Máté Eckl