commit 8873c064d1 upstream.
syzkaller was able to hit the WARN_ON(sock_owned_by_user(sk));
in tcp_close()
While a socket is being closed, it is very possible other
threads find it in rtnetlink dump.
tcp_get_info() will acquire the socket lock for a short amount
of time (slow = lock_sock_fast(sk)/unlock_sock_fast(sk, slow);),
enough to trigger the warning.
Fixes: 67db3e4bfb ("tcp: no longer hold ehash lock while calling tcp_get_info()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0d5b9311ba ]
Multiple cpus might attempt to insert a new fragment in rhashtable,
if for example RPS is buggy, as reported by 배석진 in
https://patchwork.ozlabs.org/patch/994601/
We use rhashtable_lookup_get_insert_key() instead of
rhashtable_insert_fast() to let cpus losing the race
free their own inet_frag_queue and use the one that
was inserted by another cpu.
Fixes: 648700f76b ("inet: frags: use rhashtables for reassembly units")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: 배석진 <soukjin.bae@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 16f7eb2b77 ]
The various types of tunnels running over IPv4 can ask to set the DF
bit to do PMTU discovery. However, PMTU discovery is subject to the
threshold set by the net.ipv4.route.min_pmtu sysctl, and is also
disabled on routes with "mtu lock". In those cases, we shouldn't set
the DF bit.
This patch makes setting the DF bit conditional on the route's MTU
locking state.
This issue seems to be older than git history.
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 076ed3da0c upstream.
commit 40413955ee ("Cipso: cipso_v4_optptr enter infinite loop") fixed
a possible infinite loop in the IP option parsing of CIPSO. The fix
assumes that ip_options_compile filtered out all zero length options and
that no other one-byte options beside IPOPT_END and IPOPT_NOOP exist.
While this assumption currently holds true, add explicit checks for zero
length and invalid length options to be safe for the future. Even though
ip_options_compile should have validated the options, the introduction of
new one-byte options can still confuse this code without the additional
checks.
Signed-off-by: Stefan Nuernberger <snu@amazon.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Simon Veith <sveith@amazon.de>
Cc: stable@vger.kernel.org
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit eddf016b91 ]
If the skb space ends in an unresolved entry while dumping we'll miss
some unresolved entries. The reason is due to zeroing the entry counter
between dumping resolved and unresolved mfc entries. We should just
keep counting until the whole table is dumped and zero when we move to
the next as we have a separate table counter.
Reported-by: Colin Ian King <colin.king@canonical.com>
Fixes: 8fb472c09b ("ipmr: improve hash scalability")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 7de414a9dd ]
Most callers of pskb_trim_rcsum() simply drop the skb when
it fails, however, ip_check_defrag() still continues to pass
the skb up to stack. This is suspicious.
In ip_check_defrag(), after we learn the skb is an IP fragment,
passing the skb to callers makes no sense, because callers expect
fragments are defrag'ed on success. So, dropping the skb when we
can't defrag it is reasonable.
Note, prior to commit 88078d98d1, this is not a big problem as
checksum will be fixed up anyway. After it, the checksum is not
correct on failure.
Found this during code review.
Fixes: 88078d98d1 ("net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends")
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit db4f1be3ca ]
Current handling of CHECKSUM_COMPLETE packets by the UDP stack is
incorrect for any packet that has an incorrect checksum value.
udp4/6_csum_init() will both make a call to
__skb_checksum_validate_complete() to initialize/validate the csum
field when receiving a CHECKSUM_COMPLETE packet. When this packet
fails validation, skb->csum will be overwritten with the pseudoheader
checksum so the packet can be fully validated by software, but the
skb->ip_summed value will be left as CHECKSUM_COMPLETE so that way
the stack can later warn the user about their hardware spewing bad
checksums. Unfortunately, leaving the SKB in this state can cause
problems later on in the checksum calculation.
Since the the packet is still marked as CHECKSUM_COMPLETE,
udp_csum_pull_header() will SUBTRACT the checksum of the UDP header
from skb->csum instead of adding it, leaving us with a garbage value
in that field. Once we try to copy the packet to userspace in the
udp4/6_recvmsg(), we'll make a call to skb_copy_and_csum_datagram_msg()
to checksum the packet data and add it in the garbage skb->csum value
to perform our final validation check.
Since the value we're validating is not the proper checksum, it's possible
that the folded value could come out to 0, causing us not to drop the
packet. Instead, we believe that the packet was checksummed incorrectly
by hardware since skb->ip_summed is still CHECKSUM_COMPLETE, and we attempt
to warn the user with netdev_rx_csum_fault(skb->dev);
Unfortunately, since this is the UDP path, skb->dev has been overwritten
by skb->dev_scratch and is no longer a valid pointer, so we end up
reading invalid memory.
This patch addresses this problem in two ways:
1) Do not use the dev pointer when calling netdev_rx_csum_fault()
from skb_copy_and_csum_datagram_msg(). Since this gets called
from the UDP path where skb->dev has been overwritten, we have
no way of knowing if the pointer is still valid. Also for the
sake of consistency with the other uses of
netdev_rx_csum_fault(), don't attempt to call it if the
packet was checksummed by software.
2) Add better CHECKSUM_COMPLETE handling to udp4/6_csum_init().
If we receive a packet that's CHECKSUM_COMPLETE that fails
verification (i.e. skb->csum_valid == 0), check who performed
the calculation. It's possible that the checksum was done in
software by the network stack earlier (such as Netfilter's
CONNTRACK module), and if that says the checksum is bad,
we can drop the packet immediately instead of waiting until
we try and copy it to userspace. Otherwise, we need to
mark the SKB as CHECKSUM_NONE, since the skb->csum field
no longer contains the full packet checksum after the
call to __skb_checksum_validate_complete().
Fixes: e6afc8ace6 ("udp: remove headers from UDP packets before queueing")
Fixes: c84d949057 ("udp: copy skb->truesize in the first cache line")
Cc: Sam Kumar <samanthakumar@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Sean Tranchetti <stranche@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit bfc0698beb ]
A policy may have been set up with multiple transforms (e.g., ESP
and ipcomp). In this situation, the ingress IPsec processing
iterates in xfrm_input() and applies each transform in turn,
processing the nexthdr to find any additional xfrm that may apply.
This patch resets the transport header back to network header
only after the last transformation so that subsequent xfrms
can find the correct transport header.
Fixes: 7785bba299 ("esp: Add a software GRO codepath")
Suggested-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2ab2ddd301 ]
Timer handlers do not imply rcu_read_lock(), so my recent fix
triggered a LOCKDEP warning when SYNACK is retransmit.
Lets add rcu_read_lock()/rcu_read_unlock() pairs around ireq->ireq_opt
usages instead of guessing what is done by callers, since it is
not worth the pain.
Get rid of ireq_opt_deref() helper since it hides the logic
without real benefit, since it is now a standard rcu_dereference().
Fixes: 1ad98e9d1b ("tcp/dccp: fix lockdep issue when SYN is backlogged")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 1ad98e9d1b ]
In normal SYN processing, packets are handled without listener
lock and in RCU protected ingress path.
But syzkaller is known to be able to trick us and SYN
packets might be processed in process context, after being
queued into socket backlog.
In commit 06f877d613 ("tcp/dccp: fix other lockdep splats
accessing ireq_opt") I made a very stupid fix, that happened
to work mostly because of the regular path being RCU protected.
Really the thing protecting ireq->ireq_opt is RCU read lock,
and the pseudo request refcnt is not relevant.
This patch extends what I did in commit 449809a66c ("tcp/dccp:
block BH for SYN processing") by adding an extra rcu_read_{lock|unlock}
pair in the paths that might be taken when processing SYN from
socket backlog (thus possibly in process context)
Fixes: 06f877d613 ("tcp/dccp: fix other lockdep splats accessing ireq_opt")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 7e823644b6 ]
Commit 2276f58ac5 ("udp: use a separate rx queue for packet reception")
turned static inline __skb_recv_udp() from being a trivial helper around
__skb_recv_datagram() into a UDP specific implementaion, making it
EXPORT_SYMBOL_GPL() at the same time.
There are external modules that got broken by __skb_recv_udp() not being
visible to them. Let's unbreak them by making __skb_recv_udp EXPORT_SYMBOL().
Rationale (one of those) why this is actually "technically correct" thing
to do: __skb_recv_udp() used to be an inline wrapper around
__skb_recv_datagram(), which itself (still, and correctly so, I believe)
is EXPORT_SYMBOL().
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Fixes: 2276f58ac5 ("udp: use a separate rx queue for packet reception")
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit af7d6cce53 ]
Since commit 5aad1de5ea ("ipv4: use separate genid for next hop
exceptions"), exceptions get deprecated separately from cached
routes. In particular, administrative changes don't clear PMTU anymore.
As Stefano described in commit e9fa1495d7 ("ipv6: Reflect MTU changes
on PMTU of exceptions for MTU-less routes"), the PMTU discovered before
the local MTU change can become stale:
- if the local MTU is now lower than the PMTU, that PMTU is now
incorrect
- if the local MTU was the lowest value in the path, and is increased,
we might discover a higher PMTU
Similarly to what commit e9fa1495d7 did for IPv6, update PMTU in those
cases.
If the exception was locked, the discovered PMTU was smaller than the
minimal accepted PMTU. In that case, if the new local MTU is smaller
than the current PMTU, let PMTU discovery figure out if locking of the
exception is still needed.
To do this, we need to know the old link MTU in the NETDEV_CHANGEMTU
notifier. By the time the notifier is called, dev->mtu has been
changed. This patch adds the old MTU as additional information in the
notifier structure, and a new call_netdevice_notifiers_u32() function.
Fixes: 5aad1de5ea ("ipv4: use separate genid for next hop exceptions")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2b5a921740 ]
commit 2abb7cdc0d ("udp: Add support for doing checksum
unnecessary conversion") left out the early demux path for
connected sockets. As a result IP_CMSG_CHECKSUM gives wrong
values for such socket when GRO is not enabled/available.
This change addresses the issue by moving the csum conversion to a
common helper and using such helper in both the default and the
early demux rx path.
Fixes: 2abb7cdc0d ("udp: Add support for doing checksum unnecessary conversion")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit c56cae23c6 ]
When splitting a GSO segment that consists of encapsulated packets, the
skb->mac_len of the segments can end up being set wrong, causing packet
drops in particular when using act_mirred and ifb interfaces in
combination with a qdisc that splits GSO packets.
This happens because at the time skb_segment() is called, network_header
will point to the inner header, throwing off the calculation in
skb_reset_mac_len(). The network_header is subsequently adjust by the
outer IP gso_segment handlers, but they don't set the mac_len.
Fix this by adding skb_reset_mac_len() calls to both the IPv4 and IPv6
gso_segment handlers, after they modify the network_header.
Many thanks to Eric Dumazet for his help in identifying the cause of
the bug.
Acked-by: Dave Taht <dave.taht@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 5cf4a8532c ]
According to the documentation in msg_zerocopy.rst, the SO_ZEROCOPY
flag was introduced because send(2) ignores unknown message flags and
any legacy application which was accidentally passing the equivalent of
MSG_ZEROCOPY earlier should not see any new behaviour.
Before commit f214f915e7 ("tcp: enable MSG_ZEROCOPY"), a send(2) call
which passed the equivalent of MSG_ZEROCOPY without setting SO_ZEROCOPY
would succeed. However, after that commit, it fails with -ENOBUFS. So
it appears that the SO_ZEROCOPY flag fails to fulfill its intended
purpose. Fix it.
Fixes: f214f915e7 ("tcp: enable MSG_ZEROCOPY")
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch changes the runtime behavior of IP defrag queue:
incoming in-order fragments are added to the end of the current
list/"run" of in-order fragments at the tail.
On some workloads, UDP stream performance is substantially improved:
RX: ./udp_stream -F 10 -T 2 -l 60
TX: ./udp_stream -c -H <host> -F 10 -T 5 -l 60
with this patchset applied on a 10Gbps receiver:
throughput=9524.18
throughput_units=Mbit/s
upstream (net-next):
throughput=4608.93
throughput_units=Mbit/s
Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit a4fd284a1f)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch introduces several helper functions/macros that will be
used in the follow-up patch. No runtime changes yet.
The new logic (fully implemented in the second patch) is as follows:
* Nodes in the rb-tree will now contain not single fragments, but lists
of consecutive fragments ("runs").
* At each point in time, the current "active" run at the tail is
maintained/tracked. Fragments that arrive in-order, adjacent
to the previous tail fragment, are added to this tail run without
triggering the re-balancing of the rb-tree.
* If a fragment arrives out of order with the offset _before_ the tail run,
it is inserted into the rb-tree as a single fragment.
* If a fragment arrives after the current tail fragment (with a gap),
it starts a new "tail" run, as is inserted into the rb-tree
at the end as the head of the new run.
skb->cb is used to store additional information
needed here (suggested by Eric Dumazet).
Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 353c9cb360)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We accidentally removed the parentheses here, but they are required
because '!' has higher precedence than '&'.
Fixes: fa0f527358 ("ip: use rb trees for IP frag queue.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 70837ffe30)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bffa72cf7f upstream
skb->rbnode shares space with skb->next, skb->prev and skb->tstamp
Current uses (TCP receive ofo queue and netem) need to save/restore
tstamp, while skb->dev is either NULL (TCP) or a constant for a given
queue (netem).
Since we plan using an RB tree for TCP retransmit queue to speedup SACK
processing with large BDP, this patch exchanges skb->dev and
skb->tstamp.
This saves some overhead in both TCP and netem.
v2: removes the swtstamp field from struct tcp_skb_cb
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Wei Wang <weiwan@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Geeralize private netem_rb_to_skb()
TCP rtx queue will soon be converted to rb-tree,
so we will need skb_rbtree_walk() helpers.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 18a4c0eab2)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This behavior is required in IPv6, and there is little need
to tolerate overlapping fragments in IPv4. This change
simplifies the code and eliminates potential DDoS attack vectors.
Tested: ran ip_defrag selftest (not yet available uptream).
Suggested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 7969e5c40d)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Giving an integer to proc_doulongvec_minmax() is dangerous on 64bit arches,
since linker might place next to it a non zero value preventing a change
to ip6frag_low_thresh.
ip6frag_low_thresh is not used anymore in the kernel, but we do not
want to prematuraly break user scripts wanting to change it.
Since specifying a minimal value of 0 for proc_doulongvec_minmax()
is moot, let's remove these zero values in all defrag units.
Fixes: 6e00f7dd5e ("ipv6: frags: fix /proc/sys/net/ipv6/ip6frag_low_thresh")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 3d23401283)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ip_defrag uses skb->cb[] to store the fragment offset, and unfortunately
this integer is currently in a different cache line than skb->next,
meaning that we use two cache lines per skb when finding the insertion point.
By aliasing skb->ip_defrag_offset and skb->dev, we pack all the fields
in a single cache line and save precious memory bandwidth.
Note that after the fast path added by Changli Gao in commit
d6bebca92c ("fragment: add fast path for in-order fragments")
this change wont help the fast path, since we still need
to access prev->len (2nd cache line), but will show great
benefits when slow path is entered, since we perform
a linear scan of a potentially long list.
Also, note that this potential long list is an attack vector,
we might consider also using an rb-tree there eventually.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit bf66337140)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
An skb_clone() was added in commit ec4fbd6475 ("inet: frag: release
spinlock before calling icmp_send()")
While fixing the bug at that time, it also added a very high cost
for DDOS frags, as the ICMP rate limit is applied after this
expensive operation (skb_clone() + consume_skb(), implying memory
allocations, copy, and freeing)
We can use skb_get(head) here, all we want is to make sure skb wont
be freed by another cpu.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 1eec5d5670)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some users are willing to provision huge amounts of memory to be able
to perform reassembly reasonnably well under pressure.
Current memory tracking is using one atomic_t and integers.
Switch to atomic_long_t so that 64bit arches can use more than 2GB,
without any cost for 32bit arches.
Note that this patch avoids an overflow error, if high_thresh was set
to ~2GB, since this test in inet_frag_alloc() was never true :
if (... || frag_mem_limit(nf) > nf->high_thresh)
Tested:
$ echo 16000000000 >/proc/sys/net/ipv4/ipfrag_high_thresh
<frag DDOS>
$ grep FRAG /proc/net/sockstat
FRAG: inuse 14705885 memory 16000002880
$ nstat -n ; sleep 1 ; nstat | grep Reas
IpReasmReqds 3317150 0.0
IpReasmFails 3317112 0.0
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 3e67f106f6)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This refactors ip_expire() since one indentation level is removed.
Note: in the future, we should try hard to avoid the skb_clone()
since this is a serious performance cost.
Under DDOS, the ICMP message wont be sent because of rate limits.
Fact that ip6_expire_frag_queue() does not use skb_clone() is
disturbing too. Presumably IPv6 should have the same
issue than the one we fixed in commit ec4fbd6475
("inet: frag: release spinlock before calling icmp_send()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 399d1404be)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove sum_frag_mem_limit(), ip_frag_mem() & ip6_frag_mem()
Also since we use rhashtable we can bring back the number of fragments
in "grep FRAG /proc/net/sockstat /proc/net/sockstat6" that was
removed in commit 434d305405 ("inet: frag: don't account number
of fragment queues")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 6befe4a78b)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some applications still rely on IP fragmentation, and to be fair linux
reassembly unit is not working under any serious load.
It uses static hash tables of 1024 buckets, and up to 128 items per bucket (!!!)
A work queue is supposed to garbage collect items when host is under memory
pressure, and doing a hash rebuild, changing seed used in hash computations.
This work queue blocks softirqs for up to 25 ms when doing a hash rebuild,
occurring every 5 seconds if host is under fire.
Then there is the problem of sharing this hash table for all netns.
It is time to switch to rhashtables, and allocate one of them per netns
to speedup netns dismantle, since this is a critical metric these days.
Lookup is now using RCU. A followup patch will even remove
the refcount hold/release left from prior implementation and save
a couple of atomic operations.
Before this patch, 16 cpus (16 RX queue NIC) could not handle more
than 1 Mpps frags DDOS.
After the patch, I reach 9 Mpps without any tuning, and can use up to 2GB
of storage for the fragments (exact number depends on frags being evicted
after timeout)
$ grep FRAG /proc/net/sockstat
FRAG: inuse 1966916 memory 2140004608
A followup patch will change the limits for 64bit arches.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Florian Westphal <fw@strlen.de>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Alexander Aring <alex.aring@gmail.com>
Cc: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 648700f76b)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We need to call inet_frags_init() before register_pernet_subsys(),
as a prereq for following patch ("inet: frags: use rhashtables for reassembly units")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 483a6e4fa0)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In order to simplify the API, add a pointer to struct inet_frags.
This will allow us to make things less complex.
These functions no longer have a struct inet_frags parameter :
inet_frag_destroy(struct inet_frag_queue *q /*, struct inet_frags *f */)
inet_frag_put(struct inet_frag_queue *q /*, struct inet_frags *f */)
inet_frag_kill(struct inet_frag_queue *q /*, struct inet_frags *f */)
inet_frags_exit_net(struct netns_frags *nf /*, struct inet_frags *f */)
ip6_expire_frag_queue(struct net *net, struct frag_queue *fq)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 093ba72914)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We will soon initialize one rhashtable per struct netns_frags
in inet_frags_init_net().
This patch changes the return value to eventually propagate an
error.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 787bea7748)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 037b0b86ec ]
Lets not turn the TCP ULP lookup into an arbitrary module loader as
we only intend to load ULP modules through this mechanism, not other
unrelated kernel modules:
[root@bar]# cat foo.c
#include <sys/types.h>
#include <sys/socket.h>
#include <linux/tcp.h>
#include <linux/in.h>
int main(void)
{
int sock = socket(PF_INET, SOCK_STREAM, 0);
setsockopt(sock, IPPROTO_TCP, TCP_ULP, "sctp", sizeof("sctp"));
return 0;
}
[root@bar]# gcc foo.c -O2 -Wall
[root@bar]# lsmod | grep sctp
[root@bar]# ./a.out
[root@bar]# lsmod | grep sctp
sctp 1077248 4
libcrc32c 16384 3 nf_conntrack,nf_nat,sctp
[root@bar]#
Fix it by adding module alias to TCP ULP modules, so probing module
via request_module() will be limited to tcp-ulp-[name]. The existing
modules like kTLS will load fine given tcp-ulp-tls alias, but others
will fail to load:
[root@bar]# lsmod | grep sctp
[root@bar]# ./a.out
[root@bar]# lsmod | grep sctp
[root@bar]#
Sockmap is not affected from this since it's either built-in or not.
Fixes: 734942cc4e ("tcp: ULP infrastructure")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 63cc357f7b ]
RFC 1337 says:
''Ignore RST segments in TIME-WAIT state.
If the 2 minute MSL is enforced, this fix avoids all three hazards.''
So with net.ipv4.tcp_rfc1337=1, expected behaviour is to have TIME-WAIT sk
expire rather than removing it instantly when a reset is received.
However, Linux will also re-start the TIME-WAIT timer.
This causes connect to fail when tying to re-use ports or very long
delays (until syn retry interval exceeds MSL).
packetdrill test case:
// Demonstrate bogus rearming of TIME-WAIT timer in rfc1337 mode.
`sysctl net.ipv4.tcp_rfc1337=1`
0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
0.000 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
0.000 bind(3, ..., ...) = 0
0.000 listen(3, 1) = 0
0.100 < S 0:0(0) win 29200 <mss 1460,nop,nop,sackOK,nop,wscale 7>
0.100 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 7>
0.200 < . 1:1(0) ack 1 win 257
0.200 accept(3, ..., ...) = 4
// Receive first segment
0.310 < P. 1:1001(1000) ack 1 win 46
// Send one ACK
0.310 > . 1:1(0) ack 1001
// read 1000 byte
0.310 read(4, ..., 1000) = 1000
// Application writes 100 bytes
0.350 write(4, ..., 100) = 100
0.350 > P. 1:101(100) ack 1001
// ACK
0.500 < . 1001:1001(0) ack 101 win 257
// close the connection
0.600 close(4) = 0
0.600 > F. 101:101(0) ack 1001 win 244
// Our side is in FIN_WAIT_1 & waits for ack to fin
0.7 < . 1001:1001(0) ack 102 win 244
// Our side is in FIN_WAIT_2 with no outstanding data.
0.8 < F. 1001:1001(0) ack 102 win 244
0.8 > . 102:102(0) ack 1002 win 244
// Our side is now in TIME_WAIT state, send ack for fin.
0.9 < F. 1002:1002(0) ack 102 win 244
0.9 > . 102:102(0) ack 1002 win 244
// Peer reopens with in-window SYN:
1.000 < S 1000:1000(0) win 9200 <mss 1460,nop,nop,sackOK,nop,wscale 7>
// Therefore, reply with ACK.
1.000 > . 102:102(0) ack 1002 win 244
// Peer sends RST for this ACK. Normally this RST results
// in tw socket removal, but rfc1337=1 setting prevents this.
1.100 < R 1002:1002(0) win 244
// second syn. Due to rfc1337=1 expect another pure ACK.
31.0 < S 1000:1000(0) win 9200 <mss 1460,nop,nop,sackOK,nop,wscale 7>
31.0 > . 102:102(0) ack 1002 win 244
// .. and another RST from peer.
31.1 < R 1002:1002(0) win 244
31.2 `echo no timer restart;ss -m -e -a -i -n -t -o state TIME-WAIT`
// third syn after one minute. Time-Wait socket should have expired by now.
63.0 < S 1000:1000(0) win 9200 <mss 1460,nop,nop,sackOK,nop,wscale 7>
// so we expect a syn-ack & 3whs to proceed from here on.
63.0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 7>
Without this patch, 'ss' shows restarts of tw timer and last packet is
thus just another pure ack, more than one minute later.
This restores the original code from commit 283fd6cf0be690a83
("Merge in ANK networking jumbo patch") in netdev-vger-cvs.git .
For some reason the else branch was removed/lost in 1f28b683339f7
("Merge in TCP/UDP optimizations and [..]") and timer restart became
unconditional.
Reported-by: Michal Tesar <mtesar@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 431280eebe ]
tcp uses per-cpu (and per namespace) sockets (net->ipv4.tcp_sk) internally
to send some control packets.
1) RST packets, through tcp_v4_send_reset()
2) ACK packets in SYN-RECV and TIME-WAIT state, through tcp_v4_send_ack()
These packets assert IP_DF, and also use the hashed IP ident generator
to provide an IPv4 ID number.
Geoff Alexander reported this could be used to build off-path attacks.
These packets should not be fragmented, since their size is smaller than
IPV4_MIN_MTU. Only some tunneled paths could eventually have to fragment,
regardless of inner IPID.
We really can use zero IPID, to address the flaw, and as a bonus,
avoid a couple of atomic operations in ip_idents_reserve()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Geoff Alexander <alexandg@cs.unm.edu>
Tested-by: Geoff Alexander <alexandg@cs.unm.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit e56b8ce363 ]
Attempt to make cryptic TCP seq number error messages clearer by
(1) identifying the source of the message as "TCP", (2) identifying the
errors as "seq # bug", and (3) grouping the field identifiers and values
by separating them with commas.
E.g., the following message is changed from:
recvmsg bug 2: copied 73BCB6CD seq 70F17CBE rcvnxt 73BCB9AA fl 0
WARNING: CPU: 2 PID: 1501 at /linux/net/ipv4/tcp.c:1881 tcp_recvmsg+0x649/0xb90
to:
TCP recvmsg seq # bug 2: copied 73BCB6CD, seq 70F17CBE, rcvnxt 73BCB9AA, fl 0
WARNING: CPU: 2 PID: 1501 at /linux/net/ipv4/tcp.c:2011 tcp_recvmsg+0x694/0xba0
Suggested-by: 積丹尼 Dan Jacobson <jidanni@jidanni.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit d376bef9c2 ]
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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 4672694bd4 ]
ip_frag_queue() might call pskb_pull() on one skb that
is already in the fragment queue.
We need to take care of possible truesize change, or we
might have an imbalance of the netns frags memory usage.
IPv6 is immune to this bug, because RFC5722, Section 4,
amended by Errata ID 3089 states :
When reassembling an IPv6 datagram, if
one or more its constituent fragments is determined to be an
overlapping fragment, the entire datagram (and any constituent
fragments) MUST be silently discarded.
Fixes: 158f323b98 ("net: adjust skb->truesize in pskb_expand_head()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 56e2c94f05 ]
We currently check current frags memory usage only when
a new frag queue is created. This allows attackers to first
consume the memory budget (default : 4 MB) creating thousands
of frag queues, then sending tiny skbs to exceed high_thresh
limit by 2 to 3 order of magnitude.
Note that before commit 648700f76b ("inet: frags: use rhashtables
for reassembly units"), work queue could be starved under DOS,
getting no cpu cycles.
After commit 648700f76b, only the per frag queue timer can eventually
remove an incomplete frag queue and its skbs.
Fixes: b13d3cbfb8 ("inet: frag: move eviction of queues to work queue")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jann Horn <jannh@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Peter Oskolkov <posk@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 15ecbe94a4 ]
Larry Brakmo proposal ( https://patchwork.ozlabs.org/patch/935233/
tcp: force cwnd at least 2 in tcp_cwnd_reduction) made us rethink
about our recent patch removing ~16 quick acks after ECN events.
tcp_enter_quickack_mode(sk, 1) makes sure one immediate ack is sent,
but in the case the sender cwnd was lowered to 1, we do not want
to have a delayed ack for the next packet we will receive.
Fixes: 522040ea5f ("tcp: do not aggressively quick ack after ECN events")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Neal Cardwell <ncardwell@google.com>
Cc: Lawrence Brakmo <brakmo@fb.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 522040ea5f ]
ECN signals currently forces TCP to enter quickack mode for
up to 16 (TCP_MAX_QUICKACKS) following incoming packets.
We believe this is not needed, and only sending one immediate ack
for the current packet should be enough.
This should reduce the extra load noticed in DCTCP environments,
after congestion events.
This is part 2 of our effort to reduce pure ACK packets.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9a9c9b51e5 ]
We want to add finer control of the number of ACK packets sent after
ECN events.
This patch is not changing current behavior, it only enables following
change.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
