linux-stable.git/net/ipv4, branch v4.14.87

ip_tunnel: Fix name string concatenate in __ip_tunnel_create()

2018-12-08T12:03:35+00:00

commit 000ade8016400d93b4d7c89970d96b8c14773d45 upstream.

By passing a limit of 2 bytes to strncat, strncat is limited to writing
fewer bytes than what it's supposed to append to the name here.

Since the bounds are checked on the line above this, just remove the string
bounds checks entirely since they're unneeded.

Signed-off-by: Sultan Alsawaf 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: do not release socket ownership in tcp_close()

2018-12-01T08:42:51+00:00

commit 8873c064d1de579ea23412a6d3eee972593f142b 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: 67db3e4bfbc9 ("tcp: no longer hold ehash lock while calling tcp_get_info()")
Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

inet: frags: better deal with smp races

2018-11-23T07:19:27+00:00

[ Upstream commit 0d5b9311baf27bb545f187f12ecfd558220c607d ]

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: 648700f76b03 ("inet: frags: use rhashtables for reassembly units")
Signed-off-by: Eric Dumazet 
Reported-by: 배석진 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ip_tunnel: don't force DF when MTU is locked

2018-11-23T07:19:25+00:00

[ Upstream commit 16f7eb2b77b55da816c4e207f3f9440a8cafc00a ]

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 
Reviewed-by: Stefano Brivio 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net/ipv4: defensive cipso option parsing

2018-11-13T19:15:04+00:00

commit 076ed3da0c9b2f88d9157dbe7044a45641ae369e upstream.

commit 40413955ee26 ("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 
Cc: David Woodhouse 
Cc: Simon Veith 
Cc: stable@vger.kernel.org
Acked-by: Paul Moore 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipmr: fix unresolved entry dumps

2018-11-04T13:52:50+00:00

[ Upstream commit eddf016b910486d2123675a6b5fd7d64f77cdca8 ]

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 
Fixes: 8fb472c09b9d ("ipmr: improve hash scalability")
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: drop skb on failure in ip_check_defrag()

2018-11-04T13:52:50+00:00

[ Upstream commit 7de414a9dd91426318df7b63da024b2b07e53df5 ]

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 88078d98d1bb, 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: 88078d98d1bb ("net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends")
Cc: Eric Dumazet 
Signed-off-by: Cong Wang 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: udp: fix handling of CHECKSUM_COMPLETE packets

2018-11-04T13:52:49+00:00

[ Upstream commit db4f1be3ca9b0ef7330763d07bf4ace83ad6f913 ]

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: e6afc8ace6dd ("udp: remove headers from UDP packets before queueing")
Fixes: c84d949057ca ("udp: copy skb->truesize in the first cache line")
Cc: Sam Kumar 
Cc: Eric Dumazet 
Signed-off-by: Sean Tranchetti 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

xfrm: reset transport header back to network header after all input transforms ahave been applied

2018-11-04T13:52:37+00:00

[ Upstream commit bfc0698bebcb16d19ecfc89574ad4d696955e5d3 ]

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: 7785bba299a8 ("esp: Add a software GRO codepath")
Suggested-by: Steffen Klassert 
Signed-off-by: Sowmini Varadhan 
Signed-off-by: Steffen Klassert 
Signed-off-by: Sasha Levin

inet: make sure to grab rcu_read_lock before using ireq->ireq_opt

2018-10-18T07:16:21+00:00

[ Upstream commit 2ab2ddd301a22ca3c5f0b743593e4ad2953dfa53 ]

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: 1ad98e9d1bdf ("tcp/dccp: fix lockdep issue when SYN is backlogged")
Signed-off-by: Eric Dumazet 
Reported-by: Willem de Bruijn 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman