linux-stable.git/net/ipv4, branch v3.10.73

tcp: make connect() mem charging friendly

2015-03-26T14:00:56+00:00

[ Upstream commit 355a901e6cf1b2b763ec85caa2a9f04fbcc4ab4a ]

While working on sk_forward_alloc problems reported by Denys
Fedoryshchenko, we found that tcp connect() (and fastopen) do not call
sk_wmem_schedule() for SYN packet (and/or SYN/DATA packet), so
sk_forward_alloc is negative while connect is in progress.

We can fix this by calling regular sk_stream_alloc_skb() both for the
SYN packet (in tcp_connect()) and the syn_data packet in
tcp_send_syn_data()

Then, tcp_send_syn_data() can avoid copying syn_data as we simply
can manipulate syn_data->cb[] to remove SYN flag (and increment seq)

Instead of open coding memcpy_fromiovecend(), simply use this helper.

This leaves in socket write queue clean fast clone skbs.

This was tested against our fastopen packetdrill tests.

Reported-by: Denys Fedoryshchenko 
Signed-off-by: Eric Dumazet 
Acked-by: Yuchung Cheng 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: fix tcp fin memory accounting

2015-03-26T14:00:56+00:00

[ Upstream commit d22e1537181188e5dc8cbc51451832625035bdc2 ]

tcp_send_fin() does not account for the memory it allocates properly, so
sk_forward_alloc can be negative in cases where we've sent a FIN:

ss example output (ss -amn | grep -B1 f4294):
tcp    FIN-WAIT-1 0      1            192.168.0.1:45520         192.0.2.1:8080
	skmem:(r0,rb87380,t0,tb87380,f4294966016,w1280,o0,bl0)
Acked-by: Eric Dumazet 

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

inet_diag: fix possible overflow in inet_diag_dump_one_icsk()

2015-03-26T14:00:55+00:00

[ Upstream commit c8e2c80d7ec00d020320f905822bf49c5ad85250 ]

inet_diag_dump_one_icsk() allocates too small skb.

Add inet_sk_attr_size() helper right before inet_sk_diag_fill()
so that it can be updated if/when new attributes are added.

iproute2/ss currently does not use this dump_one() interface,
this might explain nobody noticed this problem yet.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

udp: only allow UFO for packets from SOCK_DGRAM sockets

2015-03-18T12:22:27+00:00

[ Upstream commit acf8dd0a9d0b9e4cdb597c2f74802f79c699e802 ]

If an over-MTU UDP datagram is sent through a SOCK_RAW socket to a
UFO-capable device, ip_ufo_append_data() sets skb->ip_summed to
CHECKSUM_PARTIAL unconditionally as all GSO code assumes transport layer
checksum is to be computed on segmentation. However, in this case,
skb->csum_start and skb->csum_offset are never set as raw socket
transmit path bypasses udp_send_skb() where they are usually set. As a
result, driver may access invalid memory when trying to calculate the
checksum and store the result (as observed in virtio_net driver).

Moreover, the very idea of modifying the userspace provided UDP header
is IMHO against raw socket semantics (I wasn't able to find a document
clearly stating this or the opposite, though). And while allowing
CHECKSUM_NONE in the UFO case would be more efficient, it would be a bit
too intrusive change just to handle a corner case like this. Therefore
disallowing UFO for packets from SOCK_DGRAM seems to be the best option.

Signed-off-by: Michal Kubecek 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv4: ip_check_defrag should not assume that skb_network_offset is zero

2015-03-18T12:22:26+00:00

[ Upstream commit 3e32e733d1bbb3f227259dc782ef01d5706bdae0 ]

ip_check_defrag() may be used by af_packet to defragment outgoing packets.
skb_network_offset() of af_packet's outgoing packets is not zero.

Signed-off-by: Alexander Drozdov 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv4: ip_check_defrag should correctly check return value of skb_copy_bits

2015-03-18T12:22:26+00:00

[ Upstream commit fba04a9e0c869498889b6445fd06cbe7da9bb834 ]

skb_copy_bits() returns zero on success and negative value on error,
so it is needed to invert the condition in ip_check_defrag().

Fixes: 1bf3751ec90c ("ipv4: ip_check_defrag must not modify skb before unsharing")
Signed-off-by: Alexander Drozdov 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv4: tcp: get rid of ugly unicast_sock

2015-02-27T01:48:48+00:00

[ Upstream commit bdbbb8527b6f6a358dbcb70dac247034d665b8e4 ]

In commit be9f4a44e7d41 ("ipv4: tcp: remove per net tcp_sock")
I tried to address contention on a socket lock, but the solution
I chose was horrible :

commit 3a7c384ffd57e ("ipv4: tcp: unicast_sock should not land outside
of TCP stack") addressed a selinux regression.

commit 0980e56e506b ("ipv4: tcp: set unicast_sock uc_ttl to -1")
took care of another regression.

commit b5ec8eeac46 ("ipv4: fix ip_send_skb()") fixed another regression.

commit 811230cd85 ("tcp: ipv4: initialize unicast_sock sk_pacing_rate")
was another shot in the dark.

Really, just use a proper socket per cpu, and remove the skb_orphan()
call, to re-enable flow control.

This solves a serious problem with FQ packet scheduler when used in
hostile environments, as we do not want to allocate a flow structure
for every RST packet sent in response to a spoofed packet.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: ipv4: initialize unicast_sock sk_pacing_rate

2015-02-27T01:48:48+00:00

[ Upstream commit 811230cd853d62f09ed0addd0ce9a1b9b0e13fb5 ]

When I added sk_pacing_rate field, I forgot to initialize its value
in the per cpu unicast_sock used in ip_send_unicast_reply()

This means that for sch_fq users, RST packets, or ACK packets sent
on behalf of TIME_WAIT sockets might be sent to slowly or even dropped
once we reach the per flow limit.

Signed-off-by: Eric Dumazet 
Fixes: 95bd09eb2750 ("tcp: TSO packets automatic sizing")
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ping: Fix race in free in receive path

2015-02-27T01:48:48+00:00

[ Upstream commit fc752f1f43c1c038a2c6ae58cc739ebb5953ccb0 ]

An exception is seen in ICMP ping receive path where the skb
destructor sock_rfree() tries to access a freed socket. This happens
because ping_rcv() releases socket reference with sock_put() and this
internally frees up the socket. Later icmp_rcv() will try to free the
skb and as part of this, skb destructor is called and which leads
to a kernel panic as the socket is freed already in ping_rcv().

-->|exception
-007|sk_mem_uncharge
-007|sock_rfree
-008|skb_release_head_state
-009|skb_release_all
-009|__kfree_skb
-010|kfree_skb
-011|icmp_rcv
-012|ip_local_deliver_finish

Fix this incorrect free by cloning this skb and processing this cloned
skb instead.

This patch was suggested by Eric Dumazet

Signed-off-by: Subash Abhinov Kasiviswanathan 
Cc: Eric Dumazet 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

udp_diag: Fix socket skipping within chain

2015-02-27T01:48:48+00:00

[ Upstream commit 86f3cddbc3037882414c7308973530167906b7e9 ]

While working on rhashtable walking I noticed that the UDP diag
dumping code is buggy.  In particular, the socket skipping within
a chain never happens, even though we record the number of sockets
that should be skipped.

As this code was supposedly copied from TCP, this patch does what
TCP does and resets num before we walk a chain.

Signed-off-by: Herbert Xu 
Acked-by: Pavel Emelyanov 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman