linux-stable.git/include/net, branch v3.16.40

tcp: take care of truncations done by sk_filter()

2017-02-23T03:54:46+00:00

commit ac6e780070e30e4c35bd395acfe9191e6268bdd3 upstream.

With syzkaller help, Marco Grassi found a bug in TCP stack,
crashing in tcp_collapse()

Root cause is that sk_filter() can truncate the incoming skb,
but TCP stack was not really expecting this to happen.
It probably was expecting a simple DROP or ACCEPT behavior.

We first need to make sure no part of TCP header could be removed.
Then we need to adjust TCP_SKB_CB(skb)->end_seq

Many thanks to syzkaller team and Marco for giving us a reproducer.

Signed-off-by: Eric Dumazet 
Reported-by: Marco Grassi 
Reported-by: Vladis Dronov 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

dccp: limit sk_filter trim to payload

2017-02-23T03:54:46+00:00

commit 4f0c40d94461cfd23893a17335b2ab78ecb333c8 upstream.

Dccp verifies packet integrity, including length, at initial rcv in
dccp_invalid_packet, later pulls headers in dccp_enqueue_skb.

A call to sk_filter in-between can cause __skb_pull to wrap skb->len.
skb_copy_datagram_msg interprets this as a negative value, so
(correctly) fails with EFAULT. The negative length is reported in
ioctl SIOCINQ or possibly in a DCCP_WARN in dccp_close.

Introduce an sk_receive_skb variant that caps how small a filter
program can trim packets, and call this in dccp with the header
length. Excessively trimmed packets are now processed normally and
queued for reception as 0B payloads.

Fixes: 7c657876b63c ("[DCCP]: Initial implementation")
Signed-off-by: Willem de Bruijn 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: Add __sock_queue_rcv_skb()

2017-02-23T03:54:46+00:00

Extraxcted from commit e6afc8ace6dd5cef5e812f26c72579da8806f5ac
"udp: remove headers from UDP packets before queueing".

Signed-off-by: Ben Hutchings

ip6_tunnel: Clear IP6CB in ip6tunnel_xmit()

2017-02-23T03:54:27+00:00

commit 23f4ffedb7d751c7e298732ba91ca75d224bc1a6 upstream.

skb->cb may contain data from previous layers. In the observed scenario,
the garbage data were misinterpreted as IP6CB(skb)->frag_max_size, so
that small packets sent through the tunnel are mistakenly fragmented.

This patch unconditionally clears the control buffer in ip6tunnel_xmit(),
which affects ip6_tunnel, ip6_udp_tunnel and ip6_gre. Currently none of
these tunnels set IP6CB(skb)->flags, otherwise it needs to be done earlier.

Signed-off-by: Eli Cooper 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

netfilter: nf_tables: fix type mismatch with error return from nft_parse_u32_check

2017-02-23T03:54:23+00:00

commit f1d505bb762e30bf316ff5d3b604914649d6aed3 upstream.

Commit 36b701fae12ac ("netfilter: nf_tables: validate maximum value of
u32 netlink attributes") introduced nft_parse_u32_check with a return
value of "unsigned int", yet on error it returns "-ERANGE".

This patch corrects the mismatch by changing the return value to "int",
which happens to match the actual users of nft_parse_u32_check already.

Found by Coverity, CID 1373930.

Note that commit 21a9e0f1568ea ("netfilter: nft_exthdr: fix error
handling in nft_exthdr_init()) attempted to address the issue, but
did not address the return type of nft_parse_u32_check.

Signed-off-by: John W. Linville 
Cc: Laura Garcia Liebana 
Cc: Pablo Neira Ayuso 
Cc: Dan Carpenter 
Fixes: 36b701fae12ac ("netfilter: nf_tables: validate maximum value...")
Signed-off-by: Pablo Neira Ayuso 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

netfilter: nf_tables: validate maximum value of u32 netlink attributes

2017-02-23T03:54:03+00:00

commit 36b701fae12ac763a568037e4e7c96b5727a8b3e upstream.

Fetch value and validate u32 netlink attribute. This validation is
usually required when the u32 netlink attributes are being stored in a
field whose size is smaller.

This patch revisits 4da449ae1df9 ("netfilter: nft_exthdr: Add size check
on u8 nft_exthdr attributes").

Fixes: 96518518cc41 ("netfilter: add nftables")
Suggested-by: Pablo Neira Ayuso 
Signed-off-by: Laura Garcia Liebana 
Signed-off-by: Pablo Neira Ayuso 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

tcp: fix use after free in tcp_xmit_retransmit_queue()

2016-11-20T01:17:13+00:00

commit bb1fceca22492109be12640d49f5ea5a544c6bb4 upstream.

When tcp_sendmsg() allocates a fresh and empty skb, it puts it at the
tail of the write queue using tcp_add_write_queue_tail()

Then it attempts to copy user data into this fresh skb.

If the copy fails, we undo the work and remove the fresh skb.

Unfortunately, this undo lacks the change done to tp->highest_sack and
we can leave a dangling pointer (to a freed skb)

Later, tcp_xmit_retransmit_queue() can dereference this pointer and
access freed memory. For regular kernels where memory is not unmapped,
this might cause SACK bugs because tcp_highest_sack_seq() is buggy,
returning garbage instead of tp->snd_nxt, but with various debug
features like CONFIG_DEBUG_PAGEALLOC, this can crash the kernel.

This bug was found by Marco Grassi thanks to syzkaller.

Fixes: 6859d49475d4 ("[TCP]: Abstract tp->highest_sack accessing & point to next skb")
Reported-by: Marco Grassi 
Signed-off-by: Eric Dumazet 
Cc: Ilpo Järvinen 
Cc: Yuchung Cheng 
Cc: Neal Cardwell 
Acked-by: Neal Cardwell 
Reviewed-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

ipv6: suppress sparse warnings in IP6_ECN_set_ce()

2016-11-20T01:17:10+00:00

commit c15c0ab12fd62f2b19181d05c62d24bc9fa55a42 upstream.

Pass the correct type __wsum to csum_sub() and csum_add(). This doesn't
really change anything since __wsum really *is* __be32, but removes the
address space warnings from sparse.

Cc: Eric Dumazet 
Fixes: 34ae6a1aa054 ("ipv6: update skb->csum when CE mark is propagated")
Signed-off-by: Johannes Berg 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net_sched: update hierarchical backlog too

2016-08-22T21:38:15+00:00

commit 2ccccf5fb43ff62b2b96cc58d95fc0b3596516e4 upstream.

When the bottom qdisc decides to, for example, drop some packet,
it calls qdisc_tree_decrease_qlen() to update the queue length
for all its ancestors, we need to update the backlog too to
keep the stats on root qdisc accurate.

Cc: Jamal Hadi Salim 
Acked-by: Jamal Hadi Salim 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

net_sched: introduce qdisc_replace() helper

2016-08-22T21:38:15+00:00

commit 86a7996cc8a078793670d82ed97d5a99bb4e8496 upstream.

Remove nearly duplicated code and prepare for the following patch.

Cc: Jamal Hadi Salim 
Acked-by: Jamal Hadi Salim 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings