linux-stable.git/net/ethernet, branch linux-4.9.y

net: add annotations on hh->hh_len lockless accesses

2020-01-12T10:24:19+00:00

[ Upstream commit c305c6ae79e2ce20c22660ceda94f0d86d639a82 ]

KCSAN reported a data-race [1]

While we can use READ_ONCE() on the read sides,
we need to make sure hh->hh_len is written last.

[1]

BUG: KCSAN: data-race in eth_header_cache / neigh_resolve_output

write to 0xffff8880b9dedcb8 of 4 bytes by task 29760 on cpu 0:
 eth_header_cache+0xa9/0xd0 net/ethernet/eth.c:247
 neigh_hh_init net/core/neighbour.c:1463 [inline]
 neigh_resolve_output net/core/neighbour.c:1480 [inline]
 neigh_resolve_output+0x415/0x470 net/core/neighbour.c:1470
 neigh_output include/net/neighbour.h:511 [inline]
 ip6_finish_output2+0x7a2/0xec0 net/ipv6/ip6_output.c:116
 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline]
 __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127
 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ndisc_send_skb+0x459/0x5f0 net/ipv6/ndisc.c:505
 ndisc_send_ns+0x207/0x430 net/ipv6/ndisc.c:647
 rt6_probe_deferred+0x98/0xf0 net/ipv6/route.c:615
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffff8880b9dedcb8 of 4 bytes by task 29572 on cpu 1:
 neigh_resolve_output net/core/neighbour.c:1479 [inline]
 neigh_resolve_output+0x113/0x470 net/core/neighbour.c:1470
 neigh_output include/net/neighbour.h:511 [inline]
 ip6_finish_output2+0x7a2/0xec0 net/ipv6/ip6_output.c:116
 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline]
 __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127
 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ndisc_send_skb+0x459/0x5f0 net/ipv6/ndisc.c:505
 ndisc_send_ns+0x207/0x430 net/ipv6/ndisc.c:647
 rt6_probe_deferred+0x98/0xf0 net/ipv6/route.c:615
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 29572 Comm: kworker/1:4 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events rt6_probe_deferred

Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: introduce device min_header_len

2017-02-18T14:11:43+00:00

[ Upstream commit 217e6fa24ce28ec87fca8da93c9016cb78028612 ]

The stack must not pass packets to device drivers that are shorter
than the minimum link layer header length.

Previously, packet sockets would drop packets smaller than or equal
to dev->hard_header_len, but this has false positives. Zero length
payload is used over Ethernet. Other link layer protocols support
variable length headers. Support for validation of these protocols
removed the min length check for all protocols.

Introduce an explicit dev->min_header_len parameter and drop all
packets below this value. Initially, set it to non-zero only for
Ethernet and loopback. Other protocols can follow in a patch to
net-next.

Fixes: 9ed988cd5915 ("packet: validate variable length ll headers")
Reported-by: Sowmini Varadhan 
Signed-off-by: Willem de Bruijn 
Acked-by: Eric Dumazet 
Acked-by: Sowmini Varadhan 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: add recursion limit to GRO

2016-10-20T18:32:22+00:00

Currently, GRO can do unlimited recursion through the gro_receive
handlers.  This was fixed for tunneling protocols by limiting tunnel GRO
to one level with encap_mark, but both VLAN and TEB still have this
problem.  Thus, the kernel is vulnerable to a stack overflow, if we
receive a packet composed entirely of VLAN headers.

This patch adds a recursion counter to the GRO layer to prevent stack
overflow.  When a gro_receive function hits the recursion limit, GRO is
aborted for this skb and it is processed normally.  This recursion
counter is put in the GRO CB, but could be turned into a percpu counter
if we run out of space in the CB.

Thanks to Vladimír Beneš  for the initial bug report.

Fixes: CVE-2016-7039
Fixes: 9b174d88c257 ("net: Add Transparent Ethernet Bridging GRO support.")
Fixes: 66e5133f19e9 ("vlan: Add GRO support for non hardware accelerated vlan")
Signed-off-by: Sabrina Dubroca 
Reviewed-by: Jiri Benc 
Acked-by: Hannes Frederic Sowa 
Acked-by: Tom Herbert 
Signed-off-by: David S. Miller

eth: Pull header from first fragment via eth_get_headlen

2016-02-24T18:58:05+00:00

We want to try and pull the L4 header in if it is available in the first
fragment.  As such add the flag to indicate we want to pull the headers on
the first fragment in.

Signed-off-by: Alexander Duyck 
Acked-by: Tom Herbert 
Signed-off-by: David S. Miller

net: Add eth_platform_get_mac_address() helper.

2016-01-06T21:31:56+00:00

A repeating pattern in drivers has become to use OF node information
and, if not found, platform specific host information to extract the
ethernet address for a given device.

Currently this is done with a call to of_get_mac_address() and then
some ifdef'd stuff for SPARC.

Consolidate this into a portable routine, and provide the
arch_get_platform_mac_address() weak function hook for all
architectures to implement if they want.

Signed-off-by: David S. Miller

net: help compiler generate better code in eth_get_headlen

2015-09-29T05:51:15+00:00

Noticed that the compiler (gcc version 4.8.5 20150623 (Red Hat 4.8.5-4) (GCC))
generated suboptimal assembler code in eth_get_headlen().

This early return coding style is usually not an issue, on super scalar CPUs,
but the compiler choose to put the return statement after this very unlikely
branch, thus creating larger jump down to the likely code path.

Performance wise, I could measure slightly less L1-icache-load-misses
and less branch-misses, and an improvement of 1 nanosec with an IP-forwarding
use-case with 257 bytes packets with ixgbe (CPU i7-4790K @ 4.00GHz).

Signed-off-by: Jesper Dangaard Brouer 
Signed-off-by: David S. Miller

flow_dissector: Add flags argument to skb_flow_dissector functions

2015-09-01T22:06:22+00:00

The flags argument will allow control of the dissection process (for
instance whether to parse beyond L3).

Signed-off-by: Tom Herbert 
Signed-off-by: David S. Miller

net: ethernet: Fix double word "the the" in eth.c

2015-08-10T05:53:00+00:00

This patch fix double word "the the" in
Documentation/DocBook/networking/API-eth-get-headlen.html
Documentation/DocBook/networking/netdev.html
Documentation/DocBook/networking.xml

These files are generated from comment in source,
so I have to fix comment in net/ethernet/eth.c.

Signed-off-by: Masanari Iida 
Signed-off-by: David S. Miller

net: Add full IPv6 addresses to flow_keys

2015-06-04T22:44:30+00:00

This patch adds full IPv6 addresses into flow_keys and uses them as
input to the flow hash function. The implementation supports either
IPv4 or IPv6 addresses in a union, and selector is used to determine
how may words to input to jhash2.

We also add flow_get_u32_dst and flow_get_u32_src functions which are
used to get a u32 representation of the source and destination
addresses. For IPv6, ipv6_addr_hash is called. These functions retain
getting the legacy values of src and dst in flow_keys.

With this patch, Ethertype and IP protocol are now included in the
flow hash input.

Signed-off-by: Tom Herbert 
Signed-off-by: David S. Miller

net: Add priority to packet_offload objects.

2015-06-01T21:56:09+00:00

When we scan a packet for GRO processing, we want to see the most
common packet types in the front of the offload_base list.

So add a priority field so we can handle this properly.

IPv4/IPv6 get the highest priority with the implicit zero priority
field.

Next comes ethernet with a priority of 10, and then we have the MPLS
types with a priority of 15.

Suggested-by: Eric Dumazet 
Suggested-by: Toshiaki Makita 
Signed-off-by: David S. Miller