linux-stable.git/net/core/dev.c, branch v4.9.7 Linux kernel stable tree gro: use min_t() in skb_gro_reset_offset() 2017-01-15T12:42:55+00:00 Eric Dumazet edumazet@google.com 2017-01-11T03:52:43+00:00 934ca017c85083ee25062f4d92935f6edc336bd5 [ Upstream commit 7cfd5fd5a9813f1430290d20c0fead9b4582a307 ] On 32bit arches, (skb->end - skb->data) is not 'unsigned int', so we shall use min_t() instead of min() to avoid a compiler error. Fixes: 1272ce87fa01 ("gro: Enter slow-path if there is no tailroom") Reported-by: kernel test robot <fengguang.wu@intel.com> 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 7cfd5fd5a9813f1430290d20c0fead9b4582a307 ]

On 32bit arches, (skb->end - skb->data) is not 'unsigned int',
so we shall use min_t() instead of min() to avoid a compiler error.

Fixes: 1272ce87fa01 ("gro: Enter slow-path if there is no tailroom")
Reported-by: kernel test robot <fengguang.wu@intel.com>
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>
gro: Enter slow-path if there is no tailroom 2017-01-15T12:42:55+00:00 Herbert Xu herbert@gondor.apana.org.au 2017-01-10T20:24:01+00:00 ec0fdcb88c6f451dc3d436406de69fbf48a2e1da [ Upstream commit 1272ce87fa017ca4cf32920764d879656b7a005a ] The GRO path has a fast-path where we avoid calling pskb_may_pull and pskb_expand by directly accessing frag0. However, this should only be done if we have enough tailroom in the skb as otherwise we'll have to expand it later anyway. This patch adds the check by capping frag0_len with the skb tailroom. Fixes: cb18978cbf45 ("gro: Open-code final pskb_may_pull") Reported-by: Slava Shwartsman <slavash@mellanox.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 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 1272ce87fa017ca4cf32920764d879656b7a005a ]

The GRO path has a fast-path where we avoid calling pskb_may_pull
and pskb_expand by directly accessing frag0.  However, this should
only be done if we have enough tailroom in the skb as otherwise
we'll have to expand it later anyway.

This patch adds the check by capping frag0_len with the skb tailroom.

Fixes: cb18978cbf45 ("gro: Open-code final pskb_may_pull")
Reported-by: Slava Shwartsman <slavash@mellanox.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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>
bpf: Fix bpf_redirect to an ipip/ip6tnl dev 2016-11-13T04:38:07+00:00 Martin KaFai Lau kafai@fb.com 2016-11-09T23:36:33+00:00 4e3264d21b90984c2165e8fe5a7b64cf25bc2c2d If the bpf program calls bpf_redirect(dev, 0) and dev is an ipip/ip6tnl, it currently includes the mac header. e.g. If dev is ipip, the end result is IP-EthHdr-IP instead of IP-IP. The fix is to pull the mac header. At ingress, skb_postpull_rcsum() is not needed because the ethhdr should have been pulled once already and then got pushed back just before calling the bpf_prog. At egress, this patch calls skb_postpull_rcsum(). If bpf_redirect(dev, BPF_F_INGRESS) is called, it also fails now because it calls dev_forward_skb() which eventually calls eth_type_trans(skb, dev). The eth_type_trans() will set skb->type = PACKET_OTHERHOST because the mac address does not match the redirecting dev->dev_addr. The PACKET_OTHERHOST will eventually cause the ip_rcv() errors out. To fix this, ____dev_forward_skb() is added. Joint work with Daniel Borkmann. Fixes: cfc7381b3002 ("ip_tunnel: add collect_md mode to IPIP tunnel") Fixes: 8d79266bc48c ("ip6_tunnel: add collect_md mode to IPv6 tunnels") Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@fb.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
If the bpf program calls bpf_redirect(dev, 0) and dev is
an ipip/ip6tnl, it currently includes the mac header.
e.g. If dev is ipip, the end result is IP-EthHdr-IP instead
of IP-IP.

The fix is to pull the mac header.  At ingress, skb_postpull_rcsum()
is not needed because the ethhdr should have been pulled once already
and then got pushed back just before calling the bpf_prog.
At egress, this patch calls skb_postpull_rcsum().

If bpf_redirect(dev, BPF_F_INGRESS) is called,
it also fails now because it calls dev_forward_skb() which
eventually calls eth_type_trans(skb, dev).  The eth_type_trans()
will set skb->type = PACKET_OTHERHOST because the mac address
does not match the redirecting dev->dev_addr.  The PACKET_OTHERHOST
will eventually cause the ip_rcv() errors out.  To fix this,
____dev_forward_skb() is added.

Joint work with Daniel Borkmann.

Fixes: cfc7381b3002 ("ip_tunnel: add collect_md mode to IPIP tunnel")
Fixes: 8d79266bc48c ("ip6_tunnel: add collect_md mode to IPv6 tunnels")
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: mangle zero checksum in skb_checksum_help() 2016-10-31T19:29:11+00:00 Eric Dumazet edumazet@google.com 2016-10-29T18:02:36+00:00 4f2e4ad56a65f3b7d64c258e373cb71e8d2499f4 Sending zero checksum is ok for TCP, but not for UDP. UDPv6 receiver should by default drop a frame with a 0 checksum, and UDPv4 would not verify the checksum and might accept a corrupted packet. Simply replace such checksum by 0xffff, regardless of transport. This error was caught on SIT tunnels, but seems generic. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Maciej Żenczykowski <maze@google.com> Cc: Willem de Bruijn <willemb@google.com> Acked-by: Maciej Żenczykowski <maze@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Sending zero checksum is ok for TCP, but not for UDP.

UDPv6 receiver should by default drop a frame with a 0 checksum,
and UDPv4 would not verify the checksum and might accept a corrupted
packet.

Simply replace such checksum by 0xffff, regardless of transport.

This error was caught on SIT tunnels, but seems generic.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Acked-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-10-30T03:33:20+00:00 Linus Torvalds torvalds@linux-foundation.org 2016-10-30T03:33:20+00:00 2a26d99b251b8625d27aed14e97fc10707a3a81f Pull networking fixes from David Miller: "Lots of fixes, mostly drivers as is usually the case. 1) Don't treat zero DMA address as invalid in vmxnet3, from Alexey Khoroshilov. 2) Fix element timeouts in netfilter's nft_dynset, from Anders K. Pedersen. 3) Don't put aead_req crypto struct on the stack in mac80211, from Ard Biesheuvel. 4) Several uninitialized variable warning fixes from Arnd Bergmann. 5) Fix memory leak in cxgb4, from Colin Ian King. 6) Fix bpf handling of VLAN header push/pop, from Daniel Borkmann. 7) Several VRF semantic fixes from David Ahern. 8) Set skb->protocol properly in ip6_tnl_xmit(), from Eli Cooper. 9) Socket needs to be locked in udp_disconnect(), from Eric Dumazet. 10) Div-by-zero on 32-bit fix in mlx4 driver, from Eugenia Emantayev. 11) Fix stale link state during failover in NCSCI driver, from Gavin Shan. 12) Fix netdev lower adjacency list traversal, from Ido Schimmel. 13) Propvide proper handle when emitting notifications of filter deletes, from Jamal Hadi Salim. 14) Memory leaks and big-endian issues in rtl8xxxu, from Jes Sorensen. 15) Fix DESYNC_FACTOR handling in ipv6, from Jiri Bohac. 16) Several routing offload fixes in mlxsw driver, from Jiri Pirko. 17) Fix broadcast sync problem in TIPC, from Jon Paul Maloy. 18) Validate chunk len before using it in SCTP, from Marcelo Ricardo Leitner. 19) Revert a netns locking change that causes regressions, from Paul Moore. 20) Add recursion limit to GRO handling, from Sabrina Dubroca. 21) GFP_KERNEL in irq context fix in ibmvnic, from Thomas Falcon. 22) Avoid accessing stale vxlan/geneve socket in data path, from Pravin Shelar" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (189 commits) geneve: avoid using stale geneve socket. vxlan: avoid using stale vxlan socket. qede: Fix out-of-bound fastpath memory access net: phy: dp83848: add dp83822 PHY support enic: fix rq disable tipc: fix broadcast link synchronization problem ibmvnic: Fix missing brackets in init_sub_crq_irqs ibmvnic: Fix releasing of sub-CRQ IRQs in interrupt context Revert "ibmvnic: Fix releasing of sub-CRQ IRQs in interrupt context" arch/powerpc: Update parameters for csum_tcpudp_magic & csum_tcpudp_nofold net/mlx4_en: Save slave ethtool stats command net/mlx4_en: Fix potential deadlock in port statistics flow net/mlx4: Fix firmware command timeout during interrupt test net/mlx4_core: Do not access comm channel if it has not yet been initialized net/mlx4_en: Fix panic during reboot net/mlx4_en: Process all completions in RX rings after port goes up net/mlx4_en: Resolve dividing by zero in 32-bit system net/mlx4_core: Change the default value of enable_qos net/mlx4_core: Avoid setting ports to auto when only one port type is supported net/mlx4_core: Fix the resource-type enum in res tracker to conform to FW spec ... 
Pull networking fixes from David Miller:
 "Lots of fixes, mostly drivers as is usually the case.

   1) Don't treat zero DMA address as invalid in vmxnet3, from Alexey
      Khoroshilov.

   2) Fix element timeouts in netfilter's nft_dynset, from Anders K.
      Pedersen.

   3) Don't put aead_req crypto struct on the stack in mac80211, from
      Ard Biesheuvel.

   4) Several uninitialized variable warning fixes from Arnd Bergmann.

   5) Fix memory leak in cxgb4, from Colin Ian King.

   6) Fix bpf handling of VLAN header push/pop, from Daniel Borkmann.

   7) Several VRF semantic fixes from David Ahern.

   8) Set skb->protocol properly in ip6_tnl_xmit(), from Eli Cooper.

   9) Socket needs to be locked in udp_disconnect(), from Eric Dumazet.

  10) Div-by-zero on 32-bit fix in mlx4 driver, from Eugenia Emantayev.

  11) Fix stale link state during failover in NCSCI driver, from Gavin
      Shan.

  12) Fix netdev lower adjacency list traversal, from Ido Schimmel.

  13) Propvide proper handle when emitting notifications of filter
      deletes, from Jamal Hadi Salim.

  14) Memory leaks and big-endian issues in rtl8xxxu, from Jes Sorensen.

  15) Fix DESYNC_FACTOR handling in ipv6, from Jiri Bohac.

  16) Several routing offload fixes in mlxsw driver, from Jiri Pirko.

  17) Fix broadcast sync problem in TIPC, from Jon Paul Maloy.

  18) Validate chunk len before using it in SCTP, from Marcelo Ricardo
      Leitner.

  19) Revert a netns locking change that causes regressions, from Paul
      Moore.

  20) Add recursion limit to GRO handling, from Sabrina Dubroca.

  21) GFP_KERNEL in irq context fix in ibmvnic, from Thomas Falcon.

  22) Avoid accessing stale vxlan/geneve socket in data path, from
      Pravin Shelar"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (189 commits)
  geneve: avoid using stale geneve socket.
  vxlan: avoid using stale vxlan socket.
  qede: Fix out-of-bound fastpath memory access
  net: phy: dp83848: add dp83822 PHY support
  enic: fix rq disable
  tipc: fix broadcast link synchronization problem
  ibmvnic: Fix missing brackets in init_sub_crq_irqs
  ibmvnic: Fix releasing of sub-CRQ IRQs in interrupt context
  Revert "ibmvnic: Fix releasing of sub-CRQ IRQs in interrupt context"
  arch/powerpc: Update parameters for csum_tcpudp_magic & csum_tcpudp_nofold
  net/mlx4_en: Save slave ethtool stats command
  net/mlx4_en: Fix potential deadlock in port statistics flow
  net/mlx4: Fix firmware command timeout during interrupt test
  net/mlx4_core: Do not access comm channel if it has not yet been initialized
  net/mlx4_en: Fix panic during reboot
  net/mlx4_en: Process all completions in RX rings after port goes up
  net/mlx4_en: Resolve dividing by zero in 32-bit system
  net/mlx4_core: Change the default value of enable_qos
  net/mlx4_core: Avoid setting ports to auto when only one port type is supported
  net/mlx4_core: Fix the resource-type enum in res tracker to conform to FW spec
  ...
packet: on direct_xmit, limit tso and csum to supported devices 2016-10-29T19:02:15+00:00 Willem de Bruijn willemb@google.com 2016-10-26T15:23:07+00:00 104ba78c98808ae837d1f63aae58c183db5505df When transmitting on a packet socket with PACKET_VNET_HDR and PACKET_QDISC_BYPASS, validate device support for features requested in vnet_hdr. Drop TSO packets sent to devices that do not support TSO or have the feature disabled. Note that the latter currently do process those packets correctly, regardless of not advertising the feature. Because of SKB_GSO_DODGY, it is not sufficient to test device features with netif_needs_gso. Full validate_xmit_skb is needed. Switch to software checksum for non-TSO packets that request checksum offload if that device feature is unsupported or disabled. Note that similar to the TSO case, device drivers may perform checksum offload correctly even when not advertising it. When switching to software checksum, packets hit skb_checksum_help, which has two BUG_ON checksum not in linear segment. Packet sockets always allocate at least up to csum_start + csum_off + 2 as linear. Tested by running github.com/wdebruij/kerneltools/psock_txring_vnet.c ethtool -K eth0 tso off tx on psock_txring_vnet -d $dst -s $src -i eth0 -l 2000 -n 1 -q -v psock_txring_vnet -d $dst -s $src -i eth0 -l 2000 -n 1 -q -v -N ethtool -K eth0 tx off psock_txring_vnet -d $dst -s $src -i eth0 -l 1000 -n 1 -q -v -G psock_txring_vnet -d $dst -s $src -i eth0 -l 1000 -n 1 -q -v -G -N v2: - add EXPORT_SYMBOL_GPL(validate_xmit_skb_list) Fixes: d346a3fae3ff ("packet: introduce PACKET_QDISC_BYPASS socket option") Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net> 
When transmitting on a packet socket with PACKET_VNET_HDR and
PACKET_QDISC_BYPASS, validate device support for features requested
in vnet_hdr.

Drop TSO packets sent to devices that do not support TSO or have the
feature disabled. Note that the latter currently do process those
packets correctly, regardless of not advertising the feature.

Because of SKB_GSO_DODGY, it is not sufficient to test device features
with netif_needs_gso. Full validate_xmit_skb is needed.

Switch to software checksum for non-TSO packets that request checksum
offload if that device feature is unsupported or disabled. Note that
similar to the TSO case, device drivers may perform checksum offload
correctly even when not advertising it.

When switching to software checksum, packets hit skb_checksum_help,
which has two BUG_ON checksum not in linear segment. Packet sockets
always allocate at least up to csum_start + csum_off + 2 as linear.

Tested by running github.com/wdebruij/kerneltools/psock_txring_vnet.c

  ethtool -K eth0 tso off tx on
  psock_txring_vnet -d $dst -s $src -i eth0 -l 2000 -n 1 -q -v
  psock_txring_vnet -d $dst -s $src -i eth0 -l 2000 -n 1 -q -v -N

  ethtool -K eth0 tx off
  psock_txring_vnet -d $dst -s $src -i eth0 -l 1000 -n 1 -q -v -G
  psock_txring_vnet -d $dst -s $src -i eth0 -l 1000 -n 1 -q -v -G -N

v2:
  - add EXPORT_SYMBOL_GPL(validate_xmit_skb_list)

Fixes: d346a3fae3ff ("packet: introduce PACKET_QDISC_BYPASS socket option")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: add recursion limit to GRO 2016-10-20T18:32:22+00:00 Sabrina Dubroca sd@queasysnail.net 2016-10-20T13:58:02+00:00 fcd91dd449867c6bfe56a81cabba76b829fd05cd 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 <vbenes@redhat.com> 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 <sd@queasysnail.net> Reviewed-by: Jiri Benc <jbenc@redhat.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
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 <vbenes@redhat.com> 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 <sd@queasysnail.net>
Reviewed-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: core: Correctly iterate over lower adjacency list 2016-10-19T14:38:08+00:00 Ido Schimmel idosch@mellanox.com 2016-10-19T13:57:08+00:00 e4961b0768852d9eb7383e1a5df178eacb714656 Tamir reported the following trace when processing ARP requests received via a vlan device on top of a VLAN-aware bridge: NMI watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [swapper/1:0] [...] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 4.8.0-rc7 #1 Hardware name: Mellanox Technologies Ltd. "MSN2100-CB2F"/"SA001017", BIOS 5.6.5 06/07/2016 task: ffff88017edfea40 task.stack: ffff88017ee10000 RIP: 0010:[<ffffffff815dcc73>] [<ffffffff815dcc73>] netdev_all_lower_get_next_rcu+0x33/0x60 [...] Call Trace: <IRQ> [<ffffffffa015de0a>] mlxsw_sp_port_lower_dev_hold+0x5a/0xa0 [mlxsw_spectrum] [<ffffffffa016f1b0>] mlxsw_sp_router_netevent_event+0x80/0x150 [mlxsw_spectrum] [<ffffffff810ad07a>] notifier_call_chain+0x4a/0x70 [<ffffffff810ad13a>] atomic_notifier_call_chain+0x1a/0x20 [<ffffffff815ee77b>] call_netevent_notifiers+0x1b/0x20 [<ffffffff815f2eb6>] neigh_update+0x306/0x740 [<ffffffff815f38ce>] neigh_event_ns+0x4e/0xb0 [<ffffffff8165ea3f>] arp_process+0x66f/0x700 [<ffffffff8170214c>] ? common_interrupt+0x8c/0x8c [<ffffffff8165ec29>] arp_rcv+0x139/0x1d0 [<ffffffff816e505a>] ? vlan_do_receive+0xda/0x320 [<ffffffff815e3794>] __netif_receive_skb_core+0x524/0xab0 [<ffffffff815e6830>] ? dev_queue_xmit+0x10/0x20 [<ffffffffa06d612d>] ? br_forward_finish+0x3d/0xc0 [bridge] [<ffffffffa06e5796>] ? br_handle_vlan+0xf6/0x1b0 [bridge] [<ffffffff815e3d38>] __netif_receive_skb+0x18/0x60 [<ffffffff815e3dc0>] netif_receive_skb_internal+0x40/0xb0 [<ffffffff815e3e4c>] netif_receive_skb+0x1c/0x70 [<ffffffffa06d7856>] br_pass_frame_up+0xc6/0x160 [bridge] [<ffffffffa06d63d7>] ? deliver_clone+0x37/0x50 [bridge] [<ffffffffa06d656c>] ? br_flood+0xcc/0x160 [bridge] [<ffffffffa06d7b14>] br_handle_frame_finish+0x224/0x4f0 [bridge] [<ffffffffa06d7f94>] br_handle_frame+0x174/0x300 [bridge] [<ffffffff815e3599>] __netif_receive_skb_core+0x329/0xab0 [<ffffffff81374815>] ? find_next_bit+0x15/0x20 [<ffffffff8135e802>] ? cpumask_next_and+0x32/0x50 [<ffffffff810c9968>] ? load_balance+0x178/0x9b0 [<ffffffff815e3d38>] __netif_receive_skb+0x18/0x60 [<ffffffff815e3dc0>] netif_receive_skb_internal+0x40/0xb0 [<ffffffff815e3e4c>] netif_receive_skb+0x1c/0x70 [<ffffffffa01544a1>] mlxsw_sp_rx_listener_func+0x61/0xb0 [mlxsw_spectrum] [<ffffffffa005c9f7>] mlxsw_core_skb_receive+0x187/0x200 [mlxsw_core] [<ffffffffa007332a>] mlxsw_pci_cq_tasklet+0x63a/0x9b0 [mlxsw_pci] [<ffffffff81091986>] tasklet_action+0xf6/0x110 [<ffffffff81704556>] __do_softirq+0xf6/0x280 [<ffffffff8109213f>] irq_exit+0xdf/0xf0 [<ffffffff817042b4>] do_IRQ+0x54/0xd0 [<ffffffff8170214c>] common_interrupt+0x8c/0x8c The problem is that netdev_all_lower_get_next_rcu() never advances the iterator, thereby causing the loop over the lower adjacency list to run forever. Fix this by advancing the iterator and avoid the infinite loop. Fixes: 7ce856aaaf13 ("mlxsw: spectrum: Add couple of lower device helper functions") Signed-off-by: Ido Schimmel <idosch@mellanox.com> Reported-by: Tamir Winetroub <tamirw@mellanox.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Acked-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Tamir reported the following trace when processing ARP requests received
via a vlan device on top of a VLAN-aware bridge:

 NMI watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [swapper/1:0]
[...]
 CPU: 1 PID: 0 Comm: swapper/1 Tainted: G        W       4.8.0-rc7 #1
 Hardware name: Mellanox Technologies Ltd. "MSN2100-CB2F"/"SA001017", BIOS 5.6.5 06/07/2016
 task: ffff88017edfea40 task.stack: ffff88017ee10000
 RIP: 0010:[<ffffffff815dcc73>]  [<ffffffff815dcc73>] netdev_all_lower_get_next_rcu+0x33/0x60
[...]
 Call Trace:
  <IRQ>
  [<ffffffffa015de0a>] mlxsw_sp_port_lower_dev_hold+0x5a/0xa0 [mlxsw_spectrum]
  [<ffffffffa016f1b0>] mlxsw_sp_router_netevent_event+0x80/0x150 [mlxsw_spectrum]
  [<ffffffff810ad07a>] notifier_call_chain+0x4a/0x70
  [<ffffffff810ad13a>] atomic_notifier_call_chain+0x1a/0x20
  [<ffffffff815ee77b>] call_netevent_notifiers+0x1b/0x20
  [<ffffffff815f2eb6>] neigh_update+0x306/0x740
  [<ffffffff815f38ce>] neigh_event_ns+0x4e/0xb0
  [<ffffffff8165ea3f>] arp_process+0x66f/0x700
  [<ffffffff8170214c>] ? common_interrupt+0x8c/0x8c
  [<ffffffff8165ec29>] arp_rcv+0x139/0x1d0
  [<ffffffff816e505a>] ? vlan_do_receive+0xda/0x320
  [<ffffffff815e3794>] __netif_receive_skb_core+0x524/0xab0
  [<ffffffff815e6830>] ? dev_queue_xmit+0x10/0x20
  [<ffffffffa06d612d>] ? br_forward_finish+0x3d/0xc0 [bridge]
  [<ffffffffa06e5796>] ? br_handle_vlan+0xf6/0x1b0 [bridge]
  [<ffffffff815e3d38>] __netif_receive_skb+0x18/0x60
  [<ffffffff815e3dc0>] netif_receive_skb_internal+0x40/0xb0
  [<ffffffff815e3e4c>] netif_receive_skb+0x1c/0x70
  [<ffffffffa06d7856>] br_pass_frame_up+0xc6/0x160 [bridge]
  [<ffffffffa06d63d7>] ? deliver_clone+0x37/0x50 [bridge]
  [<ffffffffa06d656c>] ? br_flood+0xcc/0x160 [bridge]
  [<ffffffffa06d7b14>] br_handle_frame_finish+0x224/0x4f0 [bridge]
  [<ffffffffa06d7f94>] br_handle_frame+0x174/0x300 [bridge]
  [<ffffffff815e3599>] __netif_receive_skb_core+0x329/0xab0
  [<ffffffff81374815>] ? find_next_bit+0x15/0x20
  [<ffffffff8135e802>] ? cpumask_next_and+0x32/0x50
  [<ffffffff810c9968>] ? load_balance+0x178/0x9b0
  [<ffffffff815e3d38>] __netif_receive_skb+0x18/0x60
  [<ffffffff815e3dc0>] netif_receive_skb_internal+0x40/0xb0
  [<ffffffff815e3e4c>] netif_receive_skb+0x1c/0x70
  [<ffffffffa01544a1>] mlxsw_sp_rx_listener_func+0x61/0xb0 [mlxsw_spectrum]
  [<ffffffffa005c9f7>] mlxsw_core_skb_receive+0x187/0x200 [mlxsw_core]
  [<ffffffffa007332a>] mlxsw_pci_cq_tasklet+0x63a/0x9b0 [mlxsw_pci]
  [<ffffffff81091986>] tasklet_action+0xf6/0x110
  [<ffffffff81704556>] __do_softirq+0xf6/0x280
  [<ffffffff8109213f>] irq_exit+0xdf/0xf0
  [<ffffffff817042b4>] do_IRQ+0x54/0xd0
  [<ffffffff8170214c>] common_interrupt+0x8c/0x8c

The problem is that netdev_all_lower_get_next_rcu() never advances the
iterator, thereby causing the loop over the lower adjacency list to run
forever.

Fix this by advancing the iterator and avoid the infinite loop.

Fixes: 7ce856aaaf13 ("mlxsw: spectrum: Add couple of lower device helper functions")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Tamir Winetroub <tamirw@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux 2016-10-15T17:03:15+00:00 Linus Torvalds torvalds@linux-foundation.org 2016-10-15T17:03:15+00:00 9ffc66941df278c9f4df979b6bcf6c6ddafedd16 Pull gcc plugins update from Kees Cook: "This adds a new gcc plugin named "latent_entropy". It is designed to extract as much possible uncertainty from a running system at boot time as possible, hoping to capitalize on any possible variation in CPU operation (due to runtime data differences, hardware differences, SMP ordering, thermal timing variation, cache behavior, etc). At the very least, this plugin is a much more comprehensive example for how to manipulate kernel code using the gcc plugin internals" * tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: latent_entropy: Mark functions with __latent_entropy gcc-plugins: Add latent_entropy plugin 
Pull gcc plugins update from Kees Cook:
 "This adds a new gcc plugin named "latent_entropy". It is designed to
  extract as much possible uncertainty from a running system at boot
  time as possible, hoping to capitalize on any possible variation in
  CPU operation (due to runtime data differences, hardware differences,
  SMP ordering, thermal timing variation, cache behavior, etc).

  At the very least, this plugin is a much more comprehensive example
  for how to manipulate kernel code using the gcc plugin internals"

* tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  latent_entropy: Mark functions with __latent_entropy
  gcc-plugins: Add latent_entropy plugin
latent_entropy: Mark functions with __latent_entropy 2016-10-10T21:51:45+00:00 Emese Revfy re.emese@gmail.com 2016-06-20T18:42:34+00:00 0766f788eb727e2e330d55d30545db65bcf2623f The __latent_entropy gcc attribute can be used only on functions and variables. If it is on a function then the plugin will instrument it for gathering control-flow entropy. If the attribute is on a variable then the plugin will initialize it with random contents. The variable must be an integer, an integer array type or a structure with integer fields. These specific functions have been selected because they are init functions (to help gather boot-time entropy), are called at unpredictable times, or they have variable loops, each of which provide some level of latent entropy. Signed-off-by: Emese Revfy <re.emese@gmail.com> [kees: expanded commit message] Signed-off-by: Kees Cook <keescook@chromium.org> 
The __latent_entropy gcc attribute can be used only on functions and
variables.  If it is on a function then the plugin will instrument it for
gathering control-flow entropy. If the attribute is on a variable then
the plugin will initialize it with random contents.  The variable must
be an integer, an integer array type or a structure with integer fields.

These specific functions have been selected because they are init
functions (to help gather boot-time entropy), are called at unpredictable
times, or they have variable loops, each of which provide some level of
latent entropy.

Signed-off-by: Emese Revfy <re.emese@gmail.com>
[kees: expanded commit message]
Signed-off-by: Kees Cook <keescook@chromium.org>