linux-toradex.git/net/ipv4, branch v4.4.23 Linux kernel for Apalis and Colibri modules vti: flush x-netns xfrm cache when vti interface is removed 2016-09-30T08:18:36+00:00 Lance Richardson lrichard@redhat.com 2016-08-09T19:29:42+00:00 0bb225a04dc3b730844a9d2acb5b4f9307b6e1f9 [ Upstream commit a5d0dc810abf3d6b241777467ee1d6efb02575fc ] When executing the script included below, the netns delete operation hangs with the following message (repeated at 10 second intervals): kernel:unregister_netdevice: waiting for lo to become free. Usage count = 1 This occurs because a reference to the lo interface in the "secure" netns is still held by a dst entry in the xfrm bundle cache in the init netns. Address this problem by garbage collecting the tunnel netns flow cache when a cross-namespace vti interface receives a NETDEV_DOWN notification. A more detailed description of the problem scenario (referencing commands in the script below): (1) ip link add vti_test type vti local 1.1.1.1 remote 1.1.1.2 key 1 The vti_test interface is created in the init namespace. vti_tunnel_init() attaches a struct ip_tunnel to the vti interface's netdev_priv(dev), setting the tunnel net to &init_net. (2) ip link set vti_test netns secure The vti_test interface is moved to the "secure" netns. Note that the associated struct ip_tunnel still has tunnel->net set to &init_net. (3) ip netns exec secure ping -c 4 -i 0.02 -I 192.168.100.1 192.168.200.1 The first packet sent using the vti device causes xfrm_lookup() to be called as follows: dst = xfrm_lookup(tunnel->net, skb_dst(skb), fl, NULL, 0); Note that tunnel->net is the init namespace, while skb_dst(skb) references the vti_test interface in the "secure" namespace. The returned dst references an interface in the init namespace. Also note that the first parameter to xfrm_lookup() determines which flow cache is used to store the computed xfrm bundle, so after xfrm_lookup() returns there will be a cached bundle in the init namespace flow cache with a dst referencing a device in the "secure" namespace. (4) ip netns del secure Kernel begins to delete the "secure" namespace. At some point the vti_test interface is deleted, at which point dst_ifdown() changes the dst->dev in the cached xfrm bundle flow from vti_test to lo (still in the "secure" namespace however). Since nothing has happened to cause the init namespace's flow cache to be garbage collected, this dst remains attached to the flow cache, so the kernel loops waiting for the last reference to lo to go away. <Begin script> ip link add br1 type bridge ip link set dev br1 up ip addr add dev br1 1.1.1.1/8 ip netns add secure ip link add vti_test type vti local 1.1.1.1 remote 1.1.1.2 key 1 ip link set vti_test netns secure ip netns exec secure ip link set vti_test up ip netns exec secure ip link s lo up ip netns exec secure ip addr add dev lo 192.168.100.1/24 ip netns exec secure ip route add 192.168.200.0/24 dev vti_test ip xfrm policy flush ip xfrm state flush ip xfrm policy add dir out tmpl src 1.1.1.1 dst 1.1.1.2 \ proto esp mode tunnel mark 1 ip xfrm policy add dir in tmpl src 1.1.1.2 dst 1.1.1.1 \ proto esp mode tunnel mark 1 ip xfrm state add src 1.1.1.1 dst 1.1.1.2 proto esp spi 1 \ mode tunnel enc des3_ede 0x112233445566778811223344556677881122334455667788 ip xfrm state add src 1.1.1.2 dst 1.1.1.1 proto esp spi 1 \ mode tunnel enc des3_ede 0x112233445566778811223344556677881122334455667788 ip netns exec secure ping -c 4 -i 0.02 -I 192.168.100.1 192.168.200.1 ip netns del secure <End script> Reported-by: Hangbin Liu <haliu@redhat.com> Reported-by: Jan Tluka <jtluka@redhat.com> Signed-off-by: Lance Richardson <lrichard@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit a5d0dc810abf3d6b241777467ee1d6efb02575fc ]

When executing the script included below, the netns delete operation
hangs with the following message (repeated at 10 second intervals):

  kernel:unregister_netdevice: waiting for lo to become free. Usage count = 1

This occurs because a reference to the lo interface in the "secure" netns
is still held by a dst entry in the xfrm bundle cache in the init netns.

Address this problem by garbage collecting the tunnel netns flow cache
when a cross-namespace vti interface receives a NETDEV_DOWN notification.

A more detailed description of the problem scenario (referencing commands
in the script below):

(1) ip link add vti_test type vti local 1.1.1.1 remote 1.1.1.2 key 1

  The vti_test interface is created in the init namespace. vti_tunnel_init()
  attaches a struct ip_tunnel to the vti interface's netdev_priv(dev),
  setting the tunnel net to &init_net.

(2) ip link set vti_test netns secure

  The vti_test interface is moved to the "secure" netns. Note that
  the associated struct ip_tunnel still has tunnel->net set to &init_net.

(3) ip netns exec secure ping -c 4 -i 0.02 -I 192.168.100.1 192.168.200.1

  The first packet sent using the vti device causes xfrm_lookup() to be
  called as follows:

      dst = xfrm_lookup(tunnel->net, skb_dst(skb), fl, NULL, 0);

  Note that tunnel->net is the init namespace, while skb_dst(skb) references
  the vti_test interface in the "secure" namespace. The returned dst
  references an interface in the init namespace.

  Also note that the first parameter to xfrm_lookup() determines which flow
  cache is used to store the computed xfrm bundle, so after xfrm_lookup()
  returns there will be a cached bundle in the init namespace flow cache
  with a dst referencing a device in the "secure" namespace.

(4) ip netns del secure

  Kernel begins to delete the "secure" namespace.  At some point the
  vti_test interface is deleted, at which point dst_ifdown() changes
  the dst->dev in the cached xfrm bundle flow from vti_test to lo (still
  in the "secure" namespace however).
  Since nothing has happened to cause the init namespace's flow cache
  to be garbage collected, this dst remains attached to the flow cache,
  so the kernel loops waiting for the last reference to lo to go away.

<Begin script>
ip link add br1 type bridge
ip link set dev br1 up
ip addr add dev br1 1.1.1.1/8

ip netns add secure
ip link add vti_test type vti local 1.1.1.1 remote 1.1.1.2 key 1
ip link set vti_test netns secure
ip netns exec secure ip link set vti_test up
ip netns exec secure ip link s lo up
ip netns exec secure ip addr add dev lo 192.168.100.1/24
ip netns exec secure ip route add 192.168.200.0/24 dev vti_test
ip xfrm policy flush
ip xfrm state flush
ip xfrm policy add dir out tmpl src 1.1.1.1 dst 1.1.1.2 \
   proto esp mode tunnel mark 1
ip xfrm policy add dir in tmpl src 1.1.1.2 dst 1.1.1.1 \
   proto esp mode tunnel mark 1
ip xfrm state add src 1.1.1.1 dst 1.1.1.2 proto esp spi 1 \
   mode tunnel enc des3_ede 0x112233445566778811223344556677881122334455667788
ip xfrm state add src 1.1.1.2 dst 1.1.1.1 proto esp spi 1 \
   mode tunnel enc des3_ede 0x112233445566778811223344556677881122334455667788

ip netns exec secure ping -c 4 -i 0.02 -I 192.168.100.1 192.168.200.1

ip netns del secure
<End script>

Reported-by: Hangbin Liu <haliu@redhat.com>
Reported-by: Jan Tluka <jtluka@redhat.com>
Signed-off-by: Lance Richardson <lrichard@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tcp: properly scale window in tcp_v[46]_reqsk_send_ack() 2016-09-30T08:18:34+00:00 Eric Dumazet edumazet@google.com 2016-08-22T18:31:10+00:00 c867a11289ee74c4594a96ccccac16f4cc29519e [ Upstream commit 20a2b49fc538540819a0c552877086548cff8d8d ] When sending an ack in SYN_RECV state, we must scale the offered window if wscale option was negotiated and accepted. Tested: Following packetdrill test demonstrates the issue : 0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 +0 bind(3, ..., ...) = 0 +0 listen(3, 1) = 0 // Establish a connection. +0 < S 0:0(0) win 20000 <mss 1000,sackOK,wscale 7, nop, TS val 100 ecr 0> +0 > S. 0:0(0) ack 1 win 28960 <mss 1460,sackOK, TS val 100 ecr 100, nop, wscale 7> +0 < . 1:11(10) ack 1 win 156 <nop,nop,TS val 99 ecr 100> // check that window is properly scaled ! +0 > . 1:1(0) ack 1 win 226 <nop,nop,TS val 200 ecr 100> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> 
[ Upstream commit 20a2b49fc538540819a0c552877086548cff8d8d ]

When sending an ack in SYN_RECV state, we must scale the offered
window if wscale option was negotiated and accepted.

Tested:
 Following packetdrill test demonstrates the issue :

0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0

+0 bind(3, ..., ...) = 0
+0 listen(3, 1) = 0

// Establish a connection.
+0 < S 0:0(0) win 20000 <mss 1000,sackOK,wscale 7, nop, TS val 100 ecr 0>
+0 > S. 0:0(0) ack 1 win 28960 <mss 1460,sackOK, TS val 100 ecr 100, nop, wscale 7>

+0 < . 1:11(10) ack 1 win 156 <nop,nop,TS val 99 ecr 100>
// check that window is properly scaled !
+0 > . 1:1(0) ack 1 win 226 <nop,nop,TS val 200 ecr 100>

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
tcp: cwnd does not increase in TCP YeAH 2016-09-30T08:18:34+00:00 Artem Germanov agermanov@anchorfree.com 2016-09-07T17:49:36+00:00 98418550e124ec047918df8b3bb587e60bd39a8a [ Upstream commit db7196a0d0984b933ccf2cd6a60e26abf466e8a3 ] Commit 76174004a0f19785a328f40388e87e982bbf69b9 (tcp: do not slow start when cwnd equals ssthresh ) introduced regression in TCP YeAH. Using 100ms delay 1% loss virtual ethernet link kernel 4.2 shows bandwidth ~500KB/s for single TCP connection and kernel 4.3 and above (including 4.8-rc4) shows bandwidth ~100KB/s. That is caused by stalled cwnd when cwnd equals ssthresh. This patch fixes it by proper increasing cwnd in this case. Signed-off-by: Artem Germanov <agermanov@anchorfree.com> Acked-by: Dmitry Adamushko <d.adamushko@anchorfree.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Holger Hoffstätte <holger@applied-asynchrony.com> 
[ Upstream commit db7196a0d0984b933ccf2cd6a60e26abf466e8a3 ]

Commit 76174004a0f19785a328f40388e87e982bbf69b9
(tcp: do not slow start when cwnd equals ssthresh )
introduced regression in TCP YeAH. Using 100ms delay 1% loss virtual
ethernet link kernel 4.2 shows bandwidth ~500KB/s for single TCP
connection and kernel 4.3 and above (including 4.8-rc4) shows bandwidth
~100KB/s.
   That is caused by stalled cwnd when cwnd equals ssthresh. This patch
fixes it by proper increasing cwnd in this case.

Signed-off-by: Artem Germanov <agermanov@anchorfree.com>
Acked-by: Dmitry Adamushko <d.adamushko@anchorfree.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Holger Hoffstätte <holger@applied-asynchrony.com>
ipv4: panic in leaf_walk_rcu due to stale node pointer 2016-09-30T08:18:34+00:00 David Forster dforster@brocade.com 2016-08-03T14:13:01+00:00 6b8076b8a76bc7f3d51e51b9fb5b35853cc74138 [ Upstream commit 94d9f1c5906b20053efe375b6d66610bca4b8b64 ] Panic occurs when issuing "cat /proc/net/route" whilst populating FIB with > 1M routes. Use of cached node pointer in fib_route_get_idx is unsafe. BUG: unable to handle kernel paging request at ffffc90001630024 IP: [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0 PGD 11b08d067 PUD 11b08e067 PMD dac4b067 PTE 0 Oops: 0000 [#1] SMP Modules linked in: nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscac snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep virti acpi_cpufreq button parport_pc ppdev lp parport autofs4 ext4 crc16 mbcache jbd tio_ring virtio floppy uhci_hcd ehci_hcd usbcore usb_common libata scsi_mod CPU: 1 PID: 785 Comm: cat Not tainted 4.2.0-rc8+ #4 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 task: ffff8800da1c0bc0 ti: ffff88011a05c000 task.ti: ffff88011a05c000 RIP: 0010:[<ffffffff814cf6a0>] [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0 RSP: 0018:ffff88011a05fda0 EFLAGS: 00010202 RAX: ffff8800d8a40c00 RBX: ffff8800da4af940 RCX: ffff88011a05ff20 RDX: ffffc90001630020 RSI: 0000000001013531 RDI: ffff8800da4af950 RBP: 0000000000000000 R08: ffff8800da1f9a00 R09: 0000000000000000 R10: ffff8800db45b7e4 R11: 0000000000000246 R12: ffff8800da4af950 R13: ffff8800d97a74c0 R14: 0000000000000000 R15: ffff8800d97a7480 FS: 00007fd3970e0700(0000) GS:ffff88011fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: ffffc90001630024 CR3: 000000011a7e4000 CR4: 00000000000006e0 Stack: ffffffff814d00d3 0000000000000000 ffff88011a05ff20 ffff8800da1f9a00 ffffffff811dd8b9 0000000000000800 0000000000020000 00007fd396f35000 ffffffff811f8714 0000000000003431 ffffffff8138dce0 0000000000000f80 Call Trace: [<ffffffff814d00d3>] ? fib_route_seq_start+0x93/0xc0 [<ffffffff811dd8b9>] ? seq_read+0x149/0x380 [<ffffffff811f8714>] ? fsnotify+0x3b4/0x500 [<ffffffff8138dce0>] ? process_echoes+0x70/0x70 [<ffffffff8121cfa7>] ? proc_reg_read+0x47/0x70 [<ffffffff811bb823>] ? __vfs_read+0x23/0xd0 [<ffffffff811bbd42>] ? rw_verify_area+0x52/0xf0 [<ffffffff811bbe61>] ? vfs_read+0x81/0x120 [<ffffffff811bcbc2>] ? SyS_read+0x42/0xa0 [<ffffffff81549ab2>] ? entry_SYSCALL_64_fastpath+0x16/0x75 Code: 48 85 c0 75 d8 f3 c3 31 c0 c3 f3 c3 66 66 66 66 66 66 2e 0f 1f 84 00 00 a 04 89 f0 33 02 44 89 c9 48 d3 e8 0f b6 4a 05 49 89 RIP [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0 RSP <ffff88011a05fda0> CR2: ffffc90001630024 Signed-off-by: Dave Forster <dforster@brocade.com> Acked-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> 
[ Upstream commit 94d9f1c5906b20053efe375b6d66610bca4b8b64 ]

Panic occurs when issuing "cat /proc/net/route" whilst
populating FIB with > 1M routes.

Use of cached node pointer in fib_route_get_idx is unsafe.

 BUG: unable to handle kernel paging request at ffffc90001630024
 IP: [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0
 PGD 11b08d067 PUD 11b08e067 PMD dac4b067 PTE 0
 Oops: 0000 [#1] SMP
 Modules linked in: nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscac
 snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep virti
 acpi_cpufreq button parport_pc ppdev lp parport autofs4 ext4 crc16 mbcache jbd
tio_ring virtio floppy uhci_hcd ehci_hcd usbcore usb_common libata scsi_mod
 CPU: 1 PID: 785 Comm: cat Not tainted 4.2.0-rc8+ #4
 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
 task: ffff8800da1c0bc0 ti: ffff88011a05c000 task.ti: ffff88011a05c000
 RIP: 0010:[<ffffffff814cf6a0>]  [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0
 RSP: 0018:ffff88011a05fda0  EFLAGS: 00010202
 RAX: ffff8800d8a40c00 RBX: ffff8800da4af940 RCX: ffff88011a05ff20
 RDX: ffffc90001630020 RSI: 0000000001013531 RDI: ffff8800da4af950
 RBP: 0000000000000000 R08: ffff8800da1f9a00 R09: 0000000000000000
 R10: ffff8800db45b7e4 R11: 0000000000000246 R12: ffff8800da4af950
 R13: ffff8800d97a74c0 R14: 0000000000000000 R15: ffff8800d97a7480
 FS:  00007fd3970e0700(0000) GS:ffff88011fd00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: ffffc90001630024 CR3: 000000011a7e4000 CR4: 00000000000006e0
 Stack:
  ffffffff814d00d3 0000000000000000 ffff88011a05ff20 ffff8800da1f9a00
  ffffffff811dd8b9 0000000000000800 0000000000020000 00007fd396f35000
  ffffffff811f8714 0000000000003431 ffffffff8138dce0 0000000000000f80
 Call Trace:
  [<ffffffff814d00d3>] ? fib_route_seq_start+0x93/0xc0
  [<ffffffff811dd8b9>] ? seq_read+0x149/0x380
  [<ffffffff811f8714>] ? fsnotify+0x3b4/0x500
  [<ffffffff8138dce0>] ? process_echoes+0x70/0x70
  [<ffffffff8121cfa7>] ? proc_reg_read+0x47/0x70
  [<ffffffff811bb823>] ? __vfs_read+0x23/0xd0
  [<ffffffff811bbd42>] ? rw_verify_area+0x52/0xf0
  [<ffffffff811bbe61>] ? vfs_read+0x81/0x120
  [<ffffffff811bcbc2>] ? SyS_read+0x42/0xa0
  [<ffffffff81549ab2>] ? entry_SYSCALL_64_fastpath+0x16/0x75
 Code: 48 85 c0 75 d8 f3 c3 31 c0 c3 f3 c3 66 66 66 66 66 66 2e 0f 1f 84 00 00
a 04 89 f0 33 02 44 89 c9 48 d3 e8 0f b6 4a 05 49 89
 RIP  [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0
  RSP <ffff88011a05fda0>
 CR2: ffffc90001630024

Signed-off-by: Dave Forster <dforster@brocade.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
udp: properly support MSG_PEEK with truncated buffers 2016-09-15T06:27:49+00:00 Eric Dumazet edumazet@google.com 2016-08-30T04:34:58+00:00 dfe2042d96065f044a794f684e9f7976a4ca6e24 [ Upstream commit 197c949e7798fbf28cfadc69d9ca0c2abbf93191 ] Backport of this upstream commit into stable kernels : 89c22d8c3b27 ("net: Fix skb csum races when peeking") exposed a bug in udp stack vs MSG_PEEK support, when user provides a buffer smaller than skb payload. In this case, skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov); returns -EFAULT. This bug does not happen in upstream kernels since Al Viro did a great job to replace this into : skb_copy_and_csum_datagram_msg(skb, sizeof(struct udphdr), msg); This variant is safe vs short buffers. For the time being, instead reverting Herbert Xu patch and add back skb->ip_summed invalid changes, simply store the result of udp_lib_checksum_complete() so that we avoid computing the checksum a second time, and avoid the problematic skb_copy_and_csum_datagram_iovec() call. This patch can be applied on recent kernels as it avoids a double checksumming, then backported to stable kernels as a bug fix. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 197c949e7798fbf28cfadc69d9ca0c2abbf93191 ]

Backport of this upstream commit into stable kernels :
89c22d8c3b27 ("net: Fix skb csum races when peeking")
exposed a bug in udp stack vs MSG_PEEK support, when user provides
a buffer smaller than skb payload.

In this case,
skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr),
                                 msg->msg_iov);
returns -EFAULT.

This bug does not happen in upstream kernels since Al Viro did a great
job to replace this into :
skb_copy_and_csum_datagram_msg(skb, sizeof(struct udphdr), msg);
This variant is safe vs short buffers.

For the time being, instead reverting Herbert Xu patch and add back
skb->ip_summed invalid changes, simply store the result of
udp_lib_checksum_complete() so that we avoid computing the checksum a
second time, and avoid the problematic
skb_copy_and_csum_datagram_iovec() call.

This patch can be applied on recent kernels as it avoids a double
checksumming, then backported to stable kernels as a bug fix.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tcp: consider recv buf for the initial window scale 2016-08-16T07:30:48+00:00 Soheil Hassas Yeganeh soheil@google.com 2016-07-29T13:34:02+00:00 9c946c931b63068c4197d9d0b4d24635418bc67d [ Upstream commit f626300a3e776ccc9671b0dd94698fb3aa315966 ] tcp_select_initial_window() intends to advertise a window scaling for the maximum possible window size. To do so, it considers the maximum of net.ipv4.tcp_rmem[2] and net.core.rmem_max as the only possible upper-bounds. However, users with CAP_NET_ADMIN can use SO_RCVBUFFORCE to set the socket's receive buffer size to values larger than net.ipv4.tcp_rmem[2] and net.core.rmem_max. Thus, SO_RCVBUFFORCE is effectively ignored by tcp_select_initial_window(). To fix this, consider the maximum of net.ipv4.tcp_rmem[2], net.core.rmem_max and socket's initial buffer space. Fixes: b0573dea1fb3 ("[NET]: Introduce SO_{SND,RCV}BUFFORCE socket options") Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Suggested-by: Neal Cardwell <ncardwell@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit f626300a3e776ccc9671b0dd94698fb3aa315966 ]

tcp_select_initial_window() intends to advertise a window
scaling for the maximum possible window size. To do so,
it considers the maximum of net.ipv4.tcp_rmem[2] and
net.core.rmem_max as the only possible upper-bounds.
However, users with CAP_NET_ADMIN can use SO_RCVBUFFORCE
to set the socket's receive buffer size to values
larger than net.ipv4.tcp_rmem[2] and net.core.rmem_max.
Thus, SO_RCVBUFFORCE is effectively ignored by
tcp_select_initial_window().

To fix this, consider the maximum of net.ipv4.tcp_rmem[2],
net.core.rmem_max and socket's initial buffer space.

Fixes: b0573dea1fb3 ("[NET]: Introduce SO_{SND,RCV}BUFFORCE socket options")
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Suggested-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv4: reject RTNH_F_DEAD and RTNH_F_LINKDOWN from user space 2016-08-16T07:30:47+00:00 Julian Anastasov ja@ssi.bg 2016-07-10T18:11:55+00:00 a9c221859696f976ba47ba39178af1175e4558e0 [ Upstream commit 80610229ef7b26615dbb6cb6e873709a60bacc9f ] Vegard Nossum is reporting for a crash in fib_dump_info when nh_dev = NULL and fib_nhs == 1: Pid: 50, comm: netlink.exe Not tainted 4.7.0-rc5+ RIP: 0033:[<00000000602b3d18>] RSP: 0000000062623890 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000006261b800 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000024 RDI: 000000006245ba00 RBP: 00000000626238f0 R08: 000000000000029c R09: 0000000000000000 R10: 0000000062468038 R11: 000000006245ba00 R12: 000000006245ba00 R13: 00000000625f96c0 R14: 00000000601e16f0 R15: 0000000000000000 Kernel panic - not syncing: Kernel mode fault at addr 0x2e0, ip 0x602b3d18 CPU: 0 PID: 50 Comm: netlink.exe Not tainted 4.7.0-rc5+ #581 Stack: 626238f0 960226a02 00000400 000000fe 62623910 600afca7 62623970 62623a48 62468038 00000018 00000000 00000000 Call Trace: [<602b3e93>] rtmsg_fib+0xd3/0x190 [<602b6680>] fib_table_insert+0x260/0x500 [<602b0e5d>] inet_rtm_newroute+0x4d/0x60 [<60250def>] rtnetlink_rcv_msg+0x8f/0x270 [<60267079>] netlink_rcv_skb+0xc9/0xe0 [<60250d4b>] rtnetlink_rcv+0x3b/0x50 [<60265400>] netlink_unicast+0x1a0/0x2c0 [<60265e47>] netlink_sendmsg+0x3f7/0x470 [<6021dc9a>] sock_sendmsg+0x3a/0x90 [<6021e0d0>] ___sys_sendmsg+0x300/0x360 [<6021fa64>] __sys_sendmsg+0x54/0xa0 [<6021fac0>] SyS_sendmsg+0x10/0x20 [<6001ea68>] handle_syscall+0x88/0x90 [<600295fd>] userspace+0x3fd/0x500 [<6001ac55>] fork_handler+0x85/0x90 $ addr2line -e vmlinux -i 0x602b3d18 include/linux/inetdevice.h:222 net/ipv4/fib_semantics.c:1264 Problem happens when RTNH_F_LINKDOWN is provided from user space when creating routes that do not use the flag, catched with netlink fuzzer. Currently, the kernel allows user space to set both flags to nh_flags and fib_flags but this is not intentional, the assumption was that they are not set. Fix this by rejecting both flags with EINVAL. Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Fixes: 0eeb075fad73 ("net: ipv4 sysctl option to ignore routes when nexthop link is down") Signed-off-by: Julian Anastasov <ja@ssi.bg> Cc: Andy Gospodarek <gospo@cumulusnetworks.com> Cc: Dinesh Dutt <ddutt@cumulusnetworks.com> Cc: Scott Feldman <sfeldma@gmail.com> Reviewed-by: Andy Gospodarek <gospo@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 80610229ef7b26615dbb6cb6e873709a60bacc9f ]

Vegard Nossum is reporting for a crash in fib_dump_info
when nh_dev = NULL and fib_nhs == 1:

Pid: 50, comm: netlink.exe Not tainted 4.7.0-rc5+
RIP: 0033:[<00000000602b3d18>]
RSP: 0000000062623890  EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000006261b800 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000024 RDI: 000000006245ba00
RBP: 00000000626238f0 R08: 000000000000029c R09: 0000000000000000
R10: 0000000062468038 R11: 000000006245ba00 R12: 000000006245ba00
R13: 00000000625f96c0 R14: 00000000601e16f0 R15: 0000000000000000
Kernel panic - not syncing: Kernel mode fault at addr 0x2e0, ip 0x602b3d18
CPU: 0 PID: 50 Comm: netlink.exe Not tainted 4.7.0-rc5+ #581
Stack:
 626238f0 960226a02 00000400 000000fe
 62623910 600afca7 62623970 62623a48
 62468038 00000018 00000000 00000000
Call Trace:
 [<602b3e93>] rtmsg_fib+0xd3/0x190
 [<602b6680>] fib_table_insert+0x260/0x500
 [<602b0e5d>] inet_rtm_newroute+0x4d/0x60
 [<60250def>] rtnetlink_rcv_msg+0x8f/0x270
 [<60267079>] netlink_rcv_skb+0xc9/0xe0
 [<60250d4b>] rtnetlink_rcv+0x3b/0x50
 [<60265400>] netlink_unicast+0x1a0/0x2c0
 [<60265e47>] netlink_sendmsg+0x3f7/0x470
 [<6021dc9a>] sock_sendmsg+0x3a/0x90
 [<6021e0d0>] ___sys_sendmsg+0x300/0x360
 [<6021fa64>] __sys_sendmsg+0x54/0xa0
 [<6021fac0>] SyS_sendmsg+0x10/0x20
 [<6001ea68>] handle_syscall+0x88/0x90
 [<600295fd>] userspace+0x3fd/0x500
 [<6001ac55>] fork_handler+0x85/0x90

$ addr2line -e vmlinux -i 0x602b3d18
include/linux/inetdevice.h:222
net/ipv4/fib_semantics.c:1264

Problem happens when RTNH_F_LINKDOWN is provided from user space
when creating routes that do not use the flag, catched with
netlink fuzzer.

Currently, the kernel allows user space to set both flags
to nh_flags and fib_flags but this is not intentional, the
assumption was that they are not set. Fix this by rejecting
both flags with EINVAL.

Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Fixes: 0eeb075fad73 ("net: ipv4 sysctl option to ignore routes when nexthop link is down")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Cc: Andy Gospodarek <gospo@cumulusnetworks.com>
Cc: Dinesh Dutt <ddutt@cumulusnetworks.com>
Cc: Scott Feldman <sfeldma@gmail.com>
Reviewed-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tcp: enable per-socket rate limiting of all 'challenge acks' 2016-08-16T07:30:47+00:00 Jason Baron jbaron@akamai.com 2016-07-14T15:38:40+00:00 5413f1a526d2d51d7a5768133c90936c017165c6 [ Upstream commit 083ae308280d13d187512b9babe3454342a7987e ] The per-socket rate limit for 'challenge acks' was introduced in the context of limiting ack loops: commit f2b2c582e824 ("tcp: mitigate ACK loops for connections as tcp_sock") And I think it can be extended to rate limit all 'challenge acks' on a per-socket basis. Since we have the global tcp_challenge_ack_limit, this patch allows for tcp_challenge_ack_limit to be set to a large value and effectively rely on the per-socket limit, or set tcp_challenge_ack_limit to a lower value and still prevents a single connections from consuming the entire challenge ack quota. It further moves in the direction of eliminating the global limit at some point, as Eric Dumazet has suggested. This a follow-up to: Subject: tcp: make challenge acks less predictable Cc: Eric Dumazet <edumazet@google.com> Cc: David S. Miller <davem@davemloft.net> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Yue Cao <ycao009@ucr.edu> Signed-off-by: Jason Baron <jbaron@akamai.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 083ae308280d13d187512b9babe3454342a7987e ]

The per-socket rate limit for 'challenge acks' was introduced in the
context of limiting ack loops:

commit f2b2c582e824 ("tcp: mitigate ACK loops for connections as tcp_sock")

And I think it can be extended to rate limit all 'challenge acks' on a
per-socket basis.

Since we have the global tcp_challenge_ack_limit, this patch allows for
tcp_challenge_ack_limit to be set to a large value and effectively rely on
the per-socket limit, or set tcp_challenge_ack_limit to a lower value and
still prevents a single connections from consuming the entire challenge ack
quota.

It further moves in the direction of eliminating the global limit at some
point, as Eric Dumazet has suggested. This a follow-up to:
Subject: tcp: make challenge acks less predictable

Cc: Eric Dumazet <edumazet@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Yue Cao <ycao009@ucr.edu>
Signed-off-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tcp: make challenge acks less predictable 2016-08-16T07:30:47+00:00 Eric Dumazet edumazet@google.com 2016-07-10T08:04:02+00:00 72c2d3bccaba4a0a4de354f9d2d24eccd05bfccf [ Upstream commit 75ff39ccc1bd5d3c455b6822ab09e533c551f758 ] Yue Cao claims that current host rate limiting of challenge ACKS (RFC 5961) could leak enough information to allow a patient attacker to hijack TCP sessions. He will soon provide details in an academic paper. This patch increases the default limit from 100 to 1000, and adds some randomization so that the attacker can no longer hijack sessions without spending a considerable amount of probes. Based on initial analysis and patch from Linus. Note that we also have per socket rate limiting, so it is tempting to remove the host limit in the future. v2: randomize the count of challenge acks per second, not the period. Fixes: 282f23c6ee34 ("tcp: implement RFC 5961 3.2") Reported-by: Yue Cao <ycao009@ucr.edu> Signed-off-by: Eric Dumazet <edumazet@google.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 75ff39ccc1bd5d3c455b6822ab09e533c551f758 ]

Yue Cao claims that current host rate limiting of challenge ACKS
(RFC 5961) could leak enough information to allow a patient attacker
to hijack TCP sessions. He will soon provide details in an academic
paper.

This patch increases the default limit from 100 to 1000, and adds
some randomization so that the attacker can no longer hijack
sessions without spending a considerable amount of probes.

Based on initial analysis and patch from Linus.

Note that we also have per socket rate limiting, so it is tempting
to remove the host limit in the future.

v2: randomize the count of challenge acks per second, not the period.

Fixes: 282f23c6ee34 ("tcp: implement RFC 5961 3.2")
Reported-by: Yue Cao <ycao009@ucr.edu>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipmr/ip6mr: Initialize the last assert time of mfc entries. 2016-07-11T16:31:11+00:00 Tom Goff thomas.goff@ll.mit.edu 2016-06-23T20:11:57+00:00 d05916086fa3e797b3806f1ec3c5a923adb3070e [ Upstream commit 70a0dec45174c976c64b4c8c1d0898581f759948 ] This fixes wrong-interface signaling on 32-bit platforms for entries created when jiffies > 2^31 + MFC_ASSERT_THRESH. Signed-off-by: Tom Goff <thomas.goff@ll.mit.edu> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 70a0dec45174c976c64b4c8c1d0898581f759948 ]

This fixes wrong-interface signaling on 32-bit platforms for entries
created when jiffies > 2^31 + MFC_ASSERT_THRESH.

Signed-off-by: Tom Goff <thomas.goff@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>