linux.git/drivers/net/usb/ipheth.c, branch v5.3

usbnet: ipheth: fix racing condition

2019-05-21T20:10:52+00:00

Fix a racing condition in ipheth.c that can lead to slow performance.

Bug: In ipheth_tx(), netif_wake_queue() may be called on the callback
ipheth_sndbulk_callback(), _before_ netif_stop_queue() is called.
When this happens, the queue is stopped longer than it needs to be,
thus reducing network performance.

Fix: Move netif_stop_queue() in front of usb_submit_urb(). Now the order
is always correct. In case, usb_submit_urb() fails, the queue is woken up
again as callback will not fire.

Testing: This racing condition is usually not noticeable, as it has to
occur very frequently to slowdown the network. The callback from the USB
is usually triggered slow enough, so the situation does not appear.
However, on a Ubuntu Linux on VMWare Workstation, running on Windows 10,
the we loose the race quite often and the following speedup can be noticed:

Without this patch: Download:  4.10 Mbit/s, Upload:  4.01 Mbit/s
With this patch:    Download: 36.23 Mbit/s, Upload: 17.61 Mbit/s

Signed-off-by: Oliver Zweigle 
Signed-off-by: Bernd Eckstein <3ernd.Eckstein@gmail.com>
Signed-off-by: David S. Miller

usbnet: ipheth: Remove unnecessary NULL pointer check

2019-05-04T03:59:31+00:00

ipheth_carrier_set() is called from two locations. In
ipheth_carrier_check_work(), its parameter 'dev' is set with
container_of(work, ...) and can not be NULL. In ipheth_open(),
dev is extracted from netdev_priv(net) and dereferenced before
the call to ipheth_carrier_set(). The NULL pointer check of dev
in ipheth_carrier_set() is therefore unnecessary and can be removed.

Cc: Gustavo A. R. Silva 
Signed-off-by: Guenter Roeck 
Signed-off-by: David S. Miller

usbnet: ipheth: Simplify device detection

2019-04-26T15:34:01+00:00

All Apple products use the same protocol for tethering over USB.
To simplify the code and make it future proof, use
USB_VENDOR_AND_INTERFACE_INFO() instead of
USB_DEVICE_AND_INTERFACE_INFO() to automatically detect and support
all existing and future Apple products using the same interface.

Signed-off-by: Guenter Roeck 
Signed-off-by: David S. Miller

usbnet: ipheth: fix potential recvmsg bug and recvmsg bug 2

2018-11-27T22:57:16+00:00

The bug is not easily reproducable, as it may occur very infrequently
(we had machines with 20minutes heavy downloading before it occurred)
However, on a virual machine (VMWare on Windows 10 host) it occurred
pretty frequently (1-2 seconds after a speedtest was started)

dev->tx_skb mab be freed via dev_kfree_skb_irq on a callback
before it is set.

This causes the following problems:
- double free of the skb or potential memory leak
- in dmesg: 'recvmsg bug' and 'recvmsg bug 2' and eventually
  general protection fault

Example dmesg output:
[  134.841986] ------------[ cut here ]------------
[  134.841987] recvmsg bug: copied 9C24A555 seq 9C24B557 rcvnxt 9C25A6B3 fl 0
[  134.841993] WARNING: CPU: 7 PID: 2629 at /build/linux-hwe-On9fm7/linux-hwe-4.15.0/net/ipv4/tcp.c:1865 tcp_recvmsg+0x44d/0xab0
[  134.841994] Modules linked in: ipheth(OE) kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd glue_helper cryptd vmw_balloon intel_rapl_perf joydev input_leds serio_raw vmw_vsock_vmci_transport vsock shpchp i2c_piix4 mac_hid binfmt_misc vmw_vmci parport_pc ppdev lp parport autofs4 vmw_pvscsi vmxnet3 hid_generic usbhid hid vmwgfx ttm drm_kms_helper syscopyarea sysfillrect mptspi mptscsih sysimgblt ahci psmouse fb_sys_fops pata_acpi mptbase libahci e1000 drm scsi_transport_spi
[  134.842046] CPU: 7 PID: 2629 Comm: python Tainted: G        W  OE    4.15.0-34-generic #37~16.04.1-Ubuntu
[  134.842046] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017
[  134.842048] RIP: 0010:tcp_recvmsg+0x44d/0xab0
[  134.842048] RSP: 0018:ffffa6630422bcc8 EFLAGS: 00010286
[  134.842049] RAX: 0000000000000000 RBX: ffff997616f4f200 RCX: 0000000000000006
[  134.842049] RDX: 0000000000000007 RSI: 0000000000000082 RDI: ffff9976257d6490
[  134.842050] RBP: ffffa6630422bd98 R08: 0000000000000001 R09: 000000000004bba4
[  134.842050] R10: 0000000001e00c6f R11: 000000000004bba4 R12: ffff99760dee3000
[  134.842051] R13: 0000000000000000 R14: ffff99760dee3514 R15: 0000000000000000
[  134.842051] FS:  00007fe332347700(0000) GS:ffff9976257c0000(0000) knlGS:0000000000000000
[  134.842052] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  134.842053] CR2: 0000000001e41000 CR3: 000000020e9b4006 CR4: 00000000003606e0
[  134.842055] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  134.842055] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  134.842057] Call Trace:
[  134.842060]  ? aa_sk_perm+0x53/0x1a0
[  134.842064]  inet_recvmsg+0x51/0xc0
[  134.842066]  sock_recvmsg+0x43/0x50
[  134.842070]  SYSC_recvfrom+0xe4/0x160
[  134.842072]  ? __schedule+0x3de/0x8b0
[  134.842075]  ? ktime_get_ts64+0x4c/0xf0
[  134.842079]  SyS_recvfrom+0xe/0x10
[  134.842082]  do_syscall_64+0x73/0x130
[  134.842086]  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[  134.842086] RIP: 0033:0x7fe331f5a81d
[  134.842088] RSP: 002b:00007ffe8da98398 EFLAGS: 00000246 ORIG_RAX: 000000000000002d
[  134.842090] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 00007fe331f5a81d
[  134.842094] RDX: 00000000000003fb RSI: 0000000001e00874 RDI: 0000000000000003
[  134.842095] RBP: 00007fe32f642c70 R08: 0000000000000000 R09: 0000000000000000
[  134.842097] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe332347698
[  134.842099] R13: 0000000001b7e0a0 R14: 0000000001e00874 R15: 0000000000000000
[  134.842103] Code: 24 fd ff ff e9 cc fe ff ff 48 89 d8 41 8b 8c 24 10 05 00 00 44 8b 45 80 48 c7 c7 08 bd 59 8b 48 89 85 68 ff ff ff e8 b3 c4 7d ff <0f> 0b 48 8b 85 68 ff ff ff e9 e9 fe ff ff 41 8b 8c 24 10 05 00
[  134.842126] ---[ end trace b7138fc08c83147f ]---
[  134.842144] general protection fault: 0000 [#1] SMP PTI
[  134.842145] Modules linked in: ipheth(OE) kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd glue_helper cryptd vmw_balloon intel_rapl_perf joydev input_leds serio_raw vmw_vsock_vmci_transport vsock shpchp i2c_piix4 mac_hid binfmt_misc vmw_vmci parport_pc ppdev lp parport autofs4 vmw_pvscsi vmxnet3 hid_generic usbhid hid vmwgfx ttm drm_kms_helper syscopyarea sysfillrect mptspi mptscsih sysimgblt ahci psmouse fb_sys_fops pata_acpi mptbase libahci e1000 drm scsi_transport_spi
[  134.842161] CPU: 7 PID: 2629 Comm: python Tainted: G        W  OE    4.15.0-34-generic #37~16.04.1-Ubuntu
[  134.842162] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017
[  134.842164] RIP: 0010:tcp_close+0x2c6/0x440
[  134.842165] RSP: 0018:ffffa6630422bde8 EFLAGS: 00010202
[  134.842167] RAX: 0000000000000000 RBX: ffff99760dee3000 RCX: 0000000180400034
[  134.842168] RDX: 5c4afd407207a6c4 RSI: ffffe868495bd300 RDI: ffff997616f4f200
[  134.842169] RBP: ffffa6630422be08 R08: 0000000016f4d401 R09: 0000000180400034
[  134.842169] R10: ffffa6630422bd98 R11: 0000000000000000 R12: 000000000000600c
[  134.842170] R13: 0000000000000000 R14: ffff99760dee30c8 R15: ffff9975bd44fe00
[  134.842171] FS:  00007fe332347700(0000) GS:ffff9976257c0000(0000) knlGS:0000000000000000
[  134.842173] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  134.842174] CR2: 0000000001e41000 CR3: 000000020e9b4006 CR4: 00000000003606e0
[  134.842177] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  134.842178] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  134.842179] Call Trace:
[  134.842181]  inet_release+0x42/0x70
[  134.842183]  __sock_release+0x42/0xb0
[  134.842184]  sock_close+0x15/0x20
[  134.842187]  __fput+0xea/0x220
[  134.842189]  ____fput+0xe/0x10
[  134.842191]  task_work_run+0x8a/0xb0
[  134.842193]  exit_to_usermode_loop+0xc4/0xd0
[  134.842195]  do_syscall_64+0xf4/0x130
[  134.842197]  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[  134.842197] RIP: 0033:0x7fe331f5a560
[  134.842198] RSP: 002b:00007ffe8da982e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
[  134.842200] RAX: 0000000000000000 RBX: 00007fe32f642c70 RCX: 00007fe331f5a560
[  134.842201] RDX: 00000000008f5320 RSI: 0000000001cd4b50 RDI: 0000000000000003
[  134.842202] RBP: 00007fe32f6500f8 R08: 000000000000003c R09: 00000000009343c0
[  134.842203] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe32f6500d0
[  134.842204] R13: 00000000008f5320 R14: 00000000008f5320 R15: 0000000001cd4770
[  134.842205] Code: c8 00 00 00 45 31 e4 49 39 fe 75 4d eb 50 83 ab d8 00 00 00 01 48 8b 17 48 8b 47 08 48 c7 07 00 00 00 00 48 c7 47 08 00 00 00 00 <48> 89 42 08 48 89 10 0f b6 57 34 8b 47 2c 2b 47 28 83 e2 01 80
[  134.842226] RIP: tcp_close+0x2c6/0x440 RSP: ffffa6630422bde8
[  134.842227] ---[ end trace b7138fc08c831480 ]---

The proposed patch eliminates a potential racing condition.
Before, usb_submit_urb was called and _after_ that, the skb was attached
(dev->tx_skb). So, on a callback it was possible, however unlikely that the
skb was freed before it was set. That way (because dev->tx_skb was not set
to NULL after it was freed), it could happen that a skb from a earlier
transmission was freed a second time (and the skb we should have freed did
not get freed at all)

Now we free the skb directly in ipheth_tx(). It is not passed to the
callback anymore, eliminating the posibility of a double free of the same
skb. Depending on the retval of usb_submit_urb() we use dev_kfree_skb_any()
respectively dev_consume_skb_any() to free the skb.

Signed-off-by: Oliver Zweigle 
Signed-off-by: Bernd Eckstein <3ernd.Eckstein@gmail.com>
Signed-off-by: David S. Miller

usbnet: ipheth: fix potential null pointer dereference in ipheth_carrier_set

2017-11-19T03:23:57+00:00

_dev_ is being dereferenced before it is null checked, hence there
is a potential null pointer dereference.

Fix this by moving the pointer dereference after _dev_ has been null
checked.

Addresses-Coverity-ID: 1462020
Fixes: bb1b40c7cb86 ("usbnet: ipheth: prevent TX queue timeouts when device not ready")
Signed-off-by: Gustavo A. R. Silva 
Signed-off-by: David S. Miller

usbnet: ipheth: prevent TX queue timeouts when device not ready

2017-11-15T04:51:46+00:00

iOS devices require the host to be "trusted" before servicing network
packets. Establishing trust requires the user to confirm a dialog on the
iOS device.Until trust is established, the iOS device will silently discard
network packets from the host. Currently, the ipheth driver does not detect
whether an iOS device has established trust with the host, and immediately
sets up the transmit queues.

This causes the following problems:

- Kernel taint due to WARN() in netdev watchdog.
- Dmesg spam ("TX timeout").
- Disruption of user space networking activity (dhcpd, etc...) when new
interface comes up but cannot be used.
- Unnecessary host and device wakeups and USB traffic

Example dmesg output:

[ 1101.319778] NETDEV WATCHDOG: eth1 (ipheth): transmit queue 0 timed out
[ 1101.319817] ------------[ cut here ]------------
[ 1101.319828] WARNING: CPU: 0 PID: 0 at net/sched/sch_generic.c:316 dev_watchdog+0x20f/0x220
[ 1101.319831] Modules linked in: ipheth usbmon nvidia_drm(PO) nvidia_modeset(PO) nvidia(PO) iwlmvm mac80211 iwlwifi btusb btrtl btbcm btintel qmi_wwan bluetooth cfg80211 ecdh_generic thinkpad_acpi rfkill [last unloaded: ipheth]
[ 1101.319861] CPU: 0 PID: 0 Comm: swapper/0 Tainted: P           O    4.13.12.1 #1
[ 1101.319864] Hardware name: LENOVO 20ENCTO1WW/20ENCTO1WW, BIOS N1EET62W (1.35 ) 11/10/2016
[ 1101.319867] task: ffffffff81e11500 task.stack: ffffffff81e00000
[ 1101.319873] RIP: 0010:dev_watchdog+0x20f/0x220
[ 1101.319876] RSP: 0018:ffff8810a3c03e98 EFLAGS: 00010292
[ 1101.319880] RAX: 000000000000003a RBX: 0000000000000000 RCX: 0000000000000000
[ 1101.319883] RDX: ffff8810a3c15c48 RSI: ffffffff81ccbfc2 RDI: 00000000ffffffff
[ 1101.319886] RBP: ffff880c04ebc41c R08: 0000000000000000 R09: 0000000000000379
[ 1101.319889] R10: 00000100696589d0 R11: 0000000000000378 R12: ffff880c04ebc000
[ 1101.319892] R13: 0000000000000000 R14: 0000000000000001 R15: ffff880c2865fc80
[ 1101.319896] FS:  0000000000000000(0000) GS:ffff8810a3c00000(0000) knlGS:0000000000000000
[ 1101.319899] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1101.319902] CR2: 00007f3ff24ac000 CR3: 0000000001e0a000 CR4: 00000000003406f0
[ 1101.319905] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1101.319908] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1101.319910] Call Trace:
[ 1101.319914]  
[ 1101.319921]  ? dev_graft_qdisc+0x70/0x70
[ 1101.319928]  ? dev_graft_qdisc+0x70/0x70
[ 1101.319934]  ? call_timer_fn+0x2e/0x170
[ 1101.319939]  ? dev_graft_qdisc+0x70/0x70
[ 1101.319944]  ? run_timer_softirq+0x1ea/0x440
[ 1101.319951]  ? timerqueue_add+0x54/0x80
[ 1101.319956]  ? enqueue_hrtimer+0x38/0xa0
[ 1101.319963]  ? __do_softirq+0xed/0x2e7
[ 1101.319970]  ? irq_exit+0xb4/0xc0
[ 1101.319976]  ? smp_apic_timer_interrupt+0x39/0x50
[ 1101.319981]  ? apic_timer_interrupt+0x8c/0xa0
[ 1101.319983]  
[ 1101.319992]  ? cpuidle_enter_state+0xfa/0x2a0
[ 1101.319999]  ? do_idle+0x1a3/0x1f0
[ 1101.320004]  ? cpu_startup_entry+0x5f/0x70
[ 1101.320011]  ? start_kernel+0x444/0x44c
[ 1101.320017]  ? early_idt_handler_array+0x120/0x120
[ 1101.320023]  ? x86_64_start_kernel+0x145/0x154
[ 1101.320028]  ? secondary_startup_64+0x9f/0x9f
[ 1101.320033] Code: 20 04 00 00 eb 9f 4c 89 e7 c6 05 59 44 71 00 01 e8 a7 df fd ff 89 d9 4c 89 e6 48 c7 c7 70 b7 cd 81 48 89 c2 31 c0 e8 97 64 90 ff <0f> ff eb bf 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00
[ 1101.320103] ---[ end trace 0cc4d251e2b57080 ]---
[ 1101.320110] ipheth 1-5:4.2: ipheth_tx_timeout: TX timeout

The last message "TX timeout" is repeated every 5 seconds until trust is
established or the device is disconnected, filling up dmesg.

The proposed patch eliminates the problem by, upon connection, keeping the
TX queue and carrier disabled until a packet is first received from the iOS
device. This is reflected by the confirmed_pairing variable in the device
structure. Only after at least one packet has been received from the iOS
device, the transmit queue and carrier are brought up during the periodic
device poll in ipheth_carrier_set. Because the iOS device will always send
a packet immediately upon trust being established, this should not delay
the interface becoming useable. To prevent failed UBRs in
ipheth_rcvbulk_callback from perpetually re-enabling the queue if it was
disabled, a new check is added so only successful transfers re-enable the
queue, whereas failed transfers only trigger an immediate poll.

This has the added benefit of removing the periodic control requests to the
iOS device until trust has been established and thus should reduce wakeup
events on both the host and the iOS device.

Signed-off-by: Alexander Kappner 
Signed-off-by: David S. Miller

net: usb: ipheth: constify usb_device_id

2017-08-09T00:47:58+00:00

usb_device_id are not supposed to change at runtime. All functions
working with usb_device_id provided by  work with
const usb_device_id. So mark the non-const structs as const.

Signed-off-by: Arvind Yadav 
Signed-off-by: David S. Miller

networking: introduce and use skb_put_data()

2017-06-16T15:48:37+00:00

A common pattern with skb_put() is to just want to memcpy()
some data into the new space, introduce skb_put_data() for
this.

An spatch similar to the one for skb_put_zero() converts many
of the places using it:

    @@
    identifier p, p2;
    expression len, skb, data;
    type t, t2;
    @@
    (
    -p = skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    |
    -p = (t)skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, len);
    |
    -memcpy(p, data, len);
    )

    @@
    type t, t2;
    identifier p, p2;
    expression skb, data;
    @@
    t *p;
    ...
    (
    -p = skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    |
    -p = (t *)skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, sizeof(*p));
    |
    -memcpy(p, data, sizeof(*p));
    )

    @@
    expression skb, len, data;
    @@
    -memcpy(skb_put(skb, len), data, len);
    +skb_put_data(skb, data, len);

(again, manually post-processed to retain some comments)

Reviewed-by: Stephen Hemminger 
Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2014-06-04T06:32:12+00:00

Conflicts:
	include/net/inetpeer.h
	net/ipv6/output_core.c

Changes in net were fixing bugs in code removed in net-next.

Signed-off-by: David S. Miller

ipheth: Add support for iPad 2 and iPad 3

2014-06-02T23:11:55+00:00

Each iPad model has a different product id, this patch adds support for iPad 2
(pid 0x12a2) and iPad 3 (pid 0x12a6). Note that iPad 2 must be jailbroken and a
third-party app must be used for tethering to work. On iPad 3, tethering works
out of the box (assuming your ISP is nice).

Signed-off-by: Kristian Evensen 
Signed-off-by: David S. Miller