net/usbnet: avoid recursive locking in usbnet_stop()
authorSteve Lin <>
Wed, 22 Aug 2012 21:55:34 +0000 (14:55 -0700)
committerSimone Willett <>
Thu, 23 Aug 2012 21:46:03 +0000 (14:46 -0700)
net/usbnet: avoid recursive locking in usbnet_stop()

|kernel BUG at kernel/rtmutex.c:724!
|[<c029599c>] (rt_spin_lock_slowlock+0x108/0x2bc) from [<c01c2330>] (defer_bh+0x1c/0xb4)
|[<c01c2330>] (defer_bh+0x1c/0xb4) from [<c01c3afc>] (rx_complete+0x14c/0x194)
|[<c01c3afc>] (rx_complete+0x14c/0x194) from [<c01cac88>] (usb_hcd_giveback_urb+0xa0/0xf0)
|[<c01cac88>] (usb_hcd_giveback_urb+0xa0/0xf0) from [<c01e1ff4>] (musb_giveback+0x34/0x40)
|[<c01e1ff4>] (musb_giveback+0x34/0x40) from [<c01e2b1c>] (musb_advance_schedule+0xb4/0x1c0)
|[<c01e2b1c>] (musb_advance_schedule+0xb4/0x1c0) from [<c01e2ca8>] (musb_cleanup_urb.isra.9+0x80/0x8c)
|[<c01e2ca8>] (musb_cleanup_urb.isra.9+0x80/0x8c) from [<c01e2ed0>] (musb_urb_dequeue+0xec/0x108)
|[<c01e2ed0>] (musb_urb_dequeue+0xec/0x108) from [<c01cbb90>] (unlink1+0xbc/0xcc)
|[<c01cbb90>] (unlink1+0xbc/0xcc) from [<c01cc2ec>] (usb_hcd_unlink_urb+0x54/0xa8)
|[<c01cc2ec>] (usb_hcd_unlink_urb+0x54/0xa8) from [<c01c2a84>] (unlink_urbs.isra.17+0x2c/0x58)
|[<c01c2a84>] (unlink_urbs.isra.17+0x2c/0x58) from [<c01c2b44>] (usbnet_terminate_urbs+0x94/0x10c)
|[<c01c2b44>] (usbnet_terminate_urbs+0x94/0x10c) from [<c01c2d68>] (usbnet_stop+0x100/0x15c)
|[<c01c2d68>] (usbnet_stop+0x100/0x15c) from [<c020f718>] (__dev_close_many+0x94/0xc8)

defer_bh() takes the lock which is hold during unlink_urbs(). The safe
walk suggest that the skb will be removed from the list and this is done
by defer_bh() so it seems to be okay to drop the lock here.

Reported-by: AnÃ\255bal Almeida Pinto <>
Signed-off-by: Sebastian Andrzej Siewior <>
Acked-by: Oliver Neukum <>
Signed-off-by: David S. Miller <>
(cherry picked from commit 4231d47e6fe69f061f96c98c30eaf9fb4c14b96d)
net/usbnet: reserve headroom on rx skbs

network drivers should reserve some headroom on incoming skbs so that we
dont need expensive reallocations, eg forwarding packets in tunnels.

This NET_SKB_PAD padding is done in various helpers, like
__netdev_alloc_skb_ip_align() in this patch, combining NET_SKB_PAD and

Signed-off-by: Eric Dumazet <>
Cc: Oliver Neukum <>
Cc: Greg Kroah-Hartman <>
Acked-by: Oliver Neukum <>
Signed-off-by: David S. Miller <>
(cherry picked from commit 7bdd402706cf26bfef9050dfee3f229b7f33ee4f)
usbnet: use netif_tx_wake_queue instead of netif_start_queue

If host is going to autosuspend function with two interfaces and
if IP packet has arrived in-between of two usbnet_suspend() callbacks,
i.e usbnet_resume() is called in-between, tx data flow is stopped.
When autosuspend timer expires and device is put to autosuspend
again, tx queue is waked up and data can be sent again.
This behavior might be repeated several times in a row.

Tested on Intel/ARM.

Reviewed-by: Sjur Brændeland <>
Tested-by: Dmitry Tarnyagin <>
Signed-off-by: Alexey Orishko <>
Acked-by: Oliver Neukum <>
Signed-off-by: David S. Miller <>
(cherry picked from commit 1aa9bc5b2f4cf8c48944fb9a607bf1dd674e2c10)
usbnet: increase URB reference count before usb_unlink_urb

Commit 4231d47e6fe69f061f96c98c30eaf9fb4c14b96d(net/usbnet: avoid
recursive locking in usbnet_stop()) fixes the recursive locking
problem by releasing the skb queue lock, but it makes usb_unlink_urb
racing with defer_bh, and the URB to being unlinked may be freed before
or during calling usb_unlink_urb, so use-after-free problem may be
triggerd inside usb_unlink_urb.

The patch fixes the use-after-free problem by increasing URB
reference count with skb queue lock held before calling
usb_unlink_urb, so the URB won't be freed until return from

Reported-by: Dave Jones <>
Signed-off-by: Ming Lei <>
Acked-by: Greg Kroah-Hartman <>
Signed-off-by: David S. Miller <>
(cherry picked from commit 0956a8c20b23d429e79ff86d4325583fc06f9eb4)
usbnet: don't clear urb->dev in tx_complete

URB unlinking is always racing with its completion and tx_complete
may be called before or during running usb_unlink_urb, so tx_complete
must not clear urb->dev since it will be used in unlink path,
otherwise invalid memory accesses or usb device leak may be caused
inside usb_unlink_urb.

Signed-off-by: Ming Lei <>
Acked-by: Greg Kroah-Hartman <>
Signed-off-by: David S. Miller <>
(cherry picked from commit 5d5440a835710d09f0ef18da5000541ec98b537a)
usbnet: consider device busy at each recieved packet

usbnet should centrally handle busy reporting in the rx path
so subdrivers need not worry. This hurts use cases which do
rx only or predominantly.

Signed-off-by: Oliver Neukum <>
Signed-off-by: David S. Miller <>
(cherry picked from commit 8a78335442cea429afb2b964318b6e257448ea00)
usbnet: fix leak of transfer buffer of dev->interrupt

The transfer buffer of dev->interrupt is allocated in .probe path,
but not freed in .disconnet path, so mark the interrupt URB as
URB_FREE_BUFFER to free the buffer when the URB is destroyed.

Signed-off-by: Ming Lei <>
Acked-by: Oliver Neukum <>
Signed-off-by: David S. Miller <>
(cherry picked from commit 267a83e8e00dc5a878b24c39883643c20a8b1482)

Bug 1036768

Change-Id: I5d6620c8ff4e6cef52c3f467fb2196658c4d47b1
Signed-off-by: Steve Lin <>
Reviewed-on: http://git-master/r/125338
GVS: Gerrit_Virtual_Submit