linux-stable.git/drivers/usb/core/devio.c, branch linux-3.2.y

USB: usbfs: Filter flags passed in from user space

2018-03-03T15:50:40+00:00

commit 446f666da9f019ce2ffd03800995487e79a91462 upstream.

USBDEVFS_URB_ISO_ASAP must be accepted only for ISO endpoints.
Improve sanity checking.

Reported-by: Andrey Konovalov 
Signed-off-by: Oliver Neukum 
Acked-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

USB: usbfs: compute urb->actual_length for isochronous

2018-02-13T18:32:14+00:00

commit 2ef47001b3ee3ded579b7532ebdcf8680e4d8c54 upstream.

The USB kerneldoc says that the actual_length field "is read in
non-iso completion functions", but the usbfs driver uses it for all
URB types in processcompl().  Since not all of the host controller
drivers set actual_length for isochronous URBs, programs using usbfs
with some host controllers don't work properly.  For example, Minas
reports that a USB camera controlled by libusb doesn't work properly
with a dwc2 controller.

It doesn't seem worthwhile to change the HCDs and the documentation,
since the in-kernel USB class drivers evidently don't rely on
actual_length for isochronous transfers.  The easiest solution is for
usbfs to calculate the actual_length value for itself, by adding up
the lengths of the individual packets in an isochronous transfer.

Signed-off-by: Alan Stern 
CC: Minas Harutyunyan 
Reported-and-tested-by: wlf 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

USB: core: Avoid race of async_completed() w/ usbdev_release()

2017-11-26T13:51:04+00:00

commit ed62ca2f4f51c17841ea39d98c0c409cb53a3e10 upstream.

While running reboot tests w/ a specific set of USB devices (and
slub_debug enabled), I found that once every few hours my device would
be crashed with a stack that looked like this:

[   14.012445] BUG: spinlock bad magic on CPU#0, modprobe/2091
[   14.012460]  lock: 0xffffffc0cb055978, .magic: ffffffc0, .owner: cryption contexts: %lu/%lu
[   14.012460] /1025536097, .owner_cpu: 0
[   14.012466] CPU: 0 PID: 2091 Comm: modprobe Not tainted 4.4.79 #352
[   14.012468] Hardware name: Google Kevin (DT)
[   14.012471] Call trace:
[   14.012483] [<....>] dump_backtrace+0x0/0x160
[   14.012487] [<....>] show_stack+0x20/0x28
[   14.012494] [<....>] dump_stack+0xb4/0xf0
[   14.012500] [<....>] spin_dump+0x8c/0x98
[   14.012504] [<....>] spin_bug+0x30/0x3c
[   14.012508] [<....>] do_raw_spin_lock+0x40/0x164
[   14.012515] [<....>] _raw_spin_lock_irqsave+0x64/0x74
[   14.012521] [<....>] __wake_up+0x2c/0x60
[   14.012528] [<....>] async_completed+0x2d0/0x300
[   14.012534] [<....>] __usb_hcd_giveback_urb+0xc4/0x138
[   14.012538] [<....>] usb_hcd_giveback_urb+0x54/0xf0
[   14.012544] [<....>] xhci_irq+0x1314/0x1348
[   14.012548] [<....>] usb_hcd_irq+0x40/0x50
[   14.012553] [<....>] handle_irq_event_percpu+0x1b4/0x3f0
[   14.012556] [<....>] handle_irq_event+0x4c/0x7c
[   14.012561] [<....>] handle_fasteoi_irq+0x158/0x1c8
[   14.012564] [<....>] generic_handle_irq+0x30/0x44
[   14.012568] [<....>] __handle_domain_irq+0x90/0xbc
[   14.012572] [<....>] gic_handle_irq+0xcc/0x18c

Investigation using kgdb() found that the wait queue that was passed
into wake_up() had been freed (it was filled with slub_debug poison).

I analyzed and instrumented the code and reproduced.  My current
belief is that this is happening:

1. async_completed() is called (from IRQ).  Moves "as" onto the
   completed list.
2. On another CPU, proc_reapurbnonblock_compat() calls
   async_getcompleted().  Blocks on spinlock.
3. async_completed() releases the lock; keeps running; gets blocked
   midway through wake_up().
4. proc_reapurbnonblock_compat() => async_getcompleted() gets the
   lock; removes "as" from completed list and frees it.
5. usbdev_release() is called.  Frees "ps".
6. async_completed() finally continues running wake_up().  ...but
   wake_up() has a pointer to the freed "ps".

The instrumentation that led me to believe this was based on adding
some trace_printk() calls in a select few functions and then using
kdb's "ftdump" at crash time.  The trace follows (NOTE: in the trace
below I cheated a little bit and added a udelay(1000) in
async_completed() after releasing the spinlock because I wanted it to
trigger quicker):

<...>-2104   0d.h2 13759034us!: async_completed at start: as=ffffffc0cc638200
mtpd-2055    3.... 13759356us : async_getcompleted before spin_lock_irqsave
mtpd-2055    3d..1 13759362us : async_getcompleted after list_del_init: as=ffffffc0cc638200
mtpd-2055    3.... 13759371us+: proc_reapurbnonblock_compat: free_async(ffffffc0cc638200)
mtpd-2055    3.... 13759422us+: async_getcompleted before spin_lock_irqsave
mtpd-2055    3.... 13759479us : usbdev_release at start: ps=ffffffc0cc042080
mtpd-2055    3.... 13759487us : async_getcompleted before spin_lock_irqsave
mtpd-2055    3.... 13759497us!: usbdev_release after kfree(ps): ps=ffffffc0cc042080
<...>-2104   0d.h2 13760294us : async_completed before wake_up(): as=ffffffc0cc638200

To fix this problem we can just move the wake_up() under the ps->lock.
There should be no issues there that I'm aware of.

Signed-off-by: Douglas Anderson 
Acked-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

USB: core: replace %p with %pK

2017-09-15T17:30:42+00:00

commit 2f964780c03b73de269b08d12aff96a9618d13f3 upstream.

Format specifier %p can leak kernel addresses while not valuing the
kptr_restrict system settings. When kptr_restrict is set to (1), kernel
pointers printed using the %pK format specifier will be replaced with
Zeros. Debugging Note : &pK prints only Zeros as address. If you need
actual address information, write 0 to kptr_restrict.

echo 0 > /proc/sys/kernel/kptr_restrict

[Found by poking around in a random vendor kernel tree, it would be nice
if someone would actually send these types of patches upstream - gkh]

Signed-off-by: Vamsi Krishna Samavedam 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.2: drop changes in proc_reapurb*(), usbdev_do_ioctl(),
 usb_submit_urb()]
Signed-off-by: Ben Hutchings

USB: avoid left shift by -1

2016-11-20T01:01:34+00:00

commit 53e5f36fbd2453ad69a3369a1db62dc06c30a4aa upstream.

UBSAN complains about a left shift by -1 in proc_do_submiturb().  This
can occur when an URB is submitted for a bulk or control endpoint on
a high-speed device, since the code doesn't bother to check the
endpoint type; normally only interrupt or isochronous endpoints have
a nonzero bInterval value.

Aside from the fact that the operation is illegal, it shouldn't matter
because the result isn't used.  Still, in theory it could cause a
hardware exception or other problem, so we should work around it.
This patch avoids doing the left shift unless the shift amount is >= 0.

The same piece of code has another problem.  When checking the device
speed (the exponential encoding for interrupt endpoints is used only
by high-speed or faster devices), we need to look for speed >=
USB_SPEED_SUPER as well as speed == USB_SPEED HIGH.  The patch adds
this check.

Signed-off-by: Alan Stern 
Reported-by: Vittorio Zecca 
Tested-by: Vittorio Zecca 
Suggested-by: Bjørn Mork 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

USB: usbfs: fix potential infoleak in devio

2016-08-22T21:37:18+00:00

commit 681fef8380eb818c0b845fca5d2ab1dcbab114ee upstream.

The stack object “ci” has a total size of 8 bytes. Its last 3 bytes
are padding bytes which are not initialized and leaked to userland
via “copy_to_user”.

Signed-off-by: Kangjie Lu 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

USB: usbfs: don't leak kernel data in siginfo

2015-05-09T22:16:21+00:00

commit f0c2b68198589249afd2b1f2c4e8de8c03e19c16 upstream.

When a signal is delivered, the information in the siginfo structure
is copied to userspace.  Good security practice dicatates that the
unused fields in this structure should be initialized to 0 so that
random kernel stack data isn't exposed to the user.  This patch adds
such an initialization to the two places where usbfs raises signals.

Signed-off-by: Alan Stern 
Reported-by: Dave Mielke 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

usb/core/devio.c: Don't reject control message to endpoint with wrong direction bit

2013-10-26T20:06:06+00:00

commit 831abf76643555a99b80a3b54adfa7e4fa0a3259 upstream.

Trying to read data from the Pegasus Technologies NoteTaker (0e20:0101)
[1] with the Windows App (EasyNote) works natively but fails when
Windows is running under KVM (and the USB device handed to KVM).

The reason is a USB control message
 usb 4-2.2: control urb: bRequestType=22 bRequest=09 wValue=0200 wIndex=0001 wLength=0008
This goes to endpoint address 0x01 (wIndex); however, endpoint address
0x01 does not exist. There is an endpoint 0x81 though (same number,
but other direction); the app may have meant that endpoint instead.

The kernel thus rejects the IO and thus we see the failure.

Apparently, Linux is more strict here than Windows ... we can't change
the Win app easily, so that's a problem.

It seems that the Win app/driver is buggy here and the driver does not
behave fully according to the USB HID class spec that it claims to
belong to.  The device seems to happily deal with that though (and
seems to not really care about this value much).

So the question is whether the Linux kernel should filter here.
Rejecting has the risk that somewhat non-compliant userspace apps/
drivers (most likely in a virtual machine) are prevented from working.
Not rejecting has the risk of confusing an overly sensitive device with
such a transfer. Given the fact that Windows does not filter it makes
this risk rather small though.

The patch makes the kernel more tolerant: If the endpoint address in
wIndex does not exist, but an endpoint with toggled direction bit does,
it will let the transfer through. (It does NOT change the message.)

With attached patch, the app in Windows in KVM works.
 usb 4-2.2: check_ctrlrecip: process 13073 (qemu-kvm) requesting ep 01 but needs 81

I suspect this will mostly affect apps in virtual environments; as on
Linux the apps would have been adapted to the stricter handling of the
kernel. I have done that for mine[2].

[1] http://www.pegatech.com/
[2] https://sourceforge.net/projects/notetakerpen/

Signed-off-by: Kurt Garloff 
Acked-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

usbfs: Always allow ctrl requests with USB_RECIP_ENDPOINT on the ctrl ep

2013-05-13T14:02:20+00:00

commit 1361bf4b9f9ef45e628a5b89e0fd9bedfdcb7104 upstream.

When usbfs receives a ctrl-request from userspace it calls check_ctrlrecip,
which for a request with USB_RECIP_ENDPOINT tries to map this to an interface
to see if this interface is claimed, except for ctrl-requests with a type of
USB_TYPE_VENDOR.

When trying to use this device: http://www.akaipro.com/eiepro
redirected to a Windows vm running on qemu on top of Linux.

The windows driver makes a ctrl-req with USB_TYPE_CLASS and
USB_RECIP_ENDPOINT with index 0, and the mapping of the endpoint (0) to
the interface fails since ep 0 is the ctrl endpoint and thus never is
part of an interface.

This patch fixes this ctrl-req failing by skipping the checkintf call for
USB_RECIP_ENDPOINT ctrl-reqs on the ctrl endpoint.

Reported-by: Dave Stikkolorum 
Tested-by: Dave Stikkolorum 
Signed-off-by: Hans de Goede 
Acked-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

usbdevfs: Correct amount of data copied to user in processcompl_compat

2012-08-02T13:37:45+00:00

commit 2102e06a5f2e414694921f23591f072a5ba7db9f upstream.

iso data buffers may have holes in them if some packets were short, so for
iso urbs we should always copy the entire buffer, just like the regular
processcompl does.

Signed-off-by: Hans de Goede 
Acked-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings