commit 26fbe9772b upstream.
The syzbot fuzzer has identified a bug in which processes hang waiting
for usb_kill_urb() to return. It turns out the issue is not unlinking
the URB; that works just fine. Rather, the problem arises when the
wakeup notification that the URB has completed is not received.
The reason is memory-access ordering on SMP systems. In outline form,
usb_kill_urb() and __usb_hcd_giveback_urb() operating concurrently on
different CPUs perform the following actions:
CPU 0 CPU 1
---------------------------- ---------------------------------
usb_kill_urb(): __usb_hcd_giveback_urb():
... ...
atomic_inc(&urb->reject); atomic_dec(&urb->use_count);
... ...
wait_event(usb_kill_urb_queue,
atomic_read(&urb->use_count) == 0);
if (atomic_read(&urb->reject))
wake_up(&usb_kill_urb_queue);
Confining your attention to urb->reject and urb->use_count, you can
see that the overall pattern of accesses on CPU 0 is:
write urb->reject, then read urb->use_count;
whereas the overall pattern of accesses on CPU 1 is:
write urb->use_count, then read urb->reject.
This pattern is referred to in memory-model circles as SB (for "Store
Buffering"), and it is well known that without suitable enforcement of
the desired order of accesses -- in the form of memory barriers -- it
is entirely possible for one or both CPUs to execute their reads ahead
of their writes. The end result will be that sometimes CPU 0 sees the
old un-decremented value of urb->use_count while CPU 1 sees the old
un-incremented value of urb->reject. Consequently CPU 0 ends up on
the wait queue and never gets woken up, leading to the observed hang
in usb_kill_urb().
The same pattern of accesses occurs in usb_poison_urb() and the
failure pathway of usb_hcd_submit_urb().
The problem is fixed by adding suitable memory barriers. To provide
proper memory-access ordering in the SB pattern, a full barrier is
required on both CPUs. The atomic_inc() and atomic_dec() accesses
themselves don't provide any memory ordering, but since they are
present, we can use the optimized smp_mb__after_atomic() memory
barrier in the various routines to obtain the desired effect.
This patch adds the necessary memory barriers.
CC: <stable@vger.kernel.org>
Reported-and-tested-by: syzbot+76629376e06e2c2ad626@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/Ye8K0QYee0Q0Nna2@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0055858638 ]
When a new USB device gets plugged to nested hubs, the affected hub,
which connects to usb 2-1.4-port2, doesn't report there's any change,
hence the nested hubs go back to runtime suspend like nothing happened:
[ 281.032951] usb usb2: usb wakeup-resume
[ 281.032959] usb usb2: usb auto-resume
[ 281.032974] hub 2-0:1.0: hub_resume
[ 281.033011] usb usb2-port1: status 0263 change 0000
[ 281.033077] hub 2-0:1.0: state 7 ports 4 chg 0000 evt 0000
[ 281.049797] usb 2-1: usb wakeup-resume
[ 281.069800] usb 2-1: Waited 0ms for CONNECT
[ 281.069810] usb 2-1: finish resume
[ 281.070026] hub 2-1:1.0: hub_resume
[ 281.070250] usb 2-1-port4: status 0203 change 0000
[ 281.070272] usb usb2-port1: resume, status 0
[ 281.070282] hub 2-1:1.0: state 7 ports 4 chg 0010 evt 0000
[ 281.089813] usb 2-1.4: usb wakeup-resume
[ 281.109792] usb 2-1.4: Waited 0ms for CONNECT
[ 281.109801] usb 2-1.4: finish resume
[ 281.109991] hub 2-1.4:1.0: hub_resume
[ 281.110147] usb 2-1.4-port2: status 0263 change 0000
[ 281.110234] usb 2-1-port4: resume, status 0
[ 281.110239] usb 2-1-port4: status 0203, change 0000, 10.0 Gb/s
[ 281.110266] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000
[ 281.110426] hub 2-1.4:1.0: hub_suspend
[ 281.110565] usb 2-1.4: usb auto-suspend, wakeup 1
[ 281.130998] hub 2-1:1.0: hub_suspend
[ 281.137788] usb 2-1: usb auto-suspend, wakeup 1
[ 281.142935] hub 2-0:1.0: state 7 ports 4 chg 0000 evt 0000
[ 281.177828] usb 2-1: usb wakeup-resume
[ 281.197839] usb 2-1: Waited 0ms for CONNECT
[ 281.197850] usb 2-1: finish resume
[ 281.197984] hub 2-1:1.0: hub_resume
[ 281.198203] usb 2-1-port4: status 0203 change 0000
[ 281.198228] usb usb2-port1: resume, status 0
[ 281.198237] hub 2-1:1.0: state 7 ports 4 chg 0010 evt 0000
[ 281.217835] usb 2-1.4: usb wakeup-resume
[ 281.237834] usb 2-1.4: Waited 0ms for CONNECT
[ 281.237845] usb 2-1.4: finish resume
[ 281.237990] hub 2-1.4:1.0: hub_resume
[ 281.238067] usb 2-1.4-port2: status 0263 change 0000
[ 281.238148] usb 2-1-port4: resume, status 0
[ 281.238152] usb 2-1-port4: status 0203, change 0000, 10.0 Gb/s
[ 281.238166] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000
[ 281.238385] hub 2-1.4:1.0: hub_suspend
[ 281.238523] usb 2-1.4: usb auto-suspend, wakeup 1
[ 281.258076] hub 2-1:1.0: hub_suspend
[ 281.265744] usb 2-1: usb auto-suspend, wakeup 1
[ 281.285976] hub 2-0:1.0: hub_suspend
[ 281.285988] usb usb2: bus auto-suspend, wakeup 1
USB 3.2 spec, 9.2.5.4 "Changing Function Suspend State" says that "If
the link is in a non-U0 state, then the device must transition the link
to U0 prior to sending the remote wake message", but the hub only
transits the link to U0 after signaling remote wakeup.
So be more forgiving and use a 20ms delay to let the link transit to U0
for remote wakeup.
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Link: https://lore.kernel.org/r/20211215120108.336597-1-kai.heng.feng@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 1d7d4c0793 upstream.
When the USB core code for getting root-hub status reports was
originally written, it was assumed that the hub driver would be its
only caller. But this isn't true now; user programs can use usbfs to
communicate with root hubs and get status reports. When they do this,
they may use a transfer_buffer that is smaller than the data returned
by the HCD, which will lead to a buffer overflow error when
usb_hcd_poll_rh_status() tries to store the status data. This was
discovered by syzbot:
BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline]
BUG: KASAN: slab-out-of-bounds in usb_hcd_poll_rh_status+0x5f4/0x780 drivers/usb/core/hcd.c:776
Write of size 2 at addr ffff88801da403c0 by task syz-executor133/4062
This patch fixes the bug by reducing the amount of status data if it
won't fit in the transfer_buffer. If some data gets discarded then
the URB's completion status is set to -EOVERFLOW rather than 0, to let
the user know what happened.
Reported-and-tested-by: syzbot+3ae6a2b06f131ab9849f@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/Yc+3UIQJ2STbxNua@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0f663729bb upstream.
Bugzilla #213839 reports a 7-port hub that doesn't work properly when
devices are plugged into some of the ports; the kernel goes into an
unending disconnect/reinitialize loop as shown in the bug report.
This "7-port hub" comprises two four-port hubs with one plugged into
the other; the failures occur when a device is plugged into one of the
downstream hub's ports. (These hubs have other problems too. For
example, they bill themselves as USB-2.0 compliant but they only run
at full speed.)
It turns out that the failures are caused by bugs in both the kernel
and the hub. The hub's bug is that it reports a different
bmAttributes value in its configuration descriptor following a remote
wakeup (0xe0 before, 0xc0 after -- the wakeup-support bit has
changed).
The kernel's bug is inside the hub driver's resume handler. When
hub_activate() sees that one of the hub's downstream ports got a
wakeup request from a child device, it notes this fact by setting the
corresponding bit in the hub->change_bits variable. But this variable
is meant for connection changes, not wakeup events; setting it causes
the driver to believe the downstream port has been disconnected and
then connected again (in addition to having received a wakeup
request).
Because of this, the hub driver then tries to check whether the device
currently plugged into the downstream port is the same as the device
that had been attached there before. Normally this check succeeds and
wakeup handling continues with no harm done (which is why the bug
remained undetected until now). But with these dodgy hubs, the check
fails because the config descriptor has changed. This causes the hub
driver to reinitialize the child device, leading to the
disconnect/reinitialize loop described in the bug report.
The proper way to note reception of a downstream wakeup request is
to set a bit in the hub->event_bits variable instead of
hub->change_bits. That way the hub driver will realize that something
has happened to the port but will not think the port and child device
have been disconnected. This patch makes that change.
Cc: <stable@vger.kernel.org>
Tested-by: Jonathan McDowell <noodles@earth.li>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/YdCw7nSfWYPKWQoD@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6ae6dc22d2 upstream.
xHC hardware can only have one slot in default state with address 0
waiting for a unique address at a time, otherwise "undefined behavior
may occur" according to xhci spec 5.4.3.4
The address0_mutex exists to prevent this across both xhci roothubs.
If hub_port_init() fails, it may unlock the mutex and exit with a xhci
slot in default state. If the other xhci roothub calls hub_port_init()
at this point we end up with two slots in default state.
Make sure the address0_mutex protects the slot default state across
hub_port_init() retries, until slot is addressed or disabled.
Note, one known minor case is not fixed by this patch.
If device needs to be reset during resume, but fails all hub_port_init()
retries in usb_reset_and_verify_device(), then it's possible the slot is
still left in default state when address0_mutex is unlocked.
Cc: <stable@vger.kernel.org>
Fixes: 638139eb95 ("usb: hub: allow to process more usb hub events in parallel")
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20211115221630.871204-1-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 58877b0824 upstream.
It has been observed with certain PCIe USB cards (like Inateck connected
to AM64 EVM or J7200 EVM) that as soon as the primary roothub is
registered, port status change is handled even before xHC is running
leading to cold plug USB devices not detected. For such cases, registering
both the root hubs along with the second HCD is required. Add support for
deferring roothub registration in usb_add_hcd(), so that both primary and
secondary roothubs are registered along with the second HCD.
CC: stable@vger.kernel.org # 5.4+
Suggested-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Tested-by: Chris Chiu <chris.chiu@canonical.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Link: https://lore.kernel.org/r/20210909064200.16216-2-kishon@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b0863f1927 ]
When the user submits a control URB via usbfs, the user supplies the
bRequestType value and the kernel uses it to compute the pipe value.
However, do_proc_control() performs this computation incorrectly in
the case where the bRequestType direction bit is set to USB_DIR_IN and
the URB's transfer length is 0: The pipe's direction is also set to IN
but it should be OUT, which is the direction the actual transfer will
use regardless of bRequestType.
Commit 5cc59c418f ("USB: core: WARN if pipe direction != setup
packet direction") added a check to compare the direction bit in the
pipe value to a control URB's actual direction and to WARN if they are
different. This can be triggered by the incorrect computation
mentioned above, as found by syzbot.
This patch fixes the computation, thus avoiding the WARNing.
Reported-and-tested-by: syzbot+72af3105289dcb4c055b@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20210712185436.GB326369@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 1bf2761c83 upstream.
Maximum Exit Latency (MEL) value is used by host to know how much in
advance it needs to start waking up a U1/U2 suspended link in order to
service a periodic transfer in time.
Current MEL calculation only includes the time to wake up the path from
U1/U2 to U0. This is called tMEL1 in USB 3.1 section C 1.5.2
Total MEL = tMEL1 + tMEL2 +tMEL3 + tMEL4 which should additinally include:
- tMEL2 which is the time it takes for PING message to reach device
- tMEL3 time for device to process the PING and submit a PING_RESPONSE
- tMEL4 time for PING_RESPONSE to traverse back upstream to host.
Add the missing tMEL2, tMEL3 and tMEL4 to MEL calculation.
Cc: <stable@kernel.org> # v3.5
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210715150122.1995966-1-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1b7f56fbc7 upstream.
The device initiated link power management U1/U2 states should not be
enabled in case the system exit latency plus one bus interval (125us) is
greater than the shortest service interval of any periodic endpoint.
This is the case for both U1 and U2 sytstem exit latencies and link states.
See USB 3.2 section 9.4.9 "Set Feature" for more details
Note, before this patch the host and device initiated U1/U2 lpm states
were both enabled with lpm. After this patch it's possible to end up with
only host inititated U1/U2 lpm in case the exit latencies won't allow
device initiated lpm.
If this case we still want to set the udev->usb3_lpm_ux_enabled flag so
that sysfs users can see the link may go to U1/U2.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210715150122.1995966-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f3a1a937f7 ]
This reverts commit 0bd860493f.
While the patch was working as stated,ie preventing the L850-GL LTE modem
from crashing on some U3 wake-ups due to a race condition between the
host wake-up and the modem-side wake-up, when using the MBIM interface,
this would force disabling the USB runtime PM on the device.
The increased power consumption is significant for LTE laptops,
and given that with decently recent modem firmwares, when the modem hits
the bug, it automatically recovers (ie it drops from the bus, but
automatically re-enumerates after less than half a second, rather than being
stuck until a power cycle as it was doing with ancient firmware), for
most people, the trade-off now seems in favor of re-enabling it by
default.
For people with access to the platform code, the bug can also be worked-around
successfully by changing the USB3 LFPM polling off-time for the XHCI
controller in the BIOS code.
Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Link: https://lore.kernel.org/r/20210721092516.2775971-1-vpalatin@chromium.org
Fixes: 0bd860493f ("USB: quirks: ignore remote wake-up on Fibocom L850-GL LTE modem")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit a7d8d1c7a7 upstream.
The Cypress CY7C65632 appears to have an issue with auto suspend and
detecting devices, not too dissimilar to the SMSC 5534B hub. It is
easiest to reproduce by connecting multiple mass storage devices to
the hub at the same time. On a Lenovo Yoga, around 1 in 3 attempts
result in the devices not being detected. It is however possible to
make them appear using lsusb -v.
Disabling autosuspend for this hub resolves the issue.
Fixes: 1208f9e1d7 ("USB: hub: Fix the broken detection of USB3 device in SMSC hub")
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20210614155524.2228800-1-andrew@lunn.ch
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ca91fd8c76 upstream.
Realtek Hub (0bda:5487) in Dell Dock WD19 sometimes fails to work
after the system resumes from suspend with remote wakeup enabled
device connected:
[ 1947.640907] hub 5-2.3:1.0: hub_ext_port_status failed (err = -71)
[ 1947.641208] usb 5-2.3-port5: cannot disable (err = -71)
[ 1947.641401] hub 5-2.3:1.0: hub_ext_port_status failed (err = -71)
[ 1947.641450] usb 5-2.3-port4: cannot reset (err = -71)
Information of this hub:
T: Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 10 Spd=480 MxCh= 5
D: Ver= 2.10 Cls=09(hub ) Sub=00 Prot=02 MxPS=64 #Cfgs= 1
P: Vendor=0bda ProdID=5487 Rev= 1.47
S: Manufacturer=Dell Inc.
S: Product=Dell dock
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mA
I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=01 Driver=hub
E: Ad=81(I) Atr=03(Int.) MxPS= 1 Ivl=256ms
I:* If#= 0 Alt= 1 #EPs= 1 Cls=09(hub ) Sub=00 Prot=02 Driver=hub
E: Ad=81(I) Atr=03(Int.) MxPS= 1 Ivl=256ms
The failure results from the ETIMEDOUT by chance when turning on
the suspend feature for the specified port of the hub. The port
seems to be in an unknown state so the hub_activate during resume
fails the hub_port_status, then the hub will fail to work.
The quirky hub needs the reset-resume quirk to function correctly.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Chris Chiu <chris.chiu@canonical.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210420174651.6202-1-chris.chiu@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
