CCGx controller used on NVIDIA GPU card has two separate display
altmode for two DP pin assignments. UCSI specification doesn't
prohibits using separate display altmode.
Current UCSI Type-C framework expects only one display altmode for
all DP pin assignment. This patch squashes two separate display
altmode into single altmode to support controllers with separate
display altmode. We first read all the alternate modes of connector
and then run through it to know if there are separate display
altmodes. If so, it prepares a new port altmode set after squashing
two or more separate altmodes into one.
Signed-off-by: Ajay Gupta <ajayg@nvidia.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20191230133431.63445-3-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver needs to ignore any Connector Change Events
before the Connector Change Indication notifications have
actually been enabled. This adds a check to
ucsi_connector_change() function to make sure the function
does not try to process the event unless the Connector
Change notifications have been enabled.
It is quite common that the firmware representing the "PPM"
(Platform Policy Manager) starts generating Connector Change
notifications even when only the Command Completion
notifications are enabled.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20191230133431.63445-2-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The mtk-xhci platform glue sets the DMA mask to 32 bits on its own,
which was needed before commit fda182d80a ("usb: xhci: configure
32-bit DMA if the controller does not support 64-bit DMA"), but now it
has no effect, because xhci_gen_setup() sets it up for us according to
hardware capabilities. Remove the useless code.
Signed-off-by: Tomasz Figa <tfiga@chromium.org>
Link: https://lore.kernel.org/r/20191219093954.163417-1-tfiga@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
AB8505 supports an "UART carkit mode" which makes UART accessible
through the USB connector. Upon detection of the UART cable,
this mode has to be manually enabled by:
1. Turning on the PHY in peripheral mode
2. Reconfiguring PHY/pins to route UART signals to USB pins
At the moment, we do not handle the UART link statuses at all,
which means that UART stops working as soon as phy-ab8500-usb is loaded
(since we disable the PHY after initialization).
Keeping UART working if the cable is inserted before turning on the device
is quite simple: In this case, early boot firmware has already set up
the necessary PHY/pin configuration. The presence of the UART cable
is reported by a special value in the USB link status register.
We can check for that value in ab8505_usb_link_status_update()
and set the PHY back to peripheral mode to restore UART.
(Note: This will result in some minor garbage since we still
temporarily disable the PHY during initialization...)
Fully implementing this feature is more complicated:
For some reason, AB8505 does not update UART link status after bootup.
Regular USB cables work fine, but the link status register does not change
its state if an UART cable is inserted/removed.
It seems likely that the hardware is not actually capable of detecting
UART cables autonomously. In addition to the USB link status register,
implementations in the vendor kernel also manually measure
the ID resistance to detect additional cable types. For UART cables,
the USB link status register might simply reflect the PHY configuration
instead of the actual link status.
Implementing that functionality requires significant additions,
so for now just implement the simple case. This allows using UART
when inserting the cable before turning on the device.
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20191218203450.71037-1-stephan@gerhold.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On shutdown, ehci_power_off() is called unconditionally to power off
each port, even if it was never called to power on the port.
For chipidea, this results in a call to ehci_ci_portpower() with a request
to power off ports even if the port was never powered on.
This results in the following warning from the regulator code.
WARNING: CPU: 0 PID: 182 at drivers/regulator/core.c:2596 _regulator_disable+0x1a8/0x210
unbalanced disables for usb_otg2_vbus
Modules linked in:
CPU: 0 PID: 182 Comm: init Not tainted 5.4.6 #1
Hardware name: Freescale i.MX7 Dual (Device Tree)
[<c0313658>] (unwind_backtrace) from [<c030d698>] (show_stack+0x10/0x14)
[<c030d698>] (show_stack) from [<c1133afc>] (dump_stack+0xe0/0x10c)
[<c1133afc>] (dump_stack) from [<c0349098>] (__warn+0xf4/0x10c)
[<c0349098>] (__warn) from [<c0349128>] (warn_slowpath_fmt+0x78/0xbc)
[<c0349128>] (warn_slowpath_fmt) from [<c09f36ac>] (_regulator_disable+0x1a8/0x210)
[<c09f36ac>] (_regulator_disable) from [<c09f374c>] (regulator_disable+0x38/0xe8)
[<c09f374c>] (regulator_disable) from [<c0df7bac>] (ehci_ci_portpower+0x38/0xdc)
[<c0df7bac>] (ehci_ci_portpower) from [<c0db4fa4>] (ehci_port_power+0x50/0xa4)
[<c0db4fa4>] (ehci_port_power) from [<c0db5420>] (ehci_silence_controller+0x5c/0xc4)
[<c0db5420>] (ehci_silence_controller) from [<c0db7644>] (ehci_stop+0x3c/0xcc)
[<c0db7644>] (ehci_stop) from [<c0d5bdc4>] (usb_remove_hcd+0xe0/0x19c)
[<c0d5bdc4>] (usb_remove_hcd) from [<c0df7638>] (host_stop+0x38/0xa8)
[<c0df7638>] (host_stop) from [<c0df2f34>] (ci_hdrc_remove+0x44/0xe4)
...
Keeping track of the power enable state avoids the warning and traceback.
Fixes: c8679a2fb8 ("usb: chipidea: host: add portpower override")
Cc: Michael Grzeschik <m.grzeschik@pengutronix.de>
Cc: Peter Chen <peter.chen@freescale.com>
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Peter Chen <peter.chen@nxp.com>
Link: https://lore.kernel.org/r/20191226155754.25451-1-linux@roeck-us.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Without this, this new driver fails to link:
drivers/usb/gadget/udc/tegra-xudc.o: In function `tegra_xudc_remove':
tegra-xudc.c:(.text+0x19d4): undefined reference to `usb_role_switch_unregister'
drivers/usb/gadget/udc/tegra-xudc.o: In function `tegra_xudc_probe':
tegra-xudc.c:(.text+0x2a34): undefined reference to `usb_role_switch_register'
drivers/usb/gadget/udc/tegra-xudc.o: In function `tegra_xudc_usb_role_sw_work':
tegra-xudc.c:(.text+0x4b64): undefined reference to `usb_role_switch_get_role'
Fixes: 49db427232 ("usb: gadget: Add UDC driver for tegra XUSB device mode controller")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20191216131831.3228566-1-arnd@arndb.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Amend the endpoint-descriptor sanity checks to detect all duplicate
endpoint addresses in a configuration.
Commit 0a8fd13462 ("USB: fix problems with duplicate endpoint
addresses") added a check for duplicate endpoint addresses within a
single alternate setting, but did not look for duplicate addresses in
other interfaces.
The current check would also not detect all duplicate addresses when one
endpoint is as a (bi-directional) control endpoint.
This specifically avoids overwriting the endpoint entries in struct
usb_device when enabling a duplicate endpoint, something which could
potentially lead to crashes or leaks, for example, when endpoints are
later disabled.
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20191219161016.6695-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Telit FN980 flashing device 0x1bc7/0x9010 requires zero packet
to be sent if out data size is is equal to the endpoint max size.
Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
[ johan: switch operands in conditional ]
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
If a transaction error happens in vhci_recv_ret_submit(), event
handler closes connection and changes port status to kick hub_event.
Then hub tries to flush the endpoint URBs, but that causes infinite
loop between usb_hub_flush_endpoint() and vhci_urb_dequeue() because
"vhci_priv" in vhci_urb_dequeue() was already released by
vhci_recv_ret_submit() before a transmission error occurred. Thus,
vhci_urb_dequeue() terminates early and usb_hub_flush_endpoint()
continuously calls vhci_urb_dequeue().
The root cause of this issue is that vhci_recv_ret_submit()
terminates early without giving back URB when transaction error
occurs in vhci_recv_ret_submit(). That causes the error URB to still
be linked at endpoint list without “vhci_priv".
So, in the case of transaction error in vhci_recv_ret_submit(),
unlink URB from the endpoint, insert proper error code in
urb->status and give back URB.
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Suwan Kim <suwan.kim027@gmail.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20191213023055.19933-3-suwan.kim027@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/gadget/Kconfig includes drivers/usb/gadget/legacy/Kconfig
inside the 'choice' block. The current Kconfig allows this, but I'd
like to discourage this usage.
People tend to mess up the structure without noticing that entire
drivers/usb/gadget/legacy/Kconfig is placed in the choice context.
In fact, legacy/Kconfig mixes up bool and tristate in the choice,
and creates nested choice, etc.
This commit does not change the behavior, but it will help people
notice how badly this Kconfig file is written.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20191211073857.16780-1-masahiroy@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When disconnecting a USB hub that has some child device(s) connected to it
(such as a USB mouse), then the stack tries to clear halt and
reset device(s) which are _already_ physically disconnected.
The issue has been reproduced with:
CPU: IMX6D5EYM10AD or MCIMX6D5EYM10AE.
SW: U-Boot 2019.07 and kernel 4.19.40.
CPU: HP Proliant Microserver Gen8.
SW: Linux version 4.2.3-300.fc23.x86_64
In this situation there will be error bit for MMF active yet the
CERR equals EHCI_TUNE_CERR + halt. Existing implementation
interprets this as a stall [1] (chapter 8.4.5).
The possible conditions when the MMF will be active + halt
can be found from [2] (Table 4-13).
Fix for the issue is to check whether MMF is active and PID Code is
IN before checking for the stall. If these conditions are true then
it is not a stall.
What happens after the fix is that when disconnecting a hub with
attached device(s) the situation is not interpret as a stall.
[1] [https://www.usb.org/document-library/usb-20-specification, usb_20.pdf]
[2] [https://www.intel.com/content/dam/www/public/us/en/documents/
technical-specifications/ehci-specification-for-usb.pdf]
Signed-off-by: Erkka Talvitie <erkka.talvitie@vincit.fi>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/ef70941d5f349767f19c0ed26b0dd9eed8ad81bb.1576050523.git.erkka.talvitie@vincit.fi
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes the following compile error:
drivers/usb/typec/tcpm/fusb302.o: In function `tcpm_get_current_limit':
fusb302.c:(.text+0x3ee): undefined reference to `extcon_get_state'
fusb302.c:(.text+0x422): undefined reference to `extcon_get_state'
fusb302.c:(.text+0x450): undefined reference to `extcon_get_state'
fusb302.c:(.text+0x48c): undefined reference to `extcon_get_state'
drivers/usb/typec/tcpm/fusb302.o: In function `fusb302_probe':
fusb302.c:(.text+0x980): undefined reference to `extcon_get_extcon_dev'
make: *** [vmlinux] Error 1
It is because EXTCON is build as a module, but FUSB302 is not.
Suggested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/1576239378-50795-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull USB fixes from Greg KH:
"Here are some small USB driver fixes for reported issues for 5.5-rc2
There's the usual gadget and xhci fixes, as well as some other
problems that syzbot has been finding during it's fuzzing runs. Full
details are in the shortlog.
All of these have been in linux-next with no reported issues"
* tag 'usb-5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (21 commits)
usb: dwc3: pci: add ID for the Intel Comet Lake -H variant
xhci: make sure interrupts are restored to correct state
xhci: handle some XHCI_TRUST_TX_LENGTH quirks cases as default behaviour.
xhci: Increase STS_HALT timeout in xhci_suspend()
usb: xhci: only set D3hot for pci device
xhci: fix USB3 device initiated resume race with roothub autosuspend
xhci: Fix memory leak in xhci_add_in_port()
USB: Fix incorrect DMA allocations for local memory pool drivers
usb: gadget: fix wrong endpoint desc
usb: dwc3: ep0: Clear started flag on completion
usb: dwc3: gadget: Clear started flag for non-IOC
usb: dwc3: gadget: Fix logical condition
USB: atm: ueagle-atm: add missing endpoint check
USB: adutux: fix interface sanity check
USB: idmouse: fix interface sanity checks
USB: serial: io_edgeport: fix epic endpoint lookup
usb: mon: Fix a deadlock in usbmon between mmap and read
usb: common: usb-conn-gpio: Don't log an error on probe deferral
usb: core: urb: fix URB structure initialization function
usb: typec: fix use after free in typec_register_port()
...
spin_unlock_irqrestore() might be called with stale flags after
reading port status, possibly restoring interrupts to a incorrect
state.
If a usb2 port just finished resuming while the port status is read
the spin lock will be temporary released and re-acquired in a separate
function. The flags parameter is passed as value instead of a pointer,
not updating flags properly before the final spin_unlock_irqrestore()
is called.
Cc: <stable@vger.kernel.org> # v3.12+
Fixes: 8b3d45705e ("usb: Fix xHCI host issues on remote wakeup.")
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20191211142007.8847-7-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xhci driver claims it needs XHCI_TRUST_TX_LENGTH quirk for both
Broadcom/Cavium and a Renesas xHC controllers.
The quirk was inteded for handling false "success" complete event for
transfers that had data left untransferred.
These transfers should complete with "short packet" events instead.
In these two new cases the false "success" completion is reported
after a "short packet" if the TD consists of several TRBs.
xHCI specs 4.10.1.1.2 say remaining TRBs should report "short packet"
as well after the first short packet in a TD, but this issue seems so
common it doesn't make sense to add the quirk for all vendors.
Turn these events into short packets automatically instead.
This gets rid of the "The WARN Successful completion on short TX for
slot 1 ep 1: needs XHCI_TRUST_TX_LENGTH quirk" warning in many cases.
Cc: <stable@vger.kernel.org>
Reported-by: Eli Billauer <eli.billauer@gmail.com>
Reported-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Eli Billauer <eli.billauer@gmail.com>
Tested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20191211142007.8847-6-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A race in xhci USB3 remote wake handling may force device back to suspend
after it initiated resume siganaling, causing a missed resume event or warm
reset of device.
When a USB3 link completes resume signaling and goes to enabled (UO)
state a interrupt is issued and the interrupt handler will clear the
bus_state->port_remote_wakeup resume flag, allowing bus suspend.
If the USB3 roothub thread just finished reading port status before
the interrupt, finding ports still in suspended (U3) state, but hasn't
yet started suspending the hub, then the xhci interrupt handler will clear
the flag that prevented roothub suspend and allow bus to suspend, forcing
all port links back to suspended (U3) state.
Example case:
usb_runtime_suspend() # because all ports still show suspended U3
usb_suspend_both()
hub_suspend(); # successful as hub->wakeup_bits not set yet
==> INTERRUPT
xhci_irq()
handle_port_status()
clear bus_state->port_remote_wakeup
usb_wakeup_notification()
sets hub->wakeup_bits;
kick_hub_wq()
<== END INTERRUPT
hcd_bus_suspend()
xhci_bus_suspend() # success as port_remote_wakeup bits cleared
Fix this by increasing roothub usage count during port resume to prevent
roothub autosuspend, and by making sure bus_state->port_remote_wakeup
flag is only cleared after resume completion is visible, i.e.
after xhci roothub returned U0 or other non-U3 link state link on a
get port status request.
Issue rootcaused by Chiasheng Lee
Cc: <stable@vger.kernel.org>
Cc: Lee, Hou-hsun <hou-hsun.lee@intel.com>
Reported-by: Lee, Chiasheng <chiasheng.lee@intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20191211142007.8847-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Felipe writes:
USB: fixes for v5.5-rc2
Only four patches here this time around. Three of them are on dwc3
fixing some small bugs related to our 'started' flag.
None are major fixes but they're important nevertheless.
* tag 'fixes-for-v5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb:
usb: gadget: fix wrong endpoint desc
usb: dwc3: ep0: Clear started flag on completion
usb: dwc3: gadget: Clear started flag for non-IOC
usb: dwc3: gadget: Fix logical condition
Fix commit 7b81cb6bdd ("usb: add a HCD_DMA flag instead of
guestimating DMA capabilities") where local memory USB drivers
erroneously allocate DMA memory instead of pool memory, causing
OHCI Unrecoverable Error, disabled
HC died; cleaning up
The order between hcd_uses_dma() and hcd->localmem_pool is now
arranged as in hcd_buffer_alloc() and hcd_buffer_free(), with the
test for hcd->localmem_pool placed first.
As an alternative, one might consider adjusting hcd_uses_dma() with
static inline bool hcd_uses_dma(struct usb_hcd *hcd)
{
- return IS_ENABLED(CONFIG_HAS_DMA) && (hcd->driver->flags & HCD_DMA);
+ return IS_ENABLED(CONFIG_HAS_DMA) &&
+ (hcd->driver->flags & HCD_DMA) &&
+ (hcd->localmem_pool == NULL);
}
One can also consider unsetting HCD_DMA for local memory pool drivers.
Fixes: 7b81cb6bdd ("usb: add a HCD_DMA flag instead of guestimating DMA capabilities")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Fredrik Noring <noring@nocrew.org>
Link: https://lore.kernel.org/r/20191210172905.GA52526@sx9
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Gadget driver should always use config_ep_by_speed() to initialize
usb_ep struct according to usb device's operating speed. Otherwise,
usb_ep struct may be wrong if usb devcie's operating speed is changed.
The key point in this patch is that we want to make sure the desc pointer
in usb_ep struct will be set to NULL when gadget is disconnected.
This will force it to call config_ep_by_speed() to correctly initialize
usb_ep struct based on the new operating speed when gadget is
re-connected later.
Reviewed-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: EJ Hsu <ejh@nvidia.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Clear ep0's DWC3_EP_TRANSFER_STARTED flag if the END_TRANSFER command is
completed. Otherwise, we can't start control transfer again after
END_TRANSFER.
Cc: stable@vger.kernel.org
Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Normally the END_TRANSFER command completion handler will clear the
DWC3_EP_TRANSFER_STARTED flag. However, if the command was sent without
interrupt on completion, then the flag will not be cleared. Make sure to
clear the flag in this case.
Cc: stable@vger.kernel.org
Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
This patch corrects the condition to kick the transfer without
giving back the requests when either request has remaining data
or when there are pending SGs. The && check was introduced during
spliting up the dwc3_gadget_ep_cleanup_completed_requests() function.
Fixes: f38e35dd84 ("usb: dwc3: gadget: split dwc3_gadget_ep_cleanup_completed_requests()")
Cc: stable@vger.kernel.org
Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Make sure that the interrupt interface has an endpoint before trying to
access its endpoint descriptors to avoid dereferencing a NULL pointer.
The driver binds to the interrupt interface with interface number 0, but
must not assume that this interface or its current alternate setting are
the first entries in the corresponding configuration arrays.
Fixes: b72458a80c ("[PATCH] USB: Eagle and ADI 930 usb adsl modem driver")
Cc: stable <stable@vger.kernel.org> # 2.6.16
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191210112601.3561-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make sure to use the current alternate setting when verifying the
interface descriptors to avoid binding to an invalid interface.
Failing to do so could cause the driver to misbehave or trigger a WARN()
in usb_submit_urb() that kernels with panic_on_warn set would choke on.
Fixes: 03270634e2 ("USB: Add ADU support for Ontrak ADU devices")
Cc: stable <stable@vger.kernel.org> # 2.6.19
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191210112601.3561-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make sure to use the current alternate setting when looking up the
endpoints on epic devices to avoid binding to an invalid interface.
Failing to do so could cause the driver to misbehave or trigger a WARN()
in usb_submit_urb() that kernels with panic_on_warn set would choke on.
Fixes: 6e8cf7751f ("USB: add EPIC support to the io_edgeport driver")
Cc: stable <stable@vger.kernel.org> # 2.6.21
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191210112601.3561-5-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The problem arises because our read() function grabs a lock of the
circular buffer, finds something of interest, then invokes copy_to_user()
straight from the buffer, which in turn takes mm->mmap_sem. In the same
time, the callback mon_bin_vma_fault() is invoked under mm->mmap_sem.
It attempts to take the fetch lock and deadlocks.
This patch does away with protecting of our page list with any
semaphores, and instead relies on the kernel not close the device
while mmap is active in a process.
In addition, we prohibit re-sizing of a buffer while mmap is active.
This way, when (now unlocked) fault is processed, it works with the
page that is intended to be mapped-in, and not some other random page.
Note that this may have an ABI impact, but hopefully no legitimate
program is this wrong.
Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Reported-by: syzbot+56f9673bb4cdcbeb0e92@syzkaller.appspotmail.com
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Fixes: 46eb14a6e1 ("USB: fix usbmon BUG trigger")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191204203941.3503452b@suzdal.zaitcev.lan
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
