[ Upstream commit ce7d0008c2356626f69f37ef1afce8fbc83fe142 ]
Some UDCs may have constraints on how many high bandwidth endpoints it can
support in a certain configuration. This API allows for the composite
driver to pass down the total number of endpoints to the UDC so it can verify
it has the required resources to support the configuration.
Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Link: https://lore.kernel.org/r/1625908395-5498-2-git-send-email-wcheng@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: dbe678f6192f ("usb: cdns3: fix NCM gadget RX speed 20x slow than expection at iMX8QM")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit a8291be6b5dd465c22af229483dbac543a91e24e upstream.
This reverts commit f08aa7c80dac27ee00fa6827f447597d2fba5465.
The reverted commit was based on static analysis and a misunderstanding
of how PTR_ERR() and NULLs are supposed to work. When a function
returns both pointer errors and NULL then normally the NULL means
"continue operating without a feature because it was deliberately
turned off". The NULL should not be treated as a failure. If a driver
cannot work when that feature is disabled then the KConfig should
enforce that the function cannot return NULL. We should not need to
test for it.
In this driver, the bug means that probe cannot succeed when CONFIG_PM
is disabled.
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: f08aa7c80dac ("usb: gadget: tegra-xudc: Fix error check in tegra_xudc_powerdomain_init()")
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/ZKQoBa84U/ykEh3C@moroto
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 5629d31955297ca47b9283c64fff70f2f34aa528 ]
Commit ac82b56bda ("usb: gadget: tegra-xudc: Add vbus_draw support")
populated the vbus_draw callback for the Tegra XUDC driver. The function
tegra_xudc_gadget_vbus_draw(), that was added by this commit, assumes
that the pointer 'curr_usbphy' has been initialised, which is not always
the case because this is only initialised when the USB role is updated.
Fix this crash, by checking that the 'curr_usbphy' is valid before
dereferencing.
Fixes: ac82b56bda ("usb: gadget: tegra-xudc: Add vbus_draw support")
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20230405181854.42355-1-jonathanh@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2b947f8769be8b8181dc795fd292d3e7120f5204 ]
In renesas_usb3_probe, role_work is bound with renesas_usb3_role_work.
renesas_usb3_start will be called to start the work.
If we remove the driver which will call usbhs_remove, there may be
an unfinished work. The possible sequence is as follows:
CPU0 CPU1
renesas_usb3_role_work
renesas_usb3_remove
usb_role_switch_unregister
device_unregister
kfree(sw)
//free usb3->role_sw
usb_role_switch_set_role
//use usb3->role_sw
The usb3->role_sw could be freed under such circumstance and then
used in usb_role_switch_set_role.
This bug was found by static analysis. And note that removing a
driver is a root-only operation, and should never happen in normal
case. But the root user may directly remove the device which
will also trigger the remove function.
Fix it by canceling the work before cleanup in the renesas_usb3_remove.
Fixes: 39facfa01c ("usb: gadget: udc: renesas_usb3: Add register of usb role switch")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20230320062931.505170-1-zyytlz.wz@163.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7bd42fb95eb4f98495ccadf467ad15124208ec49 ]
According to the Tegra Technical Reference Manual, the seq_num
field of control endpoint is not [31:24] but [31:27]. Bit 24
is reserved and bit 26 is splitxstate.
The change fixes the wrong control endpoint's definitions.
Signed-off-by: Wayne Chang <waynec@nvidia.com>
Link: https://lore.kernel.org/r/20220107091349.149798-1-waynec@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 16b1941eac2bd499f065a6739a40ce0011a3d740 upstream.
The syzbot fuzzer found a use-after-free bug:
BUG: KASAN: use-after-free in dev_uevent+0x712/0x780 drivers/base/core.c:2320
Read of size 8 at addr ffff88802b934098 by task udevd/3689
CPU: 2 PID: 3689 Comm: udevd Not tainted 5.17.0-rc4-syzkaller-00229-g4f12b742eb2b #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description.constprop.0.cold+0x8d/0x303 mm/kasan/report.c:255
__kasan_report mm/kasan/report.c:442 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
dev_uevent+0x712/0x780 drivers/base/core.c:2320
uevent_show+0x1b8/0x380 drivers/base/core.c:2391
dev_attr_show+0x4b/0x90 drivers/base/core.c:2094
Although the bug manifested in the driver core, the real cause was a
race with the gadget core. dev_uevent() does:
if (dev->driver)
add_uevent_var(env, "DRIVER=%s", dev->driver->name);
and between the test and the dereference of dev->driver, the gadget
core sets dev->driver to NULL.
The race wouldn't occur if the gadget core registered its devices on
a real bus, using the standard synchronization techniques of the
driver core. However, it's not necessary to make such a large change
in order to fix this bug; all we need to do is make sure that
udc->dev.driver is always NULL.
In fact, there is no reason for udc->dev.driver ever to be set to
anything, let alone to the value it currently gets: the address of the
gadget's driver. After all, a gadget driver only knows how to manage
a gadget, not how to manage a UDC.
This patch simply removes the statements in the gadget core that touch
udc->dev.driver.
Fixes: 2ccea03a8f ("usb: gadget: introduce UDC Class")
CC: <stable@vger.kernel.org>
Reported-and-tested-by: syzbot+348b571beb5eeb70a582@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/YiQgukfFFbBnwJ/9@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7f14c7227f342d9932f9b918893c8814f86d2a0d upstream.
Assure that host may not manipulate the index to point
past endpoint array.
Signed-off-by: Szymon Heidrich <szymon.heidrich@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 459702eea6132888b5c5b64c0e9c626da4ec2493 upstream.
The support the external role switch a variety of situations were
addressed, but the transition from USB_ROLE_HOST to USB_ROLE_NONE
leaves the host up which can cause some error messages when
switching from host to none, to gadget, to none, and then back
to host again.
xhci-hcd ee000000.usb: Abort failed to stop command ring: -110
xhci-hcd ee000000.usb: xHCI host controller not responding, assume dead
xhci-hcd ee000000.usb: HC died; cleaning up
usb 4-1: device not accepting address 6, error -108
usb usb4-port1: couldn't allocate usb_device
After this happens it will not act as a host again.
Fix this by releasing the host mode when transitioning to USB_ROLE_NONE.
Fixes: 0604160d8c ("usb: gadget: udc: renesas_usb3: Enhance role switch support")
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Adam Ford <aford173@gmail.com>
Link: https://lore.kernel.org/r/20220128223603.2362621-1-aford173@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a0548b26901f082684ad1fb3ba397d2de3a1406a upstream.
On 64-bit:
drivers/usb/gadget/udc/fsl_qe_udc.c: In function ‘qe_ep0_rx’:
drivers/usb/gadget/udc/fsl_qe_udc.c:842:13: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
842 | vaddr = (u32)phys_to_virt(in_be32(&bd->buf));
| ^
In file included from drivers/usb/gadget/udc/fsl_qe_udc.c:41:
drivers/usb/gadget/udc/fsl_qe_udc.c:843:28: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
843 | frame_set_data(pframe, (u8 *)vaddr);
| ^
The driver assumes physical and virtual addresses are 32-bit, hence it
cannot work on 64-bit platforms.
Acked-by: Li Yang <leoyang.li@nxp.com>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20211027080849.3276289-1-geert@linux-m68k.org
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 17956b53ebff6a490baf580a836cbd3eae94892b upstream.
This loop is supposed to loop until if reads something other than
CS_IDST or until it times out after 30,000 attempts. But because of
the || vs && bug, it will never time out and instead it will loop a
minimum of 30,000 times.
This bug is quite old but the code is only used in USB_DEVICE_TEST_MODE
so it probably doesn't affect regular usage.
Fixes: 96fe53ef54 ("usb: gadget: r8a66597-udc: add support for TEST_MODE")
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20210906094221.GA10957@kili
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 6f15a2a09cecb7a2faba4a75bbd101f6f962294b ]
If an error occurs after a successful 'clk_prepare_enable()' call, it must
be undone by a corresponding 'clk_disable_unprepare()' call.
This call is already present in the remove function.
Add this call in the error handling path and reorder the code so that the
'clk_prepare_enable()' call happens later in the function.
The goal is to have as much managed resources functions as possible
before the 'clk_prepare_enable()' call in order to keep the error handling
path simple.
While at it, remove the now unneeded 'clk' variable.
Fixes: c87dca0478 ("usb: bdc: Add clock enable for new chips with a separate BDC clock")
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/f8a4a6897deb0c8cb2e576580790303550f15fcd.1629314734.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2af0c5ffadaf9d13eca28409d4238b4e672942d3 ]
If IRQ occurs between calling request_irq() and mv_u3d_eps_init(),
then null pointer dereference occurs since u3d->eps[] wasn't
initialized yet but used in mv_u3d_nuke().
The patch puts registration of the interrupt handler after
initializing of neccesery data.
Found by Linux Driver Verification project (linuxtesting.org).
Fixes: 90fccb529d ("usb: gadget: Gadget directory cleanup - group UDC drivers")
Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Nadezda Lutovinova <lutovinova@ispras.ru>
Link: https://lore.kernel.org/r/20210818141247.4794-1-lutovinova@ispras.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cea45a3bd2dd4d9c35581328f571afd32b3c9f48 ]
soc_device_match() is intended as a last resort, to handle e.g. quirks
that cannot be handled by matching based on a compatible value.
As the device nodes for the Renesas USB 3.0 Peripheral Controller on
R-Car E3 and RZ/G2E do have SoC-specific compatible values, the latter
can and should be used to match against these devices.
This also fixes support for the USB 3.0 Peripheral Controller on the
R-Car E3e (R8A779M6) SoC, which is a different grading of the R-Car E3
(R8A77990) SoC, using the same SoC-specific compatible value.
Fixes: 30025efa8b ("usb: gadget: udc: renesas_usb3: add support for r8a77990")
Fixes: 546970fdab ("usb: gadget: udc: renesas_usb3: add support for r8a774c0")
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/760981fb4cd110d7cbfc9dcffa365e7c8b25c6e5.1628696960.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ecff88e819e31081d41cd05bb199b9bd10e13e90 ]
The driver neglects to check the result of platform_get_irq()'s call and
blithely passes the negative error codes to request_irq() (which takes
*unsigned* IRQ #), causing it to fail with -EINVAL, overriding an original
error code. Stop calling request_irq() with the invalid IRQ #s.
Fixes: 188db4435a ("usb: gadget: s3c: use platform resources")
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Link: https://lore.kernel.org/r/bd69b22c-b484-5a1f-c798-78d4b78405f2@omp.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 50855c31573b02963f0aa2aacfd4ea41c31ae0e0 ]
The driver neglects to check the result of platform_get_irq()'s call and
blithely passes the negative error codes to devm_request_irq() (which takes
*unsigned* IRQ #), causing it to fail with -EINVAL, overriding an original
error code. Stop calling devm_request_irq() with the invalid IRQ #s.
Fixes: 8b2e76687b ("USB: AT91 UDC updates, mostly power management")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Acked-by: Felipe Balbi <balbi@kernel.org>
Link: https://lore.kernel.org/r/6654a224-739a-1a80-12f0-76d920f87b6c@omp.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit e752dbc59e1241b13b8c4f7b6eb582862e7668fe upstream.
The usb3_start_pipen() is called by renesas_usb3_ep_queue() and
usb3_request_done_pipen() so that usb3_start_pipen() is possible
to cause a race when getting usb3_first_req like below:
renesas_usb3_ep_queue()
spin_lock_irqsave()
list_add_tail()
spin_unlock_irqrestore()
usb3_start_pipen()
usb3_first_req = usb3_get_request() --- [1]
--- interrupt ---
usb3_irq_dma_int()
usb3_request_done_pipen()
usb3_get_request()
usb3_start_pipen()
usb3_first_req = usb3_get_request()
...
(the req is possible to be finished in the interrupt)
The usb3_first_req [1] above may have been finished after the interrupt
ended so that this driver caused to start a transfer wrongly. To fix this
issue, getting/checking the usb3_first_req are under spin_lock_irqsave()
in the same section.
Fixes: 746bfe63bb ("usb: gadget: renesas_usb3: add support for Renesas USB3.0 peripheral controller")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20210524060155.1178724-1-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit bd4d607044b961cecbf8c4c2f3bb5da4fb156993 ]
Currently the virtual port_dev device is passed to DMA API, and this is
wrong because the device passed to DMA API calls must be the actual
hardware device performing the DMA.
The patch replaces usb_gadget_map_request/usb_gadget_unmap_request APIs
with usb_gadget_map_request_by_dev/usb_gadget_unmap_request_by_dev APIs
so the DMA capable platform device can be passed to the DMA APIs.
The patch fixes below backtrace detected on Facebook AST2500 OpenBMC
platforms:
[<80106550>] show_stack+0x20/0x24
[<80106868>] dump_stack+0x28/0x30
[<80823540>] __warn+0xfc/0x110
[<8011ac30>] warn_slowpath_fmt+0xb0/0xc0
[<8011ad44>] dma_map_page_attrs+0x24c/0x314
[<8016a27c>] usb_gadget_map_request_by_dev+0x100/0x1e4
[<805cedd8>] usb_gadget_map_request+0x1c/0x20
[<805cefbc>] ast_vhub_epn_queue+0xa0/0x1d8
[<7f02f710>] usb_ep_queue+0x48/0xc4
[<805cd3e8>] ecm_do_notify+0xf8/0x248
[<7f145920>] ecm_set_alt+0xc8/0x1d0
[<7f145c34>] composite_setup+0x680/0x1d30
[<7f00deb8>] ast_vhub_ep0_handle_setup+0xa4/0x1bc
[<7f02ee94>] ast_vhub_dev_irq+0x58/0x84
[<7f0309e0>] ast_vhub_irq+0xb0/0x1c8
[<7f02e118>] __handle_irq_event_percpu+0x50/0x19c
[<8015e5bc>] handle_irq_event_percpu+0x38/0x8c
[<8015e758>] handle_irq_event+0x38/0x4c
Fixes: 7ecca2a408 ("usb/gadget: Add driver for Aspeed SoC virtual hub")
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Tao Ren <rentao.bupt@gmail.com>
Link: https://lore.kernel.org/r/20210331045831.28700-1-rentao.bupt@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c7f755b243494d6043aadcd9a2989cb157958b95 ]
When the EP0 IN request was not completed but less than a packet sent,
it would complete the request successfully. That doesn't make sense
and can't really happen as fotg210_start_dma always sends
min(length, maxpkt) bytes.
Fixes: b84a8dee23 ("usb: gadget: add Faraday fotg210_udc driver")
Signed-off-by: Fabian Vogt <fabian@ritter-vogt.de>
Link: https://lore.kernel.org/r/20210324141115.9384-4-fabian@ritter-vogt.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 755915fc28edfc608fa89a163014acb2f31c1e19 ]
For a 75 Byte request, it would send the first 64 separately, then detect
that the remaining 11 Byte fit into a single DMA, but due to this bug set
the length to the original 75 Bytes. This leads to a DMA failure (which is
ignored...) and the request completes without the remaining bytes having
been sent.
Fixes: b84a8dee23 ("usb: gadget: add Faraday fotg210_udc driver")
Signed-off-by: Fabian Vogt <fabian@ritter-vogt.de>
Link: https://lore.kernel.org/r/20210324141115.9384-2-fabian@ritter-vogt.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fbdbbe6d3ee502b3bdeb4f255196bb45003614be ]
Since we have a separate routine for VBUS sense, the interrupt may occur
before gadget driver is present. Hence, ->setup() call may oops the kernel:
[ 55.245843] BUG: kernel NULL pointer dereference, address: 00000010
...
[ 55.245843] EIP: pch_udc_isr.cold+0x162/0x33f
...
[ 55.245843] <IRQ>
[ 55.245843] ? pch_udc_svc_data_out+0x160/0x160
Check if driver is present before calling ->setup().
Fixes: f646cf9452 ("USB device driver of Topcliff PCH")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210323153626.54908-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 91356fed6afd1c83bf0d3df1fc336d54e38f0458 ]
Either way ~0 will be in the correct byte order, hence
replace cpu_to_le32() by lower_32_bits(). Moreover,
it makes sparse happy, otherwise it complains:
.../pch_udc.c:1813:27: warning: incorrect type in assignment (different base types)
.../pch_udc.c:1813:27: expected unsigned int [usertype] dataptr
.../pch_udc.c:1813:27: got restricted __le32 [usertype]
Fixes: f646cf9452 ("USB device driver of Topcliff PCH")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210323153626.54908-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 50a318cc9b54a36f00beadf77e578a50f3620477 upstream.
The commit d3cb25a121 ("usb: gadget: udc: fix spin_lock in pch_udc")
obviously was not thought through and had made the situation even worse
than it was before. Two changes after almost reverted it. but a few
leftovers have been left as it. With this revert d3cb25a121 completely.
While at it, narrow down the scope of unlocked section to prevent
potential race when prot_stall is assigned.
Fixes: d3cb25a121 ("usb: gadget: udc: fix spin_lock in pch_udc")
Fixes: 9903b6bedd ("usb: gadget: pch-udc: fix lock")
Fixes: 1d23d16a88 ("usb: gadget: pch_udc: reorder spin_[un]lock to avoid deadlock")
Cc: Iago Abal <mail@iagoabal.eu>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210323153626.54908-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4a5d797a9f9c4f18585544237216d7812686a71f upstream.
Fix a general protection fault reported by syzbot due to a race between
gadget_setup() and gadget_unbind() in raw_gadget.
The gadget core is supposed to guarantee that there won't be any more
callbacks to the gadget driver once the driver's unbind routine is
called. That guarantee is enforced in usb_gadget_remove_driver as
follows:
usb_gadget_disconnect(udc->gadget);
if (udc->gadget->irq)
synchronize_irq(udc->gadget->irq);
udc->driver->unbind(udc->gadget);
usb_gadget_udc_stop(udc);
usb_gadget_disconnect turns off the pullup resistor, telling the host
that the gadget is no longer connected and preventing the transmission
of any more USB packets. Any packets that have already been received
are sure to processed by the UDC driver's interrupt handler by the time
synchronize_irq returns.
But this doesn't work with dummy_hcd, because dummy_hcd doesn't use
interrupts; it uses a timer instead. It does have code to emulate the
effect of synchronize_irq, but that code doesn't get invoked at the
right time -- it currently runs in usb_gadget_udc_stop, after the unbind
callback instead of before. Indeed, there's no way for
usb_gadget_remove_driver to invoke this code before the unbind callback.
To fix this, move the synchronize_irq() emulation code to dummy_pullup
so that it runs before unbind. Also, add a comment explaining why it is
necessary to have it there.
Reported-by: syzbot+eb4674092e6cc8d9e0bd@syzkaller.appspotmail.com
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
Link: https://lore.kernel.org/r/20210419033713.3021-1-mail@anirudhrb.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
