linux.git/drivers/usb/typec/altmodes, branch v5.10.258 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git usb: typec: displayport: Fix potential deadlock 2025-07-17T16:27:51+00:00 Andrei Kuchynski akuchynski@chromium.org 2025-06-24T13:32:46+00:00 eb08fca56f1f39e4038cb9bac9864464b13b00aa commit 099cf1fbb8afc3771f408109f62bdec66f85160e upstream. The deadlock can occur due to a recursive lock acquisition of `cros_typec_altmode_data::mutex`. The call chain is as follows: 1. cros_typec_altmode_work() acquires the mutex 2. typec_altmode_vdm() -> dp_altmode_vdm() -> 3. typec_altmode_exit() -> cros_typec_altmode_exit() 4. cros_typec_altmode_exit() attempts to acquire the mutex again To prevent this, defer the `typec_altmode_exit()` call by scheduling it rather than calling it directly from within the mutex-protected context. Cc: stable <stable@kernel.org> Fixes: b4b38ffb38c9 ("usb: typec: displayport: Receive DP Status Update NAK request exit dp altmode") Signed-off-by: Andrei Kuchynski <akuchynski@chromium.org> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20250624133246.3936737-1-akuchynski@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 099cf1fbb8afc3771f408109f62bdec66f85160e upstream.

The deadlock can occur due to a recursive lock acquisition of
`cros_typec_altmode_data::mutex`.
The call chain is as follows:
1. cros_typec_altmode_work() acquires the mutex
2. typec_altmode_vdm() -> dp_altmode_vdm() ->
3. typec_altmode_exit() -> cros_typec_altmode_exit()
4. cros_typec_altmode_exit() attempts to acquire the mutex again

To prevent this, defer the `typec_altmode_exit()` call by scheduling
it rather than calling it directly from within the mutex-protected
context.

Cc: stable <stable@kernel.org>
Fixes: b4b38ffb38c9 ("usb: typec: displayport: Receive DP Status Update NAK request exit dp altmode")
Signed-off-by: Andrei Kuchynski <akuchynski@chromium.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20250624133246.3936737-1-akuchynski@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: typec: altmodes/displayport: do not index invalid pin_assignments 2025-07-17T16:27:45+00:00 RD Babiera rdbabiera@google.com 2025-06-18T22:49:42+00:00 114a977e0f6bf278e05eade055e13fc271f69cf7 commit af4db5a35a4ef7a68046883bfd12468007db38f1 upstream. A poorly implemented DisplayPort Alt Mode port partner can indicate that its pin assignment capabilities are greater than the maximum value, DP_PIN_ASSIGN_F. In this case, calls to pin_assignment_show will cause a BRK exception due to an out of bounds array access. Prevent for loop in pin_assignment_show from accessing invalid values in pin_assignments by adding DP_PIN_ASSIGN_MAX value in typec_dp.h and using i < DP_PIN_ASSIGN_MAX as a loop condition. Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode") Cc: stable <stable@kernel.org> Signed-off-by: RD Babiera <rdbabiera@google.com> Reviewed-by: Badhri Jagan Sridharan <badhri@google.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20250618224943.3263103-2-rdbabiera@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit af4db5a35a4ef7a68046883bfd12468007db38f1 upstream.

A poorly implemented DisplayPort Alt Mode port partner can indicate
that its pin assignment capabilities are greater than the maximum
value, DP_PIN_ASSIGN_F. In this case, calls to pin_assignment_show
will cause a BRK exception due to an out of bounds array access.

Prevent for loop in pin_assignment_show from accessing
invalid values in pin_assignments by adding DP_PIN_ASSIGN_MAX
value in typec_dp.h and using i < DP_PIN_ASSIGN_MAX as a loop
condition.

Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode")
Cc: stable <stable@kernel.org>
Signed-off-by: RD Babiera <rdbabiera@google.com>
Reviewed-by: Badhri Jagan Sridharan <badhri@google.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20250618224943.3263103-2-rdbabiera@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: typec: displayport: Receive DP Status Update NAK request exit dp altmode 2025-07-17T16:27:37+00:00 Jos Wang joswang@lenovo.com 2025-02-09T07:19:26+00:00 e3fb6c2c3939b4aad203cacdd613a62ce1fd032c [ Upstream commit b4b38ffb38c91afd4dc387608db26f6fc34ed40b ] Although some Type-C DRD devices that do not support the DP Sink function (such as Huawei Mate 40Pro), the Source Port initiates Enter Mode CMD, but the device responds to Enter Mode ACK, the Source port then initiates DP Status Update CMD, and the device responds to DP Status Update NAK. As PD2.0 spec ("6.4.4.3.4 Enter Mode Command")，A DR_Swap Message Shall Not be sent during Modal Operation between the Port Partners. At this time, the source port initiates DR_Swap message through the "echo device > /sys/class/typec/port0/data_role" command to switch the data role from host to device. The device will initiate a Hard Reset for recovery, resulting in the failure of data role swap. Therefore, when DP Status Update NAK is received, Exit Mode CMD is initiated to exit the currently entered DP altmode. Signed-off-by: Jos Wang <joswang@lenovo.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20250209071926.69625-1-joswang1221@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b4b38ffb38c91afd4dc387608db26f6fc34ed40b ]

Although some Type-C DRD devices that do not support the DP Sink
function (such as Huawei Mate 40Pro), the Source Port initiates
Enter Mode CMD, but the device responds to Enter Mode ACK, the
Source port then initiates DP Status Update CMD, and the device
responds to DP Status Update NAK.

As PD2.0 spec ("6.4.4.3.4 Enter Mode Command")，A DR_Swap Message
Shall Not be sent during Modal Operation between the Port Partners.
At this time, the source port initiates DR_Swap message through the
"echo device > /sys/class/typec/port0/data_role" command to switch
the data role from host to device. The device will initiate a Hard
Reset for recovery, resulting in the failure of data role swap.

Therefore, when DP Status Update NAK is received, Exit Mode CMD is
initiated to exit the currently entered DP altmode.

Signed-off-by: Jos Wang <joswang@lenovo.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20250209071926.69625-1-joswang1221@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
usb: typec: altmodes/displayport: create sysfs nodes as driver's default device attribute group 2025-06-04T12:36:58+00:00 RD Babiera rdbabiera@google.com 2024-02-29T00:11:02+00:00 6b989ea1c479533ab8dbfbeb1704c94b1d3320da commit 165376f6b23e9a779850e750fb2eb06622e5a531 upstream. The DisplayPort driver's sysfs nodes may be present to the userspace before typec_altmode_set_drvdata() completes in dp_altmode_probe. This means that a sysfs read can trigger a NULL pointer error by deferencing dp->hpd in hpd_show or dp->lock in pin_assignment_show, as dev_get_drvdata() returns NULL in those cases. Remove manual sysfs node creation in favor of adding attribute group as default for devices bound to the driver. The ATTRIBUTE_GROUPS() macro is not used here otherwise the path to the sysfs nodes is no longer compliant with the ABI. Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode") Cc: stable@vger.kernel.org Signed-off-by: RD Babiera <rdbabiera@google.com> Link: https://lore.kernel.org/r/20240229001101.3889432-2-rdbabiera@google.com [Minor conflict resolved due to code context change.] Signed-off-by: Jianqi Ren <jianqi.ren.cn@windriver.com> Signed-off-by: He Zhe <zhe.he@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 165376f6b23e9a779850e750fb2eb06622e5a531 upstream.

The DisplayPort driver's sysfs nodes may be present to the userspace before
typec_altmode_set_drvdata() completes in dp_altmode_probe. This means that
a sysfs read can trigger a NULL pointer error by deferencing dp->hpd in
hpd_show or dp->lock in pin_assignment_show, as dev_get_drvdata() returns
NULL in those cases.

Remove manual sysfs node creation in favor of adding attribute group as
default for devices bound to the driver. The ATTRIBUTE_GROUPS() macro is
not used here otherwise the path to the sysfs nodes is no longer compliant
with the ABI.

Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode")
Cc: stable@vger.kernel.org
Signed-off-by: RD Babiera <rdbabiera@google.com>
Link: https://lore.kernel.org/r/20240229001101.3889432-2-rdbabiera@google.com
[Minor conflict resolved due to code context change.]
Signed-off-by: Jianqi Ren <jianqi.ren.cn@windriver.com>
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: typec: altmodes/displayport: Signal hpd low when exiting mode 2023-10-25T09:54:22+00:00 RD Babiera rdbabiera@google.com 2023-10-09T21:00:58+00:00 9ed14f807f4f768ab06de395c1dfea7a31eea55e [ Upstream commit 89434b069e460967624903b049e5cf5c9e6b99b9 ] Upon receiving an ACK for a sent EXIT_MODE message, the DisplayPort driver currently resets the status and configuration of the port partner. The hpd signal is not updated despite being part of the status, so the Display stack can still transmit video despite typec_altmode_exit placing the lanes in a Safe State. Set hpd to low when a sent EXIT_MODE message is ACK'ed. Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode") Cc: stable@vger.kernel.org Signed-off-by: RD Babiera <rdbabiera@google.com> Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20231009210057.3773877-2-rdbabiera@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 89434b069e460967624903b049e5cf5c9e6b99b9 ]

Upon receiving an ACK for a sent EXIT_MODE message, the DisplayPort
driver currently resets the status and configuration of the port partner.
The hpd signal is not updated despite being part of the status, so the
Display stack can still transmit video despite typec_altmode_exit placing
the lanes in a Safe State.

Set hpd to low when a sent EXIT_MODE message is ACK'ed.

Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode")
Cc: stable@vger.kernel.org
Signed-off-by: RD Babiera <rdbabiera@google.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20231009210057.3773877-2-rdbabiera@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
usb: typec: altmodes/displayport: Notify drm subsys of hotplug events 2023-10-25T09:54:22+00:00 Hans de Goede hdegoede@redhat.com 2021-08-17T21:52:01+00:00 f25a13d318b8eb6fb48673376b585a990e605e93 [ Upstream commit 7f811394878535ed9a6849717de8c2959ae38899 ] Use the new drm_connector_oob_hotplug_event() functions to let drm/kms drivers know about DisplayPort over Type-C hotplug events. Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Lyude Paul <lyude@redhat.com> Link: https://lore.kernel.org/r/20210817215201.795062-9-hdegoede@redhat.com Stable-dep-of: 89434b069e46 ("usb: typec: altmodes/displayport: Signal hpd low when exiting mode") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 7f811394878535ed9a6849717de8c2959ae38899 ]

Use the new drm_connector_oob_hotplug_event() functions to let drm/kms
drivers know about DisplayPort over Type-C hotplug events.

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://lore.kernel.org/r/20210817215201.795062-9-hdegoede@redhat.com
Stable-dep-of: 89434b069e46 ("usb: typec: altmodes/displayport: Signal hpd low when exiting mode")
Signed-off-by: Sasha Levin <sashal@kernel.org>
usb: typec: altmodes/displayport: fix pin_assignment_show 2023-05-30T11:57:54+00:00 Badhri Jagan Sridharan badhri@google.com 2023-05-08T21:44:43+00:00 ff466f77d0a56719979c4234abd412abd98eae8f commit d8f28269dd4bf9b55c3fb376ae31512730a96fce upstream. This patch fixes negative indexing of buf array in pin_assignment_show when get_current_pin_assignments returns 0 i.e. no compatible pin assignments are found. BUG: KASAN: use-after-free in pin_assignment_show+0x26c/0x33c ... Call trace: dump_backtrace+0x110/0x204 dump_stack_lvl+0x84/0xbc print_report+0x358/0x974 kasan_report+0x9c/0xfc __do_kernel_fault+0xd4/0x2d4 do_bad_area+0x48/0x168 do_tag_check_fault+0x24/0x38 do_mem_abort+0x6c/0x14c el1_abort+0x44/0x68 el1h_64_sync_handler+0x64/0xa4 el1h_64_sync+0x78/0x7c pin_assignment_show+0x26c/0x33c dev_attr_show+0x50/0xc0 Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode") Cc: stable@vger.kernel.org Signed-off-by: Badhri Jagan Sridharan <badhri@google.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20230508214443.893436-1-badhri@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d8f28269dd4bf9b55c3fb376ae31512730a96fce upstream.

This patch fixes negative indexing of buf array in pin_assignment_show
when get_current_pin_assignments returns 0 i.e. no compatible pin
assignments are found.

BUG: KASAN: use-after-free in pin_assignment_show+0x26c/0x33c
...
Call trace:
dump_backtrace+0x110/0x204
dump_stack_lvl+0x84/0xbc
print_report+0x358/0x974
kasan_report+0x9c/0xfc
__do_kernel_fault+0xd4/0x2d4
do_bad_area+0x48/0x168
do_tag_check_fault+0x24/0x38
do_mem_abort+0x6c/0x14c
el1_abort+0x44/0x68
el1h_64_sync_handler+0x64/0xa4
el1h_64_sync+0x78/0x7c
pin_assignment_show+0x26c/0x33c
dev_attr_show+0x50/0xc0

Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode")
Cc: stable@vger.kernel.org
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20230508214443.893436-1-badhri@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: typec: altmodes/displayport: Fix configure initial pin assignment 2023-04-20T10:10:22+00:00 RD Babiera rdbabiera@google.com 2023-03-29T21:51:59+00:00 9d1f2a6b8d9a3fab2611e5bedeeb21da5b4bd032 commit eddebe39602efe631b83ff8d03f26eba12cfd760 upstream. While determining the initial pin assignment to be sent in the configure message, using the DP_PIN_ASSIGN_DP_ONLY_MASK mask causes the DFP_U to send both Pin Assignment C and E when both are supported by the DFP_U and UFP_U. The spec (Table 5-7 DFP_U Pin Assignment Selection Mandates, VESA DisplayPort Alt Mode Standard v2.0) indicates that the DFP_U never selects Pin Assignment E when Pin Assignment C is offered. Update the DP_PIN_ASSIGN_DP_ONLY_MASK conditional to intially select only Pin Assignment C if it is available. Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode") Cc: stable@vger.kernel.org Signed-off-by: RD Babiera <rdbabiera@google.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20230329215159.2046932-1-rdbabiera@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit eddebe39602efe631b83ff8d03f26eba12cfd760 upstream.

While determining the initial pin assignment to be sent in the configure
message, using the DP_PIN_ASSIGN_DP_ONLY_MASK mask causes the DFP_U to
send both Pin Assignment C and E when both are supported by the DFP_U and
UFP_U. The spec (Table 5-7 DFP_U Pin Assignment Selection Mandates,
VESA DisplayPort Alt Mode Standard v2.0) indicates that the DFP_U never
selects Pin Assignment E when Pin Assignment C is offered.

Update the DP_PIN_ASSIGN_DP_ONLY_MASK conditional to intially select only
Pin Assignment C if it is available.

Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode")
Cc: stable@vger.kernel.org
Signed-off-by: RD Babiera <rdbabiera@google.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20230329215159.2046932-1-rdbabiera@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: typec: altmodes/displayport: Fix probe pin assign check 2023-02-15T16:22:26+00:00 Prashant Malani pmalani@chromium.org 2023-02-08T20:53:19+00:00 4f518a4a79bddfd1f87fe62a85bdece5ee809614 commit 54e5c00a4eb0a4c663445b245f641bbfab142430 upstream. While checking Pin Assignments of the port and partner during probe, we don't take into account whether the peripheral is a plug or receptacle. This manifests itself in a mode entry failure on certain docks and dongles with captive cables. For instance, the Startech.com Type-C to DP dongle (Model #CDP2DP) advertises its DP VDO as 0x405. This would fail the Pin Assignment compatibility check, despite it supporting Pin Assignment C as a UFP. Update the check to use the correct DP Pin Assign macros that take the peripheral's receptacle bit into account. Fixes: c1e5c2f0cb8a ("usb: typec: altmodes/displayport: correct pin assignment for UFP receptacles") Cc: stable@vger.kernel.org Reported-by: Diana Zigterman <dzigterman@chromium.org> Signed-off-by: Prashant Malani <pmalani@chromium.org> Link: https://lore.kernel.org/r/20230208205318.131385-1-pmalani@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 54e5c00a4eb0a4c663445b245f641bbfab142430 upstream.

While checking Pin Assignments of the port and partner during probe, we
don't take into account whether the peripheral is a plug or receptacle.

This manifests itself in a mode entry failure on certain docks and
dongles with captive cables. For instance, the Startech.com Type-C to DP
dongle (Model #CDP2DP) advertises its DP VDO as 0x405. This would fail
the Pin Assignment compatibility check, despite it supporting
Pin Assignment C as a UFP.

Update the check to use the correct DP Pin Assign macros that
take the peripheral's receptacle bit into account.

Fixes: c1e5c2f0cb8a ("usb: typec: altmodes/displayport: correct pin assignment for UFP receptacles")
Cc: stable@vger.kernel.org
Reported-by: Diana Zigterman <dzigterman@chromium.org>
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Link: https://lore.kernel.org/r/20230208205318.131385-1-pmalani@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: typec: altmodes/displayport: Fix pin assignment calculation 2023-01-24T06:20:00+00:00 Prashant Malani pmalani@chromium.org 2023-01-11T02:05:42+00:00 6107a8f15c0f1908c550729466f2b405d7eefc24 commit 9682b41e52cc9f42f5c33caf410464392adaef04 upstream. Commit c1e5c2f0cb8a ("usb: typec: altmodes/displayport: correct pin assignment for UFP receptacles") fixed the pin assignment calculation to take into account whether the peripheral was a plug or a receptacle. But the "pin_assignments" sysfs logic was not updated. Address this by using the macros introduced in the aforementioned commit in the sysfs logic too. Fixes: c1e5c2f0cb8a ("usb: typec: altmodes/displayport: correct pin assignment for UFP receptacles") Cc: stable@vger.kernel.org Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Prashant Malani <pmalani@chromium.org> Reviewed-by: Benson Leung <bleung@chromium.org> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20230111020546.3384569-2-pmalani@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9682b41e52cc9f42f5c33caf410464392adaef04 upstream.

Commit c1e5c2f0cb8a ("usb: typec: altmodes/displayport: correct pin
assignment for UFP receptacles") fixed the pin assignment calculation
to take into account whether the peripheral was a plug or a receptacle.

But the "pin_assignments" sysfs logic was not updated. Address this by
using the macros introduced in the aforementioned commit in the sysfs
logic too.

Fixes: c1e5c2f0cb8a ("usb: typec: altmodes/displayport: correct pin assignment for UFP receptacles")
Cc: stable@vger.kernel.org
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Reviewed-by: Benson Leung <bleung@chromium.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20230111020546.3384569-2-pmalani@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>