Описание
In the Linux kernel, the following vulnerability has been resolved: drm/msm/dp: skip PUSH_IDLE when the link was never enabled msm_dp_display_atomic_enable() returns early when link training fails, leaving ->power_on false and the main link down. msm_dp_display_atomic_disable() nevertheless writes DP_STATE_CTRL_PUSH_IDLE and waits for an idle-pattern completion that cannot arrive, so every failed enable is followed by "PUSH_IDLE pattern timedout". Every other step of the teardown is already gated on that flag: msm_dp_display_disable(), called from .atomic_post_disable(), returns early on !power_on. The PUSH_IDLE write is the only one that is not, so the controller's runtime-PM reference is then dropped without the link having been taken down. On glymur (Snapdragon X2 Elite) the consequence is not a warning. The SoC does not survive it: TrustZone force-stops the SOCCP and ADSP remote processors and the machine resets silently about 50 ms later, with no oops and no panic. On an ASUS Zenbook A16 (UX3607OA), whose eDP panel does not currently train, this reproduces without any compositor or GPU involvement:
eDP enable has already failed with "Failed link training (rc=-104)"
echo 1 > /sys/class/graphics/fb0/blank
[535.645455] === marker ===
[535.694833] qcom_q6v5_pas d00000.remoteproc: fatal error received:
sys_m_smsm.c:512:TZ force stop
[535.694875] remoteproc remoteproc0: crash detected in soccp: type fatal error
[535.728857] qcom_q6v5_pas 6800000.remoteproc: fatal error received:
sys_m_smsm.c:783:err fatal notification received from TZ
Gate the PUSH_IDLE write on ->power_on so the disable path is consistent
with the rest of the teardown. With this applied the same sequence is
harmless and the machine stays up; without it, it resets every time.
The unconditional write dates back to the original DP driver
(c943b4948b58 ("drm/msm/dp: add displayPort driver support")), but the
surrounding code has been restructured several times since, so no Fixes:
tag is offered.
Note that the eDP link-training failure that exposes this on the A16 is a
separate problem in the glymur eDP PHY and is reported separately; this
change is about not damaging the machine when training fails, for whatever
reason.
Tested on ASUS Zenbook A16 (UX3607OA), Snapdragon X2 Elite Extreme, on
linux-next next-20260803 and next-20260807. The machine has since been
running next-20260807 with this patch as its daily driver.
Patchwork: https://patchwork.freedesktop.org/patch/745167/
A flaw was found in the Linux kernel's Qualcomm MSM DisplayPort driver. When display link training fails to initialize the connection, the driver improperly attempts an idle teardown sequence on an unpowered controller. A local user could trigger this condition during display state transitions, leading to a fatal system reset and Denial of Service (DoS).
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Not affected | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Not affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Not affected |
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Дополнительная информация
Статус:
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: drm/msm/dp: skip PUSH_IDLE when the link was never enabled msm_dp_display_atomic_enable() returns early when link training fails, leaving ->power_on false and the main link down. msm_dp_display_atomic_disable() nevertheless writes DP_STATE_CTRL_PUSH_IDLE and waits for an idle-pattern completion that cannot arrive, so every failed enable is followed by "PUSH_IDLE pattern timedout". Every other step of the teardown is already gated on that flag: msm_dp_display_disable(), called from .atomic_post_disable(), returns early on !power_on. The PUSH_IDLE write is the only one that is not, so the controller's runtime-PM reference is then dropped without the link having been taken down. On glymur (Snapdragon X2 Elite) the consequence is not a warning. The SoC does not survive it: TrustZone force-stops the SOCCP and ADSP remote processors and the machine resets silently about 50 ms later, with no oops and no panic. On an ASUS Z...
In the Linux kernel, the following vulnerability has been resolved: drm/msm/dp: skip PUSH_IDLE when the link was never enabled msm_dp_display_atomic_enable() returns early when link training fails, leaving ->power_on false and the main link down. msm_dp_display_atomic_disable() nevertheless writes DP_STATE_CTRL_PUSH_IDLE and waits for an idle-pattern completion that cannot arrive, so every failed enable is followed by "PUSH_IDLE pattern timedout". Every other step of the teardown is already gated on that flag: msm_dp_display_disable(), called from .atomic_post_disable(), returns early on !power_on. The PUSH_IDLE write is the only one that is not, so the controller's runtime-PM reference is then dropped without the link having been taken down. On glymur (Snapdragon X2 Elite) the consequence is not a warning. The SoC does not survive it: TrustZone force-stops the SOCCP and ADSP remote processors and the machine resets silently about 50 ms later, with no oops and no panic. On an ASUS
In the Linux kernel, the following vulnerability has been resolved: d ...
In the Linux kernel, the following vulnerability has been resolved: drm/msm/dp: skip PUSH_IDLE when the link was never enabled msm_dp_display_atomic_enable() returns early when link training fails, leaving ->power_on false and the main link down. msm_dp_display_atomic_disable() nevertheless writes DP_STATE_CTRL_PUSH_IDLE and waits for an idle-pattern completion that cannot arrive, so every failed enable is followed by "PUSH_IDLE pattern timedout". Every other step of the teardown is already gated on that flag: msm_dp_display_disable(), called from .atomic_post_disable(), returns early on !power_on. The PUSH_IDLE write is the only one that is not, so the controller's runtime-PM reference is then dropped without the link having been taken down. On glymur (Snapdragon X2 Elite) the consequence is not a warning. The SoC does not survive it: TrustZone force-stops the SOCCP and ADSP remote processors and the machine resets silently about 50 ms later, with no oops and no panic. On an AS...
5.5 Medium
CVSS3