The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 165376f6b23e9a779850e750fb2eb06622e5a531 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024032759-written-hypnotize-0b2f@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

165376f6b23e ("usb: typec: altmodes/displayport: create sysfs nodes as driver's default device attribute group") 001b0c780eac ("usb: typec: altmodes/displayport: Add hpd sysfs attribute") 7f8113948785 ("usb: typec: altmodes/displayport: Notify drm subsys of hotplug events")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 165376f6b23e9a779850e750fb2eb06622e5a531 Mon Sep 17 00:00:00 2001 From: RD Babiera rdbabiera@google.com Date: Thu, 29 Feb 2024 00:11:02 +0000 Subject: [PATCH] usb: typec: altmodes/displayport: create sysfs nodes as driver's default device attribute group

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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c index f81bec0c7b86..f8ea3054be54 100644 --- a/drivers/usb/typec/altmodes/displayport.c +++ b/drivers/usb/typec/altmodes/displayport.c @@ -559,16 +559,21 @@ static ssize_t hpd_show(struct device *dev, struct device_attribute *attr, char } static DEVICE_ATTR_RO(hpd);

-static struct attribute *dp_altmode_attrs[] = { +static struct attribute *displayport_attrs[] = { &dev_attr_configuration.attr, &dev_attr_pin_assignment.attr, &dev_attr_hpd.attr, NULL };

-static const struct attribute_group dp_altmode_group = { +static const struct attribute_group displayport_group = { .name = "displayport", - .attrs = dp_altmode_attrs, + .attrs = displayport_attrs, +}; + +static const struct attribute_group *displayport_groups[] = { + &displayport_group, + NULL, };

int dp_altmode_probe(struct typec_altmode *alt) @@ -576,7 +581,6 @@ int dp_altmode_probe(struct typec_altmode *alt) const struct typec_altmode *port = typec_altmode_get_partner(alt); struct fwnode_handle *fwnode; struct dp_altmode *dp; - int ret;

/* FIXME: Port can only be DFP_U. */

@@ -587,10 +591,6 @@ int dp_altmode_probe(struct typec_altmode *alt) DP_CAP_PIN_ASSIGN_DFP_D(alt->vdo))) return -ENODEV;

- ret = sysfs_create_group(&alt->dev.kobj, &dp_altmode_group); - if (ret) - return ret; - dp = devm_kzalloc(&alt->dev, sizeof(*dp), GFP_KERNEL); if (!dp) return -ENOMEM; @@ -624,7 +624,6 @@ void dp_altmode_remove(struct typec_altmode *alt) { struct dp_altmode *dp = typec_altmode_get_drvdata(alt);

- sysfs_remove_group(&alt->dev.kobj, &dp_altmode_group); cancel_work_sync(&dp->work);

if (dp->connector_fwnode) { @@ -649,6 +648,7 @@ static struct typec_altmode_driver dp_altmode_driver = { .driver = { .name = "typec_displayport", .owner = THIS_MODULE, + .dev_groups = displayport_groups, }, }; module_typec_altmode_driver(dp_altmode_driver);