5.15-stable review patch. If anyone has any objections, please let me know.
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From: RD Babiera rdbabiera@google.com
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 --- drivers/usb/typec/altmodes/displayport.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-)
--- a/drivers/usb/typec/altmodes/displayport.c +++ b/drivers/usb/typec/altmodes/displayport.c @@ -521,22 +521,26 @@ static ssize_t pin_assignment_show(struc } static DEVICE_ATTR_RW(pin_assignment);
-static struct attribute *dp_altmode_attrs[] = { +static struct attribute *displayport_attrs[] = { &dev_attr_configuration.attr, &dev_attr_pin_assignment.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) { const struct typec_altmode *port = typec_altmode_get_partner(alt); struct dp_altmode *dp; - int ret;
/* FIXME: Port can only be DFP_U. */
@@ -547,10 +551,6 @@ int dp_altmode_probe(struct typec_altmod 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; @@ -576,7 +576,6 @@ void dp_altmode_remove(struct typec_altm { struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
- sysfs_remove_group(&alt->dev.kobj, &dp_altmode_group); cancel_work_sync(&dp->work); } EXPORT_SYMBOL_GPL(dp_altmode_remove); @@ -594,6 +593,7 @@ static struct typec_altmode_driver dp_al .driver = { .name = "typec_displayport", .owner = THIS_MODULE, + .dev_groups = displayport_groups, }, }; module_typec_altmode_driver(dp_altmode_driver);