[PATCH] usb: typec: ucsi: glink: fix use-after-free of ucsi on remove
COLD26d
From: Fan Wu <hidden>
Date: 2026-09-08 06:03:28
Also in:
linux-usb, lkml
Subsystem:
the rest, usb subsystem, usb typec class · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Heikki Krogerus
The pmic_glink client is released by the devres cleanup, which runs
after pmic_glink_ucsi_remove() has returned, so its notification
callbacks can queue work until then. Work that runs after
ucsi_unregister() has been called touches freed state: it dereferences
the connector array that ucsi_unregister() freed, or registers and
unregisters the instance a second time.
Disable both work items with disable_work_sync() before unregistering,
and unregister only if the instance is still registered.
This issue was found by an in-house static analysis tool.
Fixes: 62b5412b1f4a ("usb: typec: ucsi: add PMIC Glink UCSI driver")
Cc: stable@vger.kernel.org
Assisted-by: Codex:gpt-5.6
Link: https://lore.kernel.org/r/20260227190430.889-1-nathan.c.rebello@gmail.com (local)
Co-developed-by: Song Li <redacted>
Signed-off-by: Song Li <redacted>
Signed-off-by: Fan Wu <redacted>
---
drivers/usb/typec/ucsi/ucsi_glink.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/typec/ucsi/ucsi_glink.c b/drivers/usb/typec/ucsi/ucsi_glink.c
index 12e07b9fe..1db0c88d8 100644
--- a/drivers/usb/typec/ucsi/ucsi_glink.c
+++ b/drivers/usb/typec/ucsi/ucsi_glink.c@@ -362,6 +362,10 @@ static void pmic_glink_ucsi_destroy(void *data) { struct pmic_glink_ucsi *ucsi = data; + /* Drain the work items before ucsi_destroy() frees the ucsi instance */ + cancel_work_sync(&ucsi->notify_work); + cancel_work_sync(&ucsi->register_work); + /* Protect to make sure we're not in a middle of a transaction from a glink callback */ mutex_lock(&ucsi->lock); ucsi_destroy(ucsi->ucsi);
@@ -467,8 +471,15 @@ static void pmic_glink_ucsi_remove(struct auxiliary_device *adev) { struct pmic_glink_ucsi *ucsi = dev_get_drvdata(&adev->dev); - /* Unregister first to stop having read & writes */ - ucsi_unregister(ucsi->ucsi); + /* Callbacks can queue work until devres releases the client */ + disable_work_sync(&ucsi->notify_work); + disable_work_sync(&ucsi->register_work); + + /* register_work may have unregistered the instance already */ + if (ucsi->ucsi_registered) { + ucsi->ucsi_registered = false; + ucsi_unregister(ucsi->ucsi); + } } static const struct auxiliary_device_id pmic_glink_ucsi_id_table[] = {