FAILED: patch "[PATCH] usb: typec: ucsi: ccg: Fix use-after-free of ucsi on remove" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

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 1f0bdc2884b67de337215079bba166df0cdf4ac5
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026071422-comment-stardust-654c@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From 1f0bdc2884b67de337215079bba166df0cdf4ac5 Mon Sep 17 00:00:00 2001
From: Fan Wu <fanwu01@zju.edu.cn>
Date: Tue, 16 Jun 2026 13:20:11 +0000
Subject: [PATCH] usb: typec: ucsi: ccg: Fix use-after-free of ucsi on remove

The threaded IRQ handler ccg_irq_handler() calls ucsi_notify_common(),
which on a connector-change event calls ucsi_connector_change() and
schedules connector work.  In ucsi_ccg_remove(), ucsi_destroy() frees
uc->ucsi (kfree) before free_irq() is called, so a handler invocation
already in flight may access the freed object after ucsi_destroy().

  CPU 0 (remove)            | CPU 1 (threaded IRQ)
    ucsi_destroy(uc->ucsi)  |   ccg_irq_handler()
      kfree(ucsi) // FREE   |     ucsi_notify_common(uc->ucsi) // USE

Move free_irq() before ucsi_destroy() in the remove path.  It is kept
after ucsi_unregister(): ucsi_unregister() cancels connector work whose
handler issues GET_CONNECTOR_STATUS through ucsi_send_command_common(),
which waits for a completion that is signalled from the IRQ handler, so
the IRQ must stay active until that work has been cancelled.

The probe error path already orders free_irq() before ucsi_destroy().

This bug was found by static analysis.

Fixes: e32fd989ac1c ("usb: typec: ucsi: ccg: Move to the new API")
Cc: stable <stable@kernel.org>
Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://patch.msgid.link/20260616132011.103279-1-fanwu01@zju.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/ucsi/ucsi_ccg.c b/drivers/usb/typec/ucsi/ucsi_ccg.c
index d46ca942026e..91c2958a708c 100644
--- a/drivers/usb/typec/ucsi/ucsi_ccg.c
+++ b/drivers/usb/typec/ucsi/ucsi_ccg.c
@@ -1521,8 +1521,8 @@ static void ucsi_ccg_remove(struct i2c_client *client)
 	cancel_work_sync(&uc->work);
 	pm_runtime_disable(uc->dev);
 	ucsi_unregister(uc->ucsi);
-	ucsi_destroy(uc->ucsi);
 	free_irq(uc->irq, uc);
+	ucsi_destroy(uc->ucsi);
 }
 
 static const struct of_device_id ucsi_ccg_of_match_table[] = {