FAILED: patch "[PATCH] pps: add an error check in parport_attach" failed to apply to 5.4-stable tree

The patch below does not apply to the 5.4-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 <[email protected]>.

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-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 62c5a01a5711c8e4be8ae7b6f0db663094615d48
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2024100155-blame-emptiness-db5f@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

62c5a01a5711 ("pps: add an error check in parport_attach") 55dbc5b5174d ("pps: remove usage of the deprecated ida_simple_xx() API")

thanks,

greg k-h

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

From 62c5a01a5711c8e4be8ae7b6f0db663094615d48 Mon Sep 17 00:00:00 2001
From: Ma Ke <[email protected]>
Date: Wed, 28 Aug 2024 21:18:14 +0800
Subject: [PATCH] pps: add an error check in parport_attach

In parport_attach, the return value of ida_alloc is unchecked, witch leads to the use of an invalid index value.

To address this issue, index should be checked. When the index value is abnormal, the device should be freed.

Found by code review, compile tested only.

index 63d03a0df5cc..abaffb4e1c1c 100644
@@ -149,6 +149,9 @@ static void parport_attach(struct parport *port)
 	}
 
 	index = ida_alloc(&pps_client_index, GFP_KERNEL);
+	if (index < 0)
+		goto err_free_device;
+
 	memset(&pps_client_cb, 0, sizeof(pps_client_cb));
 	pps_client_cb.private = device;
 	pps_client_cb.irq_func = parport_irq;

@@ -159,7 +162,7 @@ static void parport_attach(struct parport *port)
 						    index);
 	if (!device->pardev) {
 		pr_err("couldn't register with %s\n", port->name);
-		goto err_free;
+		goto err_free_ida;
 	}
 
 	if (parport_claim_or_block(device->pardev) < 0) {

@@ -187,8 +190,9 @@ static void parport_attach(struct parport *port)
 	parport_release(device->pardev);
 err_unregister_dev:
 	parport_unregister_device(device->pardev);
-err_free:
+err_free_ida:
 	ida_free(&pps_client_index, index);
+err_free_device:
 	kfree(device);
 }