FAILED: patch "[PATCH] media: nxp: imx8-isi: Fix use-after-free on remove" failed to apply to 6.12-stable tree

The patch below does not apply to the 6.12-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-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x b670bf89824ede5d07d20bb9bfbafb754846081d
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026071342-backfire-varsity-a0ef@gregkh' --subject-prefix 'PATCH 6.12.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

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

From b670bf89824ede5d07d20bb9bfbafb754846081d Mon Sep 17 00:00:00 2001
From: Xiaolei Wang <[email protected]>
Date: Thu, 7 May 2026 12:13:15 +0800
Subject: [PATCH] media: nxp: imx8-isi: Fix use-after-free on remove

KASAN reports a slab-use-after-free in __media_entity_remove_link() during rmmod of imx8_isi:

  BUG: KASAN: slab-use-after-free in __media_entity_remove_link+0x608/0x650
  Read of size 2 at addr ffff0000d47cb02a by task rmmod/724

  Call trace:
   __media_entity_remove_link+0x608/0x650
   __media_entity_remove_links+0x78/0x144
   __media_device_unregister_entity+0x150/0x280
   media_device_unregister_entity+0x48/0x68
   v4l2_device_unregister_subdev+0x158/0x300
   v4l2_async_unbind_subdev_one+0x22c/0x358
   v4l2_async_nf_unbind_all_subdevs+0xfc/0x1c0
   v4l2_async_nf_unregister+0x5c/0x14c
   mxc_isi_remove+0x124/0x2a0 [imx8_isi]

  Allocated by task 249:
   __kmalloc_noprof+0x27c/0x690
   mxc_isi_crossbar_init+0x22c/0x560 [imx8_isi]

  Freed by task 724:
   kfree+0x1e4/0x5b0
   mxc_isi_crossbar_cleanup+0x34/0x80 [imx8_isi]
   mxc_isi_remove+0x11c/0x2a0 [imx8_isi]

The problem is that mxc_isi_remove() calls mxc_isi_crossbar_cleanup() before mxc_isi_v4l2_cleanup(). The crossbar cleanup frees the media entity pads, but the subsequent v4l2 cleanup still tries to remove media links that reference those pads.

Fix this by calling mxc_isi_v4l2_cleanup() before mxc_isi_crossbar_cleanup() to ensure all media entities are properly unregistered while the pads are still valid.

index 4bf8570e1b9e..2d639b789910 100644
@@ -556,8 +556,8 @@ static void mxc_isi_remove(struct platform_device *pdev)
 		mxc_isi_pipe_cleanup(pipe);
 	}
 
-	mxc_isi_crossbar_cleanup(&isi->crossbar);
 	mxc_isi_v4l2_cleanup(isi);
+	mxc_isi_crossbar_cleanup(&isi->crossbar);
 }
 
 static const struct of_device_id mxc_isi_of_match[] = {

From: Frank Li <[email protected]>

[ Upstream commit 078161dd44d6f848a62a473206d69025607736ec ]

Use devm_pm_runtime_enable() to simplify code. Change to use dev_err_probe() because previous goto change to return.

No functional change.

Stable-dep-of: b670bf89824e ("media: nxp: imx8-isi: Fix use-after-free on remove")

---
 .../media/platform/nxp/imx8-isi/imx8-isi-core.c  | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

index c2013995049c60..560d58ff2db8bd 100644
@@ -472,13 +472,14 @@ static int mxc_isi_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	pm_runtime_enable(dev);
+	ret = devm_pm_runtime_enable(dev);
+	if (ret)
+		return ret;
 
 	ret = mxc_isi_crossbar_init(isi);
-	if (ret) {
-		dev_err(dev, "Failed to initialize crossbar: %d\n", ret);
-		goto err_pm;
-	}
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Failed to initialize crossbar\n");
 
 	for (i = 0; i < isi->pdata->num_channels; ++i) {
 		ret = mxc_isi_pipe_init(isi, i);

@@ -501,8 +502,7 @@ static int mxc_isi_probe(struct platform_device *pdev)
 
 err_xbar:
 	mxc_isi_crossbar_cleanup(&isi->crossbar);
-err_pm:
-	pm_runtime_disable(isi->dev);
+
 	return ret;
 }
 

@@ -521,8 +521,6 @@ static void mxc_isi_remove(struct platform_device *pdev)
 
 	mxc_isi_crossbar_cleanup(&isi->crossbar);
 	mxc_isi_v4l2_cleanup(isi);
-
-	pm_runtime_disable(isi->dev);
 }
 
 static const struct of_device_id mxc_isi_of_match[] = {

2.53.0

From: Xiaolei Wang <[email protected]>

[ Upstream commit b670bf89824ede5d07d20bb9bfbafb754846081d ]

KASAN reports a slab-use-after-free in __media_entity_remove_link() during rmmod of imx8_isi:

  BUG: KASAN: slab-use-after-free in __media_entity_remove_link+0x608/0x650
  Read of size 2 at addr ffff0000d47cb02a by task rmmod/724

  Call trace:
   __media_entity_remove_link+0x608/0x650
   __media_entity_remove_links+0x78/0x144
   __media_device_unregister_entity+0x150/0x280
   media_device_unregister_entity+0x48/0x68
   v4l2_device_unregister_subdev+0x158/0x300
   v4l2_async_unbind_subdev_one+0x22c/0x358
   v4l2_async_nf_unbind_all_subdevs+0xfc/0x1c0
   v4l2_async_nf_unregister+0x5c/0x14c
   mxc_isi_remove+0x124/0x2a0 [imx8_isi]

  Allocated by task 249:
   __kmalloc_noprof+0x27c/0x690
   mxc_isi_crossbar_init+0x22c/0x560 [imx8_isi]

  Freed by task 724:
   kfree+0x1e4/0x5b0
   mxc_isi_crossbar_cleanup+0x34/0x80 [imx8_isi]
   mxc_isi_remove+0x11c/0x2a0 [imx8_isi]

The problem is that mxc_isi_remove() calls mxc_isi_crossbar_cleanup() before mxc_isi_v4l2_cleanup(). The crossbar cleanup frees the media entity pads, but the subsequent v4l2 cleanup still tries to remove media links that reference those pads.

Fix this by calling mxc_isi_v4l2_cleanup() before mxc_isi_crossbar_cleanup() to ensure all media entities are properly unregistered while the pads are still valid.

---
 drivers/media/platform/nxp/imx8-isi/imx8-isi-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 560d58ff2db8bd..a161dc32689542 100644
@@ -519,8 +519,8 @@ static void mxc_isi_remove(struct platform_device *pdev)
 		mxc_isi_pipe_cleanup(pipe);
 	}
 
-	mxc_isi_crossbar_cleanup(&isi->crossbar);
 	mxc_isi_v4l2_cleanup(isi);
+	mxc_isi_crossbar_cleanup(&isi->crossbar);
 }
 
 static const struct of_device_id mxc_isi_of_match[] = {

2.53.0