mei: fix error flow in probe

Dismantle class device last in probe error flow to avoid accessing
freed memory like:

[   87.926774] WARNING: CPU: 9 PID: 518 at kernel/workqueue.c:4234
__flush_work+0x340/0x390
...
[   87.926912] Workqueue: async async_run_entry_fn
[   87.926918] RIP: e030:__flush_work+0x340/0x390
[   87.926923] Code: 26 9d 05 00 65 48 8b 15 26 3c ca 02 48 85 db 48 8b
04 24 48 89 54 24 58 0f 85 de fe ff ff e9 f6 fd ff ff 0f 0b e9 77 ff ff
ff <0f> 0b e9 70 ff ff ff 0f 0b e9 19 ff ff ff e8 7d 8b 0e 01 48 89 de
[   87.926931] RSP: e02b:ffffc900412ebc00 EFLAGS: 00010246
[   87.926936] RAX: 0000000000000000 RBX: ffff888103e55090 RCX: 0000000000000000
[   87.926941] RDX: 000fffffffe00000 RSI: 0000000000000001 RDI: ffffc900412ebc60
[   87.926945] RBP: ffff888103e55090 R08: ffffffffc1266ec8 R09: ffff8881109076e8
[   87.926949] R10: 0000000080040003 R11: 0000000000000000 R12: ffff888103e54000
[   87.926953] R13: ffffc900412ebc18 R14: 0000000000000001 R15: 0000000000000000
[   87.926962] FS:  0000000000000000(0000) GS:ffff888233238000(0000) knlGS:0000000000000000
[   87.926967] CS:  e030 DS: 0000 ES: 0000 CR0: 0000000080050033
[   87.926971] CR2: 00007e7923b32708 CR3: 00000001088df000 CR4: 0000000000050660
[   87.926977] Call Trace:
[   87.926981]  <TASK>
[   87.926987]  ? __call_rcu_common.constprop.0+0x11e/0x310
[   87.926993]  cancel_work_sync+0x5e/0x80
[   87.926999]  mei_cancel_work+0x19/0x40 [mei]
[   87.927051]  mei_me_probe+0x273/0x2b0 [mei_me]
[   87.927060]  local_pci_probe+0x45/0x90
[   87.927066]  pci_call_probe+0x5b/0x180
[   87.927070]  pci_device_probe+0x95/0x140
[   87.927074]  ? driver_sysfs_add+0x57/0xc0
[   87.927079]  really_probe+0xde/0x340
[   87.927083]  ? pm_runtime_barrier+0x54/0x90
[   87.927087]  __driver_probe_device+0x78/0x110
[   87.927092]  driver_probe_device+0x1f/0xa0
[   87.927095]  __driver_attach_async_helper+0x5e/0xe0
[   87.927100]  async_run_entry_fn+0x34/0x130
[   87.927104]  process_one_work+0x18d/0x340
[   87.927108]  worker_thread+0x256/0x3a0
[   87.927111]  ? __pfx_worker_thread+0x10/0x10
[   87.927115]  kthread+0xfc/0x240
[   87.927120]  ? __pfx_kthread+0x10/0x10
[   87.927124]  ? __pfx_kthread+0x10/0x10
[   87.927127]  ret_from_fork+0xf5/0x110
[   87.927132]  ? __pfx_kthread+0x10/0x10
[   87.927136]  ret_from_fork_asm+0x1a/0x30
[   87.927141]  </TASK>

Tested-by: Guenter Roeck <groeck@google.com>
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Closes: https://lore.kernel.org/lkml/aQbYAXPADqfiXUYO@mail-itl/
Reported-by: Guenter Roeck <linux@roeck-us.net>
Closes: https://lore.kernel.org/lkml/8deef7c4-ac75-4db8-91b7-02cf0e39e371@roeck-us.net/
Fixes: 7704e6b ("mei: hook mei_device on class device")
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Link: https://patch.msgid.link/20251102180836.1203314-1-alexander.usyskin@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: ausyskin

drivers/misc/mei/pci-me.c

@@ -223,6 +223,10 @@ static int mei_me_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	hw->mem_addr = pcim_iomap_table(pdev)[0];
 	hw->read_fws = mei_me_read_fws;
 
+	err = mei_register(dev, &pdev->dev);
+	if (err)
+		goto end;
+
 	pci_enable_msi(pdev);
 
 	hw->irq = pdev->irq;
@@ -237,13 +241,9 @@ static int mei_me_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (err) {
 		dev_err(&pdev->dev, "request_threaded_irq failure. irq = %d\n",
 		       pdev->irq);
-		goto end;
+		goto deregister;
 	}
 
-	err = mei_register(dev, &pdev->dev);
-	if (err)
-		goto release_irq;
-
 	if (mei_start(dev)) {
 		dev_err(&pdev->dev, "init hw failure.\n");
 		err = -ENODEV;
@@ -283,11 +283,10 @@ static int mei_me_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	return 0;
 
 deregister:
-	mei_deregister(dev);
-release_irq:
 	mei_cancel_work(dev);
 	mei_disable_interrupts(dev);
 	free_irq(pdev->irq, dev);
+	mei_deregister(dev);
 end:
 	dev_err(&pdev->dev, "initialization failed.\n");
 	return err;

drivers/misc/mei/pci-txe.c

@@ -87,6 +87,10 @@ static int mei_txe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	hw = to_txe_hw(dev);
 	hw->mem_addr = pcim_iomap_table(pdev);
 
+	err = mei_register(dev, &pdev->dev);
+	if (err)
+		goto end;
+
 	pci_enable_msi(pdev);
 
 	/* clear spurious interrupts */
@@ -106,13 +110,9 @@ static int mei_txe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (err) {
 		dev_err(&pdev->dev, "mei: request_threaded_irq failure. irq = %d\n",
 			pdev->irq);
-		goto end;
+		goto deregister;
 	}
 
-	err = mei_register(dev, &pdev->dev);
-	if (err)
-		goto release_irq;
-
 	if (mei_start(dev)) {
 		dev_err(&pdev->dev, "init hw failure.\n");
 		err = -ENODEV;
@@ -145,11 +145,10 @@ static int mei_txe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	return 0;
 
 deregister:
-	mei_deregister(dev);
-release_irq:
 	mei_cancel_work(dev);
 	mei_disable_interrupts(dev);
 	free_irq(pdev->irq, dev);
+	mei_deregister(dev);
 end:
 	dev_err(&pdev->dev, "initialization failed.\n");
 	return err;

drivers/misc/mei/platform-vsc.c

@@ -362,28 +362,27 @@ static int mei_vsc_probe(struct platform_device *pdev)
 
 	ret = mei_register(mei_dev, dev);
 	if (ret)
-		goto err_dereg;
+		goto err;
 
 	ret = mei_start(mei_dev);
 	if (ret) {
 		dev_err_probe(dev, ret, "init hw failed\n");
-		goto err_cancel;
+		goto err;
 	}
 
 	pm_runtime_enable(mei_dev->parent);
 
 	return 0;
 
-err_dereg:
-	mei_deregister(mei_dev);
-
-err_cancel:
+err:
 	mei_cancel_work(mei_dev);
 
 	vsc_tp_register_event_cb(tp, NULL, NULL);
 
 	mei_disable_interrupts(mei_dev);
 
+	mei_deregister(mei_dev);
+
 	return ret;
 }