On Sun, Nov 02, 2025 at 08:08:36PM +0200, Alexander Usyskin wrote:
> 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]
> [ 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]
>
> Tested-by: Guenter Roeck
> Reported-by: Marek Marczykowski-Górecki
> Closes: https://lore.kernel.org/lkml/aQbYAXPADqfiXUYO@mail-itl/
> Reported-by: Guenter Roeck
> Closes: https://lore.kernel.org/lkml/8deef7c4-ac75-4db8-91b7-02cf0e39e371@roeck-us.net/
> Fixes: 7704e6be4ed2 ("mei: hook mei_device on class device")
> Signed-off-by: Alexander Usyskin
I also confirm this patch fixes the issue:
Tested-by: Marek Marczykowski-Górecki
> ---
> drivers/misc/mei/pci-me.c | 13 ++++++-------
> drivers/misc/mei/pci-txe.c | 13 ++++++-------
> drivers/misc/mei/platform-vsc.c | 11 +++++------
> 3 files changed, 17 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/misc/mei/pci-me.c b/drivers/misc/mei/pci-me.c
> index b017ff29dbd1..73cad914be9f 100644
> --- a/drivers/misc/mei/pci-me.c
> +++ b/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;
> diff --git a/drivers/misc/mei/pci-txe.c b/drivers/misc/mei/pci-txe.c
> index 06b55a891c6b..98d1bc2c7f4b 100644
> --- a/drivers/misc/mei/pci-txe.c
> +++ b/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;
> diff --git a/drivers/misc/mei/platform-vsc.c b/drivers/misc/mei/platform-vsc.c
> index 288e7b72e942..9787b9cee71c 100644
> --- a/drivers/misc/mei/platform-vsc.c
> +++ b/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;
> }
>
> --
> 2.43.0
>
--
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab