ux500_busy_complete() can queue ux500_busy_timeout_work for an R1b
command, but mmci_remove() never cancels it. The work can subsequently
dereference the devm-allocated mmci_host after it has been released.

Mask the controller interrupts and disable the delayed work during
removal. This drains any queued instance and stops an IRQ handler that
is still in progress from queueing the work again once it has been
disabled.

This issue was found by an in-house static analysis tool.

Fixes: b1a665932dc2 ("mmc: mmci: Add support for SW busy-end timeouts")
Cc: stable@vger.kernel.org # v6.10+
Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>
---
 drivers/mmc/host/mmci.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index e500051bd..416bdb184 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -2511,6 +2511,9 @@ static void mmci_remove(struct amba_device *dev)
 		writel(0, host->base + MMCICOMMAND);
 		writel(0, host->base + MMCIDATACTRL);
 
+		if (variant->busy_detect)
+			disable_delayed_work_sync(&host->ux500_busy_timeout_work);
+
 		mmci_dma_release(host);
 		clk_disable_unprepare(host->clk);
 	}

On Fri, Aug 14, 2026 at 10:25 AM Fan Wu <fanwu01@zju.edu.cn> wrote:
>
> ux500_busy_complete() can queue ux500_busy_timeout_work for an R1b
> command, but mmci_remove() never cancels it. The work can subsequently
> dereference the devm-allocated mmci_host after it has been released.
>
> Mask the controller interrupts and disable the delayed work during
> removal. This drains any queued instance and stops an IRQ handler that
> is still in progress from queueing the work again once it has been
> disabled.
>
> This issue was found by an in-house static analysis tool.
>
> Fixes: b1a665932dc2 ("mmc: mmci: Add support for SW busy-end timeouts")
> Cc: stable@vger.kernel.org # v6.10+
> Assisted-by: Codex:gpt-5.6
> Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>

Applied for fixes, thanks!

Kind regards
Uffe


> ---
>  drivers/mmc/host/mmci.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
> index e500051bd..416bdb184 100644
> --- a/drivers/mmc/host/mmci.c
> +++ b/drivers/mmc/host/mmci.c
> @@ -2511,6 +2511,9 @@ static void mmci_remove(struct amba_device *dev)
>                 writel(0, host->base + MMCICOMMAND);
>                 writel(0, host->base + MMCIDATACTRL);
>
> +               if (variant->busy_detect)
> +                       disable_delayed_work_sync(&host->ux500_busy_timeout_work);
> +
>                 mmci_dma_release(host);
>                 clk_disable_unprepare(host->clk);
>         }

On Fri, Aug 14, 2026 at 10:27 AM Fan Wu <fanwu01@zju.edu.cn> wrote:

> ux500_busy_complete() can queue ux500_busy_timeout_work for an R1b
> command, but mmci_remove() never cancels it. The work can subsequently
> dereference the devm-allocated mmci_host after it has been released.
>
> Mask the controller interrupts and disable the delayed work during
> removal. This drains any queued instance and stops an IRQ handler that
> is still in progress from queueing the work again once it has been
> disabled.
>
> This issue was found by an in-house static analysis tool.
>
> Fixes: b1a665932dc2 ("mmc: mmci: Add support for SW busy-end timeouts")
> Cc: stable@vger.kernel.org # v6.10+
> Assisted-by: Codex:gpt-5.6
> Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>

Reviewed-by: Linus Walleij <linusw@kernel.org>

Yours,
Linus Walleij