From: Sergey Senozhatsky Date: Tue, 28 Apr 2026 02:55:44 +0000 (+0900) Subject: mailbox: mtk-adsp: fix UAF during device teardown X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=b57d1a40bc43258372fa1f4d39305e093947a262;p=thirdparty%2Fkernel%2Flinux.git mailbox: mtk-adsp: fix UAF during device teardown When the SOF audio driver fails to initialize (e.g. firmware boot timeout), its devres unwind frees the snd_sof_dev object that the mailbox client (mtk-adsp-ipc) reaches via chan->cl->rx_callback. The mtk-adsp-mailbox shutdown clears the mailbox command registers but leaves the IRQ line unmasked, so a late interrupt can still queue a threaded handler after mbox_free_channel() had cleared chan->cl, and mbox_chan_received_data() would then trigger UAF: BUG: KASAN: slab-use-after-free in sof_ipc3_validate_fw_version sof_ipc3_validate_fw_version sof_ipc3_do_rx_work sof_ipc3_rx_msg mt8196_dsp_handle_request mtk_adsp_ipc_recv mbox_chan_received_data mtk_adsp_mbox_isr irq_thread_fn Freed by task ...: kfree devres_release_all really_probe ... (sof-audio-of-mt8196 probe failure) The crash was observed roughly three seconds after the failed probe. disable_irq() in shutdown and enable_irq() in startup. disable_irq() also waits for any in-flight interrupts, so by the time mbox_free_channel() proceeds to clear chan->cl no rx_callback can run. In addition, request the IRQ with IRQF_NO_AUTOEN so it stays masked between probe and the first client bind — otherwise an early interrupt can crash on chan->cl == NULL in mbox_chan_received_data(). Fixes: af2dfa96c52d ("mailbox: mediatek: add support for adsp mailbox controller") Signed-off-by: Sergey Senozhatsky Reviewed-by: Tzung-Bi Shih Signed-off-by: Jassi Brar --- diff --git a/drivers/mailbox/mtk-adsp-mailbox.c b/drivers/mailbox/mtk-adsp-mailbox.c index 91487aa4d7da0..8bcecddee0eb5 100644 --- a/drivers/mailbox/mtk-adsp-mailbox.c +++ b/drivers/mailbox/mtk-adsp-mailbox.c @@ -19,6 +19,7 @@ struct mtk_adsp_mbox_priv { struct mbox_controller mbox; void __iomem *va_mboxreg; const struct mtk_adsp_mbox_cfg *cfg; + int irq; }; struct mtk_adsp_mbox_cfg { @@ -67,6 +68,8 @@ static int mtk_adsp_mbox_startup(struct mbox_chan *chan) writel(0xFFFFFFFF, priv->va_mboxreg + priv->cfg->clr_in); writel(0xFFFFFFFF, priv->va_mboxreg + priv->cfg->clr_out); + enable_irq(priv->irq); + return 0; } @@ -74,6 +77,8 @@ static void mtk_adsp_mbox_shutdown(struct mbox_chan *chan) { struct mtk_adsp_mbox_priv *priv = get_mtk_adsp_mbox_priv(chan->mbox); + disable_irq(priv->irq); + /* Clear ADSP mbox command */ writel(0xFFFFFFFF, priv->va_mboxreg + priv->cfg->clr_in); writel(0xFFFFFFFF, priv->va_mboxreg + priv->cfg->clr_out); @@ -139,8 +144,10 @@ static int mtk_adsp_mbox_probe(struct platform_device *pdev) if (irq < 0) return irq; + priv->irq = irq; ret = devm_request_threaded_irq(dev, irq, mtk_adsp_mbox_irq, - mtk_adsp_mbox_isr, IRQF_TRIGGER_NONE, + mtk_adsp_mbox_isr, + IRQF_TRIGGER_NONE | IRQF_NO_AUTOEN, dev_name(dev), mbox->chans); if (ret < 0) return ret;