From: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx> [ Upstream commit 6ca2738174e4ee44edb2ab2d86ce74f015a0cc32 ] Bus cleanup path in DMA mode may trigger a RING_OP_STAT interrupt when the ring is being stopped. Depending on timing between ring stop request completion, interrupt handler removal and code execution this may lead to a NULL pointer dereference in hci_dma_irq_handler() if it gets to run after the io_data pointer is set to NULL in hci_dma_cleanup(). Prevent this my masking the ring interrupts before ring stop request. Signed-off-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20240920144432.62370-2-jarkko.nikula@xxxxxxxxxxxxxxx Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/i3c/master/mipi-i3c-hci/dma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c index edc3a69bfe31f..bcc0c7d4131f2 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -174,10 +174,10 @@ static void hci_dma_cleanup(struct i3c_hci *hci) for (i = 0; i < rings->total; i++) { rh = &rings->headers[i]; + rh_reg_write(INTR_SIGNAL_ENABLE, 0); rh_reg_write(RING_CONTROL, 0); rh_reg_write(CR_SETUP, 0); rh_reg_write(IBI_SETUP, 0); - rh_reg_write(INTR_SIGNAL_ENABLE, 0); if (rh->xfer) dma_free_coherent(&hci->master.dev, -- 2.43.0
