From: Dave Jiang <dave.jiang@xxxxxxxxx> [ Upstream commit 505a2d1032ae656b0a8c736be110255503941cde ] Block wq_max_transfer_size_store() when the device is configured as read-only and not configurable. Fixes: d7aad5550eca ("dmaengine: idxd: add support for configurable max wq xfer size") Reported-by: Bernice Zhang <bernice.zhang@xxxxxxxxx> Tested-by: Bernice Zhang <bernice.zhang@xxxxxxxxx> Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx> Link: https://lore.kernel.org/r/164971488154.2200913.10706665404118545941.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/dma/idxd/sysfs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c index 5bf4b4be64e4..51af0dfc3c63 100644 --- a/drivers/dma/idxd/sysfs.c +++ b/drivers/dma/idxd/sysfs.c @@ -1098,6 +1098,9 @@ static ssize_t wq_max_transfer_size_store(struct device *dev, struct device_attr u64 xfer_size; int rc; + if (!test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags)) + return -EPERM; + if (wq->state != IDXD_WQ_DISABLED) return -EPERM; -- 2.35.1