From: Dave Jiang <dave.jiang@xxxxxxxxx> [ Upstream commit 66903461ffed0b66fc3e0200082d4e09365aacdc ] Block wq_max_batch_size_store() when the device is configured as read-only and not configurable. Fixes: e7184b159dd3 ("dmaengine: idxd: add support for configurable max wq batch 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/164971493551.2201159.1942042593642155209.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 7e19ab92b61a..6c41d429bd89 100644 --- a/drivers/dma/idxd/sysfs.c +++ b/drivers/dma/idxd/sysfs.c @@ -939,6 +939,9 @@ static ssize_t wq_max_batch_size_store(struct device *dev, struct device_attribu u64 batch_size; int rc; + if (!test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags)) + return -EPERM; + if (wq->state != IDXD_WQ_DISABLED) return -EPERM; -- 2.35.1