This is a note to let you know that I've just added the patch titled dmaengine: idxd: add RO check for wq max_transfer_size write to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: dmaengine-idxd-add-ro-check-for-wq-max_transfer_size.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit f545f91b80a19077dd6e9be58c30be2e5d0382b0 Author: Dave Jiang <dave.jiang@xxxxxxxxx> Date: Mon Apr 11 15:08:01 2022 -0700 dmaengine: idxd: add RO check for wq max_transfer_size write [ 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> diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c index f7ab5c077a2b..33d94c67fedb 100644 --- a/drivers/dma/idxd/sysfs.c +++ b/drivers/dma/idxd/sysfs.c @@ -842,6 +842,9 @@ 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;