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If this is the last reference, put_device(fdev) runs idxd_file_dev_release(), which takes wq->wq_lock again and deadlocks. Those error paths also fall through into the later ctx cleanup labels after idxd_file_dev_release() has already freed ctx. This can make idxd_xa_pasid_remove(ctx) operate on freed memory and can later free ctx again at the failed label. Use scoped put_device() cleanup for fdev and return from the fdev setup failure path after unlocking wq->wq_lock. Take the WQ reference before fdev can be released so idxd_file_dev_release() always balances a matching idxd_wq_get(). Fixes: e6fd6d7e5f0fe ("dmaengine: idxd: add a device to represent the file opened") Signed-off-by: Yuho Choi --- Changes in v2: - Use __free(put_device) for the file-device reference. - Take the WQ reference before fdev can be released so the release callback's idxd_wq_put() has a matching idxd_wq_get(). drivers/dma/idxd/cdev.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c index 0366c7cf3502..18ff29118d12 100644 --- a/drivers/dma/idxd/cdev.c +++ b/drivers/dma/idxd/cdev.c @@ -216,7 +216,7 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) struct idxd_user_context *ctx; struct idxd_device *idxd; struct idxd_wq *wq; - struct device *dev, *fdev; + struct device *dev, *fdev __free(put_device) = NULL; int rc = 0; struct iommu_sva *sva = NULL; unsigned int pasid; @@ -289,6 +289,7 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) fdev->bus = &dsa_bus_type; fdev->type = &idxd_cdev_file_type; + idxd_wq_get(wq); rc = dev_set_name(fdev, "file%d", ctx->id); if (rc < 0) { dev_warn(dev, "set name failure\n"); @@ -301,13 +302,14 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) goto failed_dev_add; } - idxd_wq_get(wq); + fdev = NULL; mutex_unlock(&wq->wq_lock); return 0; failed_dev_add: failed_dev_name: - put_device(fdev); + mutex_unlock(&wq->wq_lock); + return rc; failed_ida: failed_set_pasid: if (device_user_pasid_enabled(idxd)) -- 2.43.0