[PATCH] dmaengine: idxd: Fix passing freed memory in idxd_cdev_open()

From: Harshit Mogalapalli
Date: Tue May 09 2023 - 02:07:34 EST


Smatch warns:
drivers/dma/idxd/cdev.c:327:
idxd_cdev_open() warn: 'sva' was already freed.

When idxd_wq_set_pasid() fails, the current code unbinds sva and then
goes to 'failed_set_pasid' where iommu_sva_unbind_device is called
again causing the above warning.
[ device_user_pasid_enabled(idxd) is still true when calling
failed_set_pasid ]

Fix this by removing additional unbind when idxd_wq_set_pasid() fails

Fixes: b022f59725f0 ("dmaengine: idxd: add idxd_copy_cr() to copy user completion record during page fault handling")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx>
---
This is purely based on static analysis. Only compile tested.
---
drivers/dma/idxd/cdev.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c
index ecbf67c2ad2b..d32deb9b4e3d 100644
--- a/drivers/dma/idxd/cdev.c
+++ b/drivers/dma/idxd/cdev.c
@@ -277,7 +277,6 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp)
if (wq_dedicated(wq)) {
rc = idxd_wq_set_pasid(wq, pasid);
if (rc < 0) {
- iommu_sva_unbind_device(sva);
dev_err(dev, "wq set pasid failed: %d\n", rc);
goto failed_set_pasid;
}
--
2.38.1