diff options
| author | Yuho Choi <dbgh9129@gmail.com> | 2026-05-25 10:15:50 -0400 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2026-07-02 20:49:54 +0530 |
| commit | ee1d7274102285d78a53161fc705a8d8cd40b066 (patch) | |
| tree | c27db91076c71c6f7b112bb4a4793369779e591f /drivers/dma/idxd | |
| parent | ec2d428b2e32dd157de8f86a86dd85c5b2c8f45c (diff) | |
dmaengine: idxd: fix fdev setup failure cleanup in idxd_cdev_open()
The failed_dev_add and failed_dev_name paths drop the file-device
reference while wq->wq_lock is still held. If put_device(fdev) drops the
last reference, idxd_file_dev_release() runs synchronously and tries to
take wq->wq_lock again, deadlocking.
Those paths also fall through into the later ctx cleanup labels even
though idxd_file_dev_release() owns that cleanup and frees ctx. This can
make idxd_xa_pasid_remove(ctx) and kfree(ctx) operate on a freed context.
Move idxd_wq_get() before file-device setup can fail, since the release
callback always calls idxd_wq_put(). Then unlock wq->wq_lock before
put_device(fdev) and return directly from the file-device setup failure
path, leaving ctx cleanup to the release callback.
Fixes: e6fd6d7e5f0fe ("dmaengine: idxd: add a device to represent the file opened")
Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Link: https://patch.msgid.link/20260525141550.1385581-1-dbgh9129@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma/idxd')
| -rw-r--r-- | drivers/dma/idxd/cdev.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c index 0366c7cf3502..82b07cf942ef 100644 --- a/drivers/dma/idxd/cdev.c +++ b/drivers/dma/idxd/cdev.c @@ -288,6 +288,7 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) fdev->parent = cdev_dev(idxd_cdev); 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) { @@ -301,13 +302,14 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) goto failed_dev_add; } - idxd_wq_get(wq); mutex_unlock(&wq->wq_lock); return 0; failed_dev_add: failed_dev_name: + mutex_unlock(&wq->wq_lock); put_device(fdev); + return rc; failed_ida: failed_set_pasid: if (device_user_pasid_enabled(idxd)) |