[PATCH v1 4/5] dmaengine: idxd: fix memory leak in error handling path of idxd_alloc

From: Shuai Xue
Date: Fri Jan 10 2025 - 03:24:03 EST


Memory allocated for idxd is not freed if an error occurs during
idxd_alloc(). To fix it, free the allocated memory in the reverse order
of allocation before exiting the function in case of an error.

Signed-off-by: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>
---
drivers/dma/idxd/init.c | 24 +++++++++++++++---------
1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index 04a7d7706e53..f0e3244d630d 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -565,28 +565,34 @@ static struct idxd_device *idxd_alloc(struct pci_dev *pdev, struct idxd_driver_d
idxd_dev_set_type(&idxd->idxd_dev, idxd->data->type);
idxd->id = ida_alloc(&idxd_ida, GFP_KERNEL);
if (idxd->id < 0)
- return NULL;
+ goto err_ida;

idxd->opcap_bmap = bitmap_zalloc_node(IDXD_MAX_OPCAP_BITS, GFP_KERNEL, dev_to_node(dev));
- if (!idxd->opcap_bmap) {
- ida_free(&idxd_ida, idxd->id);
- return NULL;
- }
+ if (!idxd->opcap_bmap)
+ goto err_opcap;

device_initialize(conf_dev);
conf_dev->parent = dev;
conf_dev->bus = &dsa_bus_type;
conf_dev->type = idxd->data->dev_type;
rc = dev_set_name(conf_dev, "%s%d", idxd->data->name_prefix, idxd->id);
- if (rc < 0) {
- put_device(conf_dev);
- return NULL;
- }
+ if (rc < 0)
+ goto err_name;

spin_lock_init(&idxd->dev_lock);
spin_lock_init(&idxd->cmd_lock);

return idxd;
+
+err_name:
+ put_device(conf_dev);
+ bitmap_free(idxd->opcap_bmap);
+err_opcap:
+ ida_free(&idxd_ida, idxd->id);
+err_ida:
+ kfree(idxd);
+
+ return NULL;
}

static int idxd_enable_system_pasid(struct idxd_device *idxd)
--
2.39.3