[PATCH v2] dpf: fix UAF and double free in idpf_plug_vport_aux_dev() error path

Guangshuo Li
2026-04-13T11:20:48Z

If auxiliary_device_add() fails, idpf_plug_vport_aux_dev() calls
auxiliary_device_uninit(adev), whose release callback
idpf_vport_adev_release() frees the containing
struct iidc_rdma_vport_auxiliary_dev.

The current error path then accesses adev->id and later frees iadev
again, which may lead to a use-after-free and double free.

The issue was identified by a static analysis tool I developed and
confirmed by manual review.

Fix it by storing the allocated auxiliary device id in a local
variable and avoiding direct freeing of iadev after
auxiliary_device_uninit().

Fixes: be91128c579c ("idpf: implement RDMA vport auxiliary dev create, init, and destroy")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
v2:
- note that the issue was identified by my static analysis tool
- and confirmed by manual review

drivers/net/ethernet/intel/idpf/idpf_idc.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/idpf/idpf_idc.c b/drivers/net/ethernet/intel/idpf/idpf_idc.c
index 6dad0593f7f2..2a18907643fc 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_idc.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_idc.c
@@ -59,6 +59,7 @@ static int idpf_plug_vport_aux_dev(struct iidc_rdma_core_dev_info *cdev_info,
char name[IDPF_IDC_MAX_ADEV_NAME_LEN];
struct auxiliary_device *adev;
int ret;
+ int adev_id;

iadev = kzalloc(sizeof(*iadev), GFP_KERNEL);
if (!iadev)
@@ -74,11 +75,14 @@ static int idpf_plug_vport_aux_dev(struct iidc_rdma_core_dev_info *cdev_info,
goto err_ida_alloc;
}
adev->id = ret;
+ adev->id = adev_id;
adev->dev.release = idpf_vport_adev_release;
adev->dev.parent = &cdev_info->pdev->dev;
sprintf(name, "%04x.rdma.vdev", cdev_info->pdev->vendor);
adev->name = name;

+ /* iadev is owned by the auxiliary device */
+ iadev = NULL;
ret = auxiliary_device_init(adev);
if (ret)
goto err_aux_dev_init;
@@ -92,7 +96,7 @@ static int idpf_plug_vport_aux_dev(struct iidc_rdma_core_dev_info *cdev_info,
err_aux_dev_add:
auxiliary_device_uninit(adev);
err_aux_dev_init:
- ida_free(&idpf_idc_ida, adev->id);
+ ida_free(&idpf_idc_ida, adev_id);
err_ida_alloc:
vdev_info->adev = NULL;
kfree(iadev);
--
2.43.0