[PATCH net] idpf: fix double free and use-after-free in aux device error paths

[PATCH net] idpf: fix double free and use-after-free in aux device error paths

[Greg Kroah-Hartman]

When auxiliary_device_add() fails in idpf_plug_vport_aux_dev() or
idpf_plug_core_aux_dev(), the err_aux_dev_add label calls
auxiliary_device_uninit() and falls through to err_aux_dev_init.  The
uninit call will trigger put_device(), which invokes the release
callback (idpf_vport_adev_release / idpf_core_adev_release) that frees
iadev.  The fall-through then reads adev->id from the freed iadev for
ida_free() and double-frees iadev with kfree().

Free the IDA slot and clear the back-pointer before uninit, while adev
is still valid, then return immediately.

Commit 65637c3a1811 65637c3a1811 ("idpf: fix UAF in RDMA core aux dev
deinitialization") fixed the same use-after-free in the matching unplug
path in this file but missed both probe error paths.

Cc: Tony Nguyen <anthony.l.nguyen@intel.com>
Cc: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: stable <stable@kernel.org>
Fixes: be91128c579c ("idpf: implement RDMA vport auxiliary dev create, init, and destroy")
Fixes: f4312e6bfa2a ("idpf: implement core RDMA auxiliary dev create, init, and destroy")
Assisted-by: gregkh_clanker_t1000
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
Note, these cleanup paths are messy, but I couldn't see a simpler way
without a lot more rework, so I choose the simple way :)

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

diff --git a/drivers/net/ethernet/intel/idpf/idpf_idc.c b/drivers/net/ethernet/intel/idpf/idpf_idc.c
index 7e4f4ac92653..b7d6b08fc89e 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_idc.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_idc.c
@@ -90,7 +90,10 @@ static int idpf_plug_vport_aux_dev(struct iidc_rdma_core_dev_info *cdev_info,
 	return 0;
 
 err_aux_dev_add:
+	ida_free(&idpf_idc_ida, adev->id);
+	vdev_info->adev = NULL;
 	auxiliary_device_uninit(adev);
+	return ret;
 err_aux_dev_init:
 	ida_free(&idpf_idc_ida, adev->id);
 err_ida_alloc:
@@ -228,7 +231,10 @@ static int idpf_plug_core_aux_dev(struct iidc_rdma_core_dev_info *cdev_info)
 	return 0;
 
 err_aux_dev_add:
+	ida_free(&idpf_idc_ida, adev->id);
+	cdev_info->adev = NULL;
 	auxiliary_device_uninit(adev);
+	return ret;
 err_aux_dev_init:
 	ida_free(&idpf_idc_ida, adev->id);
 err_ida_alloc:
-- 
2.53.0