[PATCH v4 2/3] drm/xe/nvm: Fix double-free on aux add failure

[Shuicheng Lin <shuicheng.lin@intel.com>]

After a successful auxiliary_device_init(), aux_dev->dev.release
(xe_nvm_release_dev()) is responsible for the kfree(nvm). When
there is failure with auxiliary_device_add(), driver will call
auxiliary_device_uninit(), which call put_device(). So that the
.release callback will be triggered to free the memory associated
with the auxiliary_device.

Move the kfree(nvm) into the auxiliary_device_init() failure path
and remove the err goto path to fix below error.

"
[   13.232905] ==================================================================
[   13.232911] BUG: KASAN: double-free in xe_nvm_init+0x751/0xf10 [xe]
[   13.233112] Free of addr ffff888120635000 by task systemd-udevd/273

[   13.233120] CPU: 8 UID: 0 PID: 273 Comm: systemd-udevd Not tainted 6.19.0-rc2-lgci-xe-kernel+ #225 PREEMPT(voluntary)
...
[   13.233125] Call Trace:
[   13.233126]  <TASK>
[   13.233127]  dump_stack_lvl+0x7f/0xc0
[   13.233132]  print_report+0xce/0x610
[   13.233136]  ? kasan_complete_mode_report_info+0x5d/0x1e0
[   13.233139]  ? xe_nvm_init+0x751/0xf10 [xe]
...
"

v2: drop err goto path. (Alexander)

Fixes: d4c3ed963e41 ("drm/xe: defer free of NVM auxiliary container to device release callback")
Reviewed-by: Nitin Gote <nitin.r.gote@intel.com>
Reviewed-by: Brian Nguyen <brian3.nguyen@intel.com>
Cc: Alexander Usyskin <alexander.usyskin@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Suggested-by: Brian Nguyen <brian3.nguyen@intel.com>
Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com>
---
 drivers/gpu/drm/xe/xe_nvm.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_nvm.c b/drivers/gpu/drm/xe/xe_nvm.c
index 77856f460770..6f9dd519371c 100644
--- a/drivers/gpu/drm/xe/xe_nvm.c
+++ b/drivers/gpu/drm/xe/xe_nvm.c
@@ -164,19 +164,17 @@ int xe_nvm_init(struct xe_device *xe)
 	ret = auxiliary_device_init(aux_dev);
 	if (ret) {
 		drm_err(&xe->drm, "xe-nvm aux init failed %d\n", ret);
-		goto err;
+		kfree(nvm);
+		xe->nvm = NULL;
+		return ret;
 	}
 
 	ret = auxiliary_device_add(aux_dev);
 	if (ret) {
 		drm_err(&xe->drm, "xe-nvm aux add failed %d\n", ret);
 		auxiliary_device_uninit(aux_dev);
-		goto err;
+		xe->nvm = NULL;
+		return ret;
 	}
 	return devm_add_action_or_reset(xe->drm.dev, xe_nvm_fini, xe);
-
-err:
-	kfree(nvm);
-	xe->nvm = NULL;
-	return ret;
 }
-- 
2.50.1