Am 14.07.21 um 16:54 schrieb Zheyu Ma:

When calling ttm_range_man_fini(), 'man' may be uninitialized, which may cause a null pointer dereference bug.

Fix this by checking if it is a null pointer.

It would be better if the driver doesn't try to fini a manager which was never initialized, but for now that should work.

This log reveals it:

[ 7.902580 ] BUG: kernel NULL pointer dereference, address: 0000000000000058 [ 7.905721 ] RIP: 0010:ttm_range_man_fini+0x40/0x160 [ 7.911826 ] Call Trace: [ 7.911826 ] radeon_ttm_fini+0x167/0x210 [ 7.911826 ] radeon_bo_fini+0x15/0x40 [ 7.913767 ] rs400_fini+0x55/0x80 [ 7.914358 ] radeon_device_fini+0x3c/0x140 [ 7.914358 ] radeon_driver_unload_kms+0x5c/0xe0 [ 7.914358 ] radeon_driver_load_kms+0x13a/0x200 [ 7.914358 ] ? radeon_driver_unload_kms+0xe0/0xe0 [ 7.914358 ] drm_dev_register+0x1db/0x290 [ 7.914358 ] radeon_pci_probe+0x16a/0x230 [ 7.914358 ] local_pci_probe+0x4a/0xb0

Signed-off-by: Zheyu Ma zheyuma97@gmail.com

Reviewed-by: Christian König christian.koenig@amd.com

Going to push it later.

Thanks, Christian.

---

drivers/gpu/drm/ttm/ttm_range_manager.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/ttm/ttm_range_manager.c b/drivers/gpu/drm/ttm/ttm_range_manager.c index 03395386e8a7..f4b08a8705b3 100644 --- a/drivers/gpu/drm/ttm/ttm_range_manager.c +++ b/drivers/gpu/drm/ttm/ttm_range_manager.c @@ -181,6 +181,9 @@ int ttm_range_man_fini(struct ttm_device *bdev, struct drm_mm *mm = &rman->mm; int ret;

• if (!man)

• return 0;
  

• ttm_resource_manager_set_used(man, false);

  ret = ttm_resource_manager_evict_all(bdev, man);