4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Dan Williams <dan.j.williams@xxxxxxxxx>
[ Upstream commit 8b06b884cd98f7ec8b5028680b99fabfb7b3e192 ]
Keep the nfit_test instances alive until after nfit_test_teardown(), as
we may be doing resource lookups until the final un-registrations have
completed. This fixes crashes of the form.
BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
IP: __release_resource+0x12/0x90
Call Trace:
remove_resource+0x23/0x40
__wrap_remove_resource+0x29/0x30 [nfit_test_iomap]
acpi_nfit_remove_resource+0xe/0x10 [nfit]
devm_action_release+0xf/0x20
release_nodes+0x16d/0x2b0
devres_release_all+0x3c/0x60
device_release+0x21/0x90
kobject_release+0x6a/0x170
kobject_put+0x2f/0x60
put_device+0x17/0x20
platform_device_unregister+0x20/0x30
nfit_test_exit+0x36/0x960 [nfit_test]
Reported-by: Linda Knippers <linda.knippers@xxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/testing/nvdimm/test/nfit.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
--- a/tools/testing/nvdimm/test/nfit.c
+++ b/tools/testing/nvdimm/test/nfit.c
@@ -1908,6 +1908,7 @@ static __init int nfit_test_init(void)
put_device(&pdev->dev);
goto err_register;
}
+ get_device(&pdev->dev);
rc = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
if (rc)
@@ -1926,6 +1927,10 @@ static __init int nfit_test_init(void)
if (instances[i])
platform_device_unregister(&instances[i]->pdev);
nfit_test_teardown();
+ for (i = 0; i < NUM_NFITS; i++)
+ if (instances[i])
+ put_device(&instances[i]->pdev.dev);
+
return rc;
}
@@ -1933,10 +1938,13 @@ static __exit void nfit_test_exit(void)
{
int i;
- platform_driver_unregister(&nfit_test_driver);
for (i = 0; i < NUM_NFITS; i++)
platform_device_unregister(&instances[i]->pdev);
+ platform_driver_unregister(&nfit_test_driver);
nfit_test_teardown();
+
+ for (i = 0; i < NUM_NFITS; i++)
+ put_device(&instances[i]->pdev.dev);
class_destroy(nfit_test_dimm);
}