This is a note to let you know that I've just added the patch titled tools/testing/nvdimm: fix nfit_test shutdown crash to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tools-testing-nvdimm-fix-nfit_test-shutdown-crash.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Thu Mar 22 14:40:23 CET 2018 From: Dan Williams <dan.j.williams@xxxxxxxxx> Date: Thu, 13 Apr 2017 23:14:34 -0700 Subject: tools/testing/nvdimm: fix nfit_test shutdown crash 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); } Patches currently in stable-queue which might be from dan.j.williams@xxxxxxxxx are queue-4.9/tools-testing-nvdimm-fix-nfit_test-shutdown-crash.patch