[PATCH 4.12 080/196] tools/testing/nvdimm: fix nfit_test buffer overflow

[Greg Kroah-Hartman]

4.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Yasunori Goto <y-goto@xxxxxxxxxxxxxx>

commit a117699c6c4a4b1b4e90ed51e393590986567cb4 upstream.

The root cause of panic is the num_pm of nfit_test1 is wrong.
Though 1 is specified for num_pm at nfit_test_init(), it must be 2,
because nfit_test1->spa_set[] array has 2 elements.

Since the array is smaller than expected, the driver breaks other area.
(it is often the link list of devres).

As a result, panic occurs like the following example.

    CPU: 4 PID: 2233 Comm: lt-libndctl Tainted: G           O    4.12.0-rc1+ #12
    RIP: 0010:__list_del_entry_valid+0x6c/0xa0
    Call Trace:
     release_nodes+0x76/0x260
     devres_release_all+0x3c/0x50
     device_release_driver_internal+0x159/0x200
     device_release_driver+0x12/0x20
     bus_remove_device+0xfd/0x170
     device_del+0x1e8/0x330
     platform_device_del+0x28/0x90
     platform_device_unregister+0x12/0x30
     nfit_test_exit+0x2a/0x93b [nfit_test]

Signed-off-by: Yasunori Goto <y-goto@xxxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 tools/testing/nvdimm/test/nfit.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/testing/nvdimm/test/nfit.c
+++ b/tools/testing/nvdimm/test/nfit.c
@@ -1943,7 +1943,7 @@ static __init int nfit_test_init(void)
 			nfit_test->setup = nfit_test0_setup;
 			break;
 		case 1:
-			nfit_test->num_pm = 1;
+			nfit_test->num_pm = 2;
 			nfit_test->dcr_idx = NUM_DCR;
 			nfit_test->num_dcr = 2;
 			nfit_test->alloc = nfit_test1_alloc;