[PATCH] libnvdimm: Add a NULL entry to 'nvdimm_firmware_attributes'

We recently discovered a kernel oops with 'papr_scm' module while booting ppc64 phyp guest with following back-trace: BUG: Kernel NULL pointer dereference on write at 0x00000188 Faulting instruction address: 0xc0000000005d7084 Oops: Kernel access of bad area, sig: 11 [#1] <snip> Call Trace: internal_create_group+0x128/0x4c0 (unreliable) internal_create_groups.part.4+0x70/0x130 device_add+0x458/0x9c0 nd_async_device_register+0x28/0xa0 [libnvdimm] async_run_entry_fn+0x78/0x1f0 process_one_work+0x2c0/0x5b0 worker_thread+0x88/0x650 kthread+0x1a8/0x1b0 ret_from_kernel_thread+0x5c/0x6c A bisect lead to the 'commit 48001ea50d17f ("PM, libnvdimm: Add runtime firmware activation support")' and on investigation discovered that the newly introduced 'struct attribute *nvdimm_firmware_attributes[]' is missing a terminating NULL entry in the array. This causes a loop in sysfs's 'create_files()' to read garbage beyond bounds of 'nvdimm_firmware_attributes' and trigger the oops. Fixes: 48001ea50d17f ("PM, libnvdimm: Add runtime firmware activation support") Reported-by: Sandipan Das <sandipan(a)linux.ibm.com&gt; Signed-off-by: Vaibhav Jain <vaibhav(a)linux.ibm.com&gt; --- drivers/nvdimm/dimm_devs.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c index 61374def51555..b59032e0859b7 100644 --- a/drivers/nvdimm/dimm_devs.c +++ b/drivers/nvdimm/dimm_devs.c @@ -529,6 +529,7 @@ static DEVICE_ATTR_ADMIN_RW(activate); static struct attribute *nvdimm_firmware_attributes[] = { &dev_attr_activate.attr, &dev_attr_result.attr, + NULL, }; static umode_t nvdimm_firmware_visible(struct kobject *kobj, struct attribute *a, int n) -- 2.26.2