From: Toshi Kani <toshi.kani@hpe.com>
Date: Fri, 2 Feb 2018 21:00:36 +0000 (-0700)
Subject: acpi, nfit: fix register dimm error handling
X-Git-Tag: v4.14.20~10
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9fc03876355ac0bbbb774d15a362e35805c9db85;p=platform%2Fkernel%2Flinux-rpi.git

acpi, nfit: fix register dimm error handling

commit 23fbd7c70aec7600e3227eb24259fc55bf6e4881 upstream.

A NULL pointer reference kernel bug was observed when
acpi_nfit_add_dimm() called in acpi_nfit_register_dimms() failed. This
error path does not set nfit_mem->nvdimm, but the 2nd
list_for_each_entry() loop in the function assumes it's always set. Add
a check to nfit_mem->nvdimm.

Fixes: ba9c8dd3c222 ("acpi, nfit: add dimm device notification support")
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index dea0fb3..f14b432 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -1618,6 +1618,9 @@ static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
 		struct kernfs_node *nfit_kernfs;
 
 		nvdimm = nfit_mem->nvdimm;
+		if (!nvdimm)
+			continue;
+
 		nfit_kernfs = sysfs_get_dirent(nvdimm_kobj(nvdimm)->sd, "nfit");
 		if (nfit_kernfs)
 			nfit_mem->flags_attr = sysfs_get_dirent(nfit_kernfs,