libnvdimm v5.0-rc4

* Fix support for NVDIMMs that implement the ACPI standard label
   methods.
 * Fix error handling for security overwrite (memory leak / userspace
   hang condition), and another one-line security cleanup
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Merge tag 'libnvdimm-fixes-5.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm fixes from Dan Williams:
 "A fix for namespace label support for non-Intel NVDIMMs that implement
  the ACPI standard label method.

  This has apparently never worked and could wait for v5.1. However it
  has enough visibility with hardware vendors [1] and distro bug
  trackers [2], and low enough risk that I decided it should go in for
  -rc4. The other fixups target the new, for v5.0, nvdimm security
  functionality. The larger init path fixup closes a memory leak and a
  potential userspace lockup due to missed notifications.

    [1] https://github.com/pmem/ndctl/issues/78
    [2] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1811785

  These have all soaked in -next for a week with no reported issues.

  Summary:

   - Fix support for NVDIMMs that implement the ACPI standard label
     methods.

   - Fix error handling for security overwrite (memory leak / userspace
     hang condition), and another one-line security cleanup"

* tag 'libnvdimm-fixes-5.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  acpi/nfit: Fix command-supported detection
  acpi/nfit: Block function zero DSMs
  libnvdimm/security: Require nvdimm_security_setup_events() to succeed
  nfit_test: fix security state pull for nvdimm security nfit_test

drivers/acpi/nfit/core.c

@@ -409,6 +409,32 @@ static bool payload_dumpable(struct nvdimm *nvdimm, unsigned int func)
 	return true;
 }
 
+static int cmd_to_func(struct nfit_mem *nfit_mem, unsigned int cmd,
+		struct nd_cmd_pkg *call_pkg)
+{
+	if (call_pkg) {
+		int i;
+
+		if (nfit_mem->family != call_pkg->nd_family)
+			return -ENOTTY;
+
+		for (i = 0; i < ARRAY_SIZE(call_pkg->nd_reserved2); i++)
+			if (call_pkg->nd_reserved2[i])
+				return -EINVAL;
+		return call_pkg->nd_command;
+	}
+
+	/* Linux ND commands == NVDIMM_FAMILY_INTEL function numbers */
+	if (nfit_mem->family == NVDIMM_FAMILY_INTEL)
+		return cmd;
+
+	/*
+	 * Force function number validation to fail since 0 is never
+	 * published as a valid function in dsm_mask.
+	 */
+	return 0;
+}
+
 int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 		unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc)
 {
@@ -422,30 +448,23 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 	unsigned long cmd_mask, dsm_mask;
 	u32 offset, fw_status = 0;
 	acpi_handle handle;
-	unsigned int func;
 	const guid_t *guid;
-	int rc, i;
+	int func, rc, i;
 
 	if (cmd_rc)
 		*cmd_rc = -EINVAL;
-	func = cmd;
-	if (cmd == ND_CMD_CALL) {
-		call_pkg = buf;
-		func = call_pkg->nd_command;
-
-		for (i = 0; i < ARRAY_SIZE(call_pkg->nd_reserved2); i++)
-			if (call_pkg->nd_reserved2[i])
-				return -EINVAL;
-	}
 
 	if (nvdimm) {
 		struct acpi_device *adev = nfit_mem->adev;
 
 		if (!adev)
 			return -ENOTTY;
-		if (call_pkg && nfit_mem->family != call_pkg->nd_family)
-			return -ENOTTY;
 
+		if (cmd == ND_CMD_CALL)
+			call_pkg = buf;
+		func = cmd_to_func(nfit_mem, cmd, call_pkg);
+		if (func < 0)
+			return func;
 		dimm_name = nvdimm_name(nvdimm);
 		cmd_name = nvdimm_cmd_name(cmd);
 		cmd_mask = nvdimm_cmd_mask(nvdimm);
@@ -456,6 +475,7 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 	} else {
 		struct acpi_device *adev = to_acpi_dev(acpi_desc);
 
+		func = cmd;
 		cmd_name = nvdimm_bus_cmd_name(cmd);
 		cmd_mask = nd_desc->cmd_mask;
 		dsm_mask = cmd_mask;
@@ -470,7 +490,13 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 	if (!desc || (cmd && (desc->out_num + desc->in_num == 0)))
 		return -ENOTTY;
 
-	if (!test_bit(cmd, &cmd_mask) || !test_bit(func, &dsm_mask))
+	/*
+	 * Check for a valid command.  For ND_CMD_CALL, we also have to
+	 * make sure that the DSM function is supported.
+	 */
+	if (cmd == ND_CMD_CALL && !test_bit(func, &dsm_mask))
+		return -ENOTTY;
+	else if (!test_bit(cmd, &cmd_mask))
 		return -ENOTTY;
 
 	in_obj.type = ACPI_TYPE_PACKAGE;
@@ -1867,6 +1893,13 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
 		return 0;
 	}
 
+	/*
+	 * Function 0 is the command interrogation function, don't
+	 * export it to potential userspace use, and enable it to be
+	 * used as an error value in acpi_nfit_ctl().
+	 */
+	dsm_mask &= ~1UL;
+
 	guid = to_nfit_uuid(nfit_mem->family);
 	for_each_set_bit(i, &dsm_mask, BITS_PER_LONG)
 		if (acpi_check_dsm(adev_dimm->handle, guid,
@@ -2042,11 +2075,6 @@ static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
 		if (!nvdimm)
 			continue;
 
-		rc = nvdimm_security_setup_events(nvdimm);
-		if (rc < 0)
-			dev_warn(acpi_desc->dev,
-				"security event setup failed: %d\n", rc);
-
 		nfit_kernfs = sysfs_get_dirent(nvdimm_kobj(nvdimm)->sd, "nfit");
 		if (nfit_kernfs)
 			nfit_mem->flags_attr = sysfs_get_dirent(nfit_kernfs,

drivers/nvdimm/dimm.c

@@ -26,6 +26,12 @@ static int nvdimm_probe(struct device *dev)
 	struct nvdimm_drvdata *ndd;
 	int rc;
 
+	rc = nvdimm_security_setup_events(dev);
+	if (rc < 0) {
+		dev_err(dev, "security event setup failed: %d\n", rc);
+		return rc;
+	}
+
 	rc = nvdimm_check_config_data(dev);
 	if (rc) {
 		/* not required for non-aliased nvdimm, ex. NVDIMM-N */

drivers/nvdimm/dimm_devs.c

@@ -578,13 +578,25 @@ struct nvdimm *__nvdimm_create(struct nvdimm_bus *nvdimm_bus,
 }
 EXPORT_SYMBOL_GPL(__nvdimm_create);
 
-int nvdimm_security_setup_events(struct nvdimm *nvdimm)
+static void shutdown_security_notify(void *data)
 {
-	nvdimm->sec.overwrite_state = sysfs_get_dirent(nvdimm->dev.kobj.sd,
-			"security");
+	struct nvdimm *nvdimm = data;
+
+	sysfs_put(nvdimm->sec.overwrite_state);
+}
+
+int nvdimm_security_setup_events(struct device *dev)
+{
+	struct nvdimm *nvdimm = to_nvdimm(dev);
+
+	if (nvdimm->sec.state < 0 || !nvdimm->sec.ops
+			|| !nvdimm->sec.ops->overwrite)
+		return 0;
+	nvdimm->sec.overwrite_state = sysfs_get_dirent(dev->kobj.sd, "security");
 	if (!nvdimm->sec.overwrite_state)
-		return -ENODEV;
-	return 0;
+		return -ENOMEM;
+
+	return devm_add_action_or_reset(dev, shutdown_security_notify, nvdimm);
 }
 EXPORT_SYMBOL_GPL(nvdimm_security_setup_events);
 

drivers/nvdimm/nd.h

@@ -250,6 +250,7 @@ long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
 void nvdimm_set_aliasing(struct device *dev);
 void nvdimm_set_locked(struct device *dev);
 void nvdimm_clear_locked(struct device *dev);
+int nvdimm_security_setup_events(struct device *dev);
 #if IS_ENABLED(CONFIG_NVDIMM_KEYS)
 int nvdimm_security_unlock(struct device *dev);
 #else

include/linux/libnvdimm.h

@@ -235,7 +235,6 @@ static inline struct nvdimm *nvdimm_create(struct nvdimm_bus *nvdimm_bus,
 			cmd_mask, num_flush, flush_wpq, NULL, NULL);
 }
 
-int nvdimm_security_setup_events(struct nvdimm *nvdimm);
 const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd);
 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd);
 u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,

tools/testing/nvdimm/dimm_devs.c

@@ -18,8 +18,8 @@ ssize_t security_show(struct device *dev,
 	 * For the test version we need to poll the "hardware" in order
 	 * to get the updated status for unlock testing.
 	 */
-	nvdimm->sec.state = nvdimm_security_state(nvdimm, false);
-	nvdimm->sec.ext_state = nvdimm_security_state(nvdimm, true);
+	nvdimm->sec.state = nvdimm_security_state(nvdimm, NVDIMM_USER);
+	nvdimm->sec.ext_state = nvdimm_security_state(nvdimm, NVDIMM_MASTER);
 
 	switch (nvdimm->sec.state) {
 	case NVDIMM_SECURITY_DISABLED: