[PATCH v2] platform/x86: dell-smbios: Fix error path in dell_smbios_init()

[Aleksandr Mishin]

In case of error in build_tokens_sysfs(), all the memory that has been
allocated is freed at end of this function. But then free_group() is
called which performs memory deallocation again.

Also, instead of free_group() call, there should be exit_dell_smbios_smm()
and exit_dell_smbios_wmi() calls, since there is initialization, but there
is no release of resources in case of an error.

Fix this issue by replacing free_group() call with exit_dell_smbios_wmi()
and exit_dell_smbios_smm().

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 33b9ca1e53b4 ("platform/x86: dell-smbios: Add a sysfs interface for SMBIOS tokens")
Signed-off-by: Aleksandr Mishin <amishin@xxxxxxxxxx>
---
v2: Update comment message for a more detailed description of issues

 drivers/platform/x86/dell/dell-smbios-base.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/x86/dell/dell-smbios-base.c b/drivers/platform/x86/dell/dell-smbios-base.c
index 6565fac24cde..73e41eb69cb5 100644
--- a/drivers/platform/x86/dell/dell-smbios-base.c
+++ b/drivers/platform/x86/dell/dell-smbios-base.c
@@ -622,7 +622,10 @@ static int __init dell_smbios_init(void)
 	return 0;
 
 fail_sysfs:
-	free_group(platform_device);
+	if (!wmi)
+		exit_dell_smbios_wmi();
+	if (!smm)
+		exit_dell_smbios_smm();
 
 fail_create_group:
 	platform_device_del(platform_device);
-- 
2.30.2