[PATCH 4.19 47/57] efi: fix return value of __setup handlers

Greg Kroah-Hartman
2022-03-21T14:01:25Z

From: Randy Dunlap <rdunlap@infradead.org>

[ Upstream commit 9feaf8b387ee0ece9c1d7add308776b502a35d0c ]

When "dump_apple_properties" is used on the kernel boot command line,
it causes an Unknown parameter message and the string is added to init's
argument strings:

Unknown kernel command line parameters "dump_apple_properties
BOOT_IMAGE=/boot/bzImage-517rc6 efivar_ssdt=newcpu_ssdt", will be
passed to user space.

Run /sbin/init as init process
with arguments:
/sbin/init
dump_apple_properties
with environment:
HOME=/
TERM=linux
BOOT_IMAGE=/boot/bzImage-517rc6
efivar_ssdt=newcpu_ssdt

Similarly when "efivar_ssdt=somestring" is used, it is added to the
Unknown parameter message and to init's environment strings, polluting
them (see examples above).

Change the return value of the __setup functions to 1 to indicate
that the __setup options have been handled.

Fixes: 58c5475aba67 ("x86/efi: Retrieve and assign Apple device properties")
Fixes: 475fb4e8b2f4 ("efi / ACPI: load SSTDs from EFI variables")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-efi@vger.kernel.org
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Octavian Purdila <octavian.purdila@intel.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Link: https://lore.kernel.org/r/20220301041851.12459-1-rdunlap@infradead.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/firmware/efi/apple-properties.c | 2 +-
drivers/firmware/efi/efi.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/efi/apple-properties.c b/drivers/firmware/efi/apple-properties.c
index 60a95719ecb8..726a23d45da4 100644
--- a/drivers/firmware/efi/apple-properties.c
+++ b/drivers/firmware/efi/apple-properties.c
@@ -34,7 +34,7 @@ static bool dump_properties __initdata;
static int __init dump_properties_enable(char *arg)
{
dump_properties = true;
- return 0;
+ return 1;
}

__setup("dump_apple_properties", dump_properties_enable);
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index a8180f9090fa..7098744f9276 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -245,7 +245,7 @@ static int __init efivar_ssdt_setup(char *str)
memcpy(efivar_ssdt, str, strlen(str));
else
pr_warn("efivar_ssdt: name too long: %s\n", str);
- return 0;
+ return 1;
}
__setup("efivar_ssdt=", efivar_ssdt_setup);

--
2.34.1