[PATCH] ACPI: APEI: EINJ: Limit error type to 32-bit width

[Shuai Xue]

The bit map of error types to inject is 32-bit width[1]. Add parameter
check to reflect the fact.

[1] ACPI Specification 6.4, Section 18.6.4. Error Types

Signed-off-by: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>
---
 drivers/acpi/apei/einj.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c
index ab86b2f4e719..b4373e575660 100644
--- a/drivers/acpi/apei/einj.c
+++ b/drivers/acpi/apei/einj.c
@@ -616,6 +616,10 @@ static int error_type_set(void *data, u64 val)
 	u32 available_error_type = 0;
 	u32 tval, vendor;
 
+	/* Only low 32 bits for error type are valid */
+	if (val & GENMASK_ULL(63, 32))
+		return -EINVAL;
+
 	/*
 	 * Vendor defined types have 0x80000000 bit set, and
 	 * are not enumerated by ACPI_EINJ_GET_ERROR_TYPE
-- 
2.20.1.12.g72788fdb