Commit d26cbdd2 authored by Colin Ian King's avatar Colin Ian King Committed by Hans de Goede
Browse files

platform/surface: fix potential integer overflow on shift of a int 



The left shift of int 32 bit integer constant 1 is evaluated using 32 bit
arithmetic and then passed as a 64 bit function argument. In the case where
func is 32 or more this can lead to an oveflow.  Avoid this by shifting
using the BIT_ULL macro instead.

Addresses-Coverity: ("Unintentional integer overflow")
Fixes: fc00bc8a ("platform/surface: Add Surface ACPI Notify driver")
Signed-off-by: default avatarColin Ian King <colin.king@canonical.com>
Reviewed-by: default avatarMaximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20210111144648.20498-1-colin.king@canonical.com


Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
parent d69cd7ee

drivers/platform/surface/surface_acpi_notify.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -188,7 +188,7 @@ static int san_acpi_notify_event(struct device *dev, u64 func, 
	union acpi_object *obj;

	union acpi_object *obj;

	int status = 0;

	int status = 0;





	if (!acpi_check_dsm(san, &SAN_DSM_UUID, SAN_DSM_REVISION, 1 << func))

	if (!acpi_check_dsm(san, &SAN_DSM_UUID, SAN_DSM_REVISION, BIT_ULL(func)))

		return 0;

		return 0;





	dev_dbg(dev, "notify event %#04llx\n", func);

	dev_dbg(dev, "notify event %#04llx\n", func);