* [PATCH] ACPI / util: cast data to u64 before shifting to fix sign extension
@ 2016-03-18 15:08 Colin King
0 siblings, 0 replies; only message in thread
From: Colin King @ 2016-03-18 15:08 UTC (permalink / raw)
To: Rafael J . Wysocki, Len Brown, linux-acpi, devel; +Cc: linux-kernel
From: Colin Ian King <colin.king@canonical.com>
obj->buffer.pointer[i] should be cast to u64 to prevent an unintentional
sign extension. For example, if pointer[7] is 0x80, then the value
0xffffffffff000000 is or'd into mask rather than the intended value
0xff00000000000000
Detected with static analysis by CoverityScan
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
drivers/acpi/utils.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index f12a724..050673f 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -692,7 +692,7 @@ bool acpi_check_dsm(acpi_handle handle, const u8 *uuid, int rev, u64 funcs)
mask = obj->integer.value;
else if (obj->type == ACPI_TYPE_BUFFER)
for (i = 0; i < obj->buffer.length && i < 8; i++)
- mask |= (((u8)obj->buffer.pointer[i]) << (i * 8));
+ mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
ACPI_FREE(obj);
/*
--
2.7.3
^ permalink raw reply related [flat|nested] only message in thread
only message in thread, other threads:[~2016-03-18 15:08 UTC | newest]
Thread overview: (only message) (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-03-18 15:08 [PATCH] ACPI / util: cast data to u64 before shifting to fix sign extension Colin King
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).