[alsa-devel] [PATCH][next] soundwire: fix sign extension when shifting buf[2] 24 places
From: Colin Ian King colin.king@canonical.com
The buf[2] left shift by 24 bits is promoted to int (32 bit signed) and then signed-extended to unsigned long long. Hence if the upper bit to buf[2] is set then all the upper bits of addr end up as 1. Fix this by casting it to u64 before shifting it. Also replace the unsigned long long casts to u64 casts to match the same type of addr.
Detected by CoverityScan, CID#1463147 ("Unintended sign extension")
Fixes: d52d7a1be02c ("soundwire: Add Slave status handling helpers") Signed-off-by: Colin Ian King colin.king@canonical.com --- drivers/soundwire/bus.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 4c345197eb55..7211ecc62015 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -522,8 +522,8 @@ static int sdw_program_device_num(struct sdw_bus *bus) * bits to avoid truncation due to size limit. */ addr = buf[5] | (buf[4] << 8) | (buf[3] << 16) | - (buf[2] << 24) | ((unsigned long long)buf[1] << 32) | - ((unsigned long long)buf[0] << 40); + ((u64)buf[2] << 24) | ((u64)buf[1] << 32) | + ((u64)buf[0] << 40);
sdw_extract_slave_id(bus, addr, &id);
On Thu, Dec 21, 2017 at 11:51:13PM +0000, Colin King wrote:
From: Colin Ian King colin.king@canonical.com
The buf[2] left shift by 24 bits is promoted to int (32 bit signed) and then signed-extended to unsigned long long. Hence if the upper bit to buf[2] is set then all the upper bits of addr end up as 1. Fix this by casting it to u64 before shifting it. Also replace the unsigned long long casts to u64 casts to match the same type of addr.
Applied, thanks
Detected by CoverityScan, CID#1463147 ("Unintended sign extension")
Fixes: d52d7a1be02c ("soundwire: Add Slave status handling helpers") Signed-off-by: Colin Ian King colin.king@canonical.com
drivers/soundwire/bus.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 4c345197eb55..7211ecc62015 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -522,8 +522,8 @@ static int sdw_program_device_num(struct sdw_bus *bus) * bits to avoid truncation due to size limit. */ addr = buf[5] | (buf[4] << 8) | (buf[3] << 16) |
(buf[2] << 24) | ((unsigned long long)buf[1] << 32) |
((unsigned long long)buf[0] << 40);
((u64)buf[2] << 24) | ((u64)buf[1] << 32) |
((u64)buf[0] << 40);
sdw_extract_slave_id(bus, addr, &id);
-- 2.14.1
participants (2)
-
Colin King
-
Vinod Koul