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* [PATCH 1/3] soundwire: fix sign extension when shifting buf[2] 24 places
@ 2018-01-08 16:52 Vinod Koul
  2018-01-08 16:52 ` [PATCH 2/3] soundwire: intel: fix missing assignment to ret Vinod Koul
  2018-01-08 16:52 ` [PATCH 3/3] soundwire: Fix typo in return value check of sdw_read() Vinod Koul
  0 siblings, 2 replies; 3+ messages in thread
From: Vinod Koul @ 2018-01-08 16:52 UTC (permalink / raw)
  To: Greg KH; +Cc: LKML, Sanyog Kale, Colin Ian King

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>
Acked-by: Vinod Koul <vinod.koul@intel.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);
 
-- 
2.7.4

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2018-01-08 16:49 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2018-01-08 16:52 [PATCH 1/3] soundwire: fix sign extension when shifting buf[2] 24 places Vinod Koul
2018-01-08 16:52 ` [PATCH 2/3] soundwire: intel: fix missing assignment to ret Vinod Koul
2018-01-08 16:52 ` [PATCH 3/3] soundwire: Fix typo in return value check of sdw_read() Vinod Koul

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