diff mbox

[V2] dmaengine: coh901318: fix integer overflow when shifting more than 32 places

Message ID 20160929181438.14374-1-colin.king@canonical.com (mailing list archive)
State New, archived
Headers show

Commit Message

Colin King Sept. 29, 2016, 6:14 p.m. UTC 
From: Colin Ian King <colin.king@canonical.com>

Currently U300_DMA_CHANNELS is set to 40, meaning that the shift of 1 can
be more than 32 places, which leads to a 32 bit integer overflow. Fix this
by using 1ULL instead of 1 before shifting it.  Also add braces on the
for-loop to keep with coding style conventions.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/dma/coh901318.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Vinod Koul Sept. 30, 2016, 5:49 p.m. UTC | #1 
On Thu, Sep 29, 2016 at 07:14:38PM +0100, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> Currently U300_DMA_CHANNELS is set to 40, meaning that the shift of 1 can
> be more than 32 places, which leads to a 32 bit integer overflow. Fix this
> by using 1ULL instead of 1 before shifting it.  Also add braces on the
> for-loop to keep with coding style conventions.

Applied, thanks
diff mbox

Patch

diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c
index 2835f3e..74794c9 100644
--- a/drivers/dma/coh901318.c
+++ b/drivers/dma/coh901318.c
@@ -1352,9 +1352,10 @@  static ssize_t coh901318_debugfs_read(struct file *file, char __user *buf,
 
 	tmp += sprintf(tmp, "DMA -- enabled dma channels\n");
 
-	for (i = 0; i < U300_DMA_CHANNELS; i++)
-		if (started_channels & (1 << i))
+	for (i = 0; i < U300_DMA_CHANNELS; i++) {
+		if (started_channels & (1ULL << i))
 			tmp += sprintf(tmp, "channel %d\n", i);
+	}
 
 	tmp += sprintf(tmp, "Pool alloc nbr %d\n", pool_count);