[RESEND] gpu: ipu-v3: prg: avoid possible array underflow

Submitted by Arnd Bergmann on Jan. 16, 2018, 2:31 p.m.

Details

Message ID 20180116143212.1411334-1-arnd@arndb.de
State New
Headers show
Series "gpu: ipu-v3: prg: avoid possible array underflow" ( rev: 2 ) in DRI devel

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Commit Message

Arnd Bergmann Jan. 16, 2018, 2:31 p.m.
gcc-8 reports that we access an array with a negative index
in an error case:

drivers/gpu/ipu-v3/ipu-prg.c: In function 'ipu_prg_channel_disable':
drivers/gpu/ipu-v3/ipu-prg.c:252:43: error: array subscript -22 is below array bounds of 'struct ipu_prg_channel[3]' [-Werror=array-bounds]

This moves the range check in front of the dereference.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
----
Originally sent on Dec 4, 2017. No reply, so resending unchanged.
---
 drivers/gpu/ipu-v3/ipu-prg.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch hide | download patch | download mbox

diff --git a/drivers/gpu/ipu-v3/ipu-prg.c b/drivers/gpu/ipu-v3/ipu-prg.c
index 067365c733c6..0bcb935e525c 100644
--- a/drivers/gpu/ipu-v3/ipu-prg.c
+++ b/drivers/gpu/ipu-v3/ipu-prg.c
@@ -250,7 +250,7 @@  void ipu_prg_channel_disable(struct ipuv3_channel *ipu_chan)
 	struct ipu_prg_channel *chan = &prg->chan[prg_chan];
 	u32 val;
 
-	if (!chan->enabled || prg_chan < 0)
+	if (prg_chan < 0 || !chan->enabled)
 		return;
 
 	pm_runtime_get_sync(prg->dev);

Comments

Hi Arnd,

On Tue, 2018-01-16 at 15:31 +0100, Arnd Bergmann wrote:
> gcc-8 reports that we access an array with a negative index
> in an error case:
> 
> drivers/gpu/ipu-v3/ipu-prg.c: In function 'ipu_prg_channel_disable':
> drivers/gpu/ipu-v3/ipu-prg.c:252:43: error: array subscript -22 is below array bounds of 'struct ipu_prg_channel[3]' [-Werror=array-bounds]
> 
> This moves the range check in front of the dereference.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ----
> Originally sent on Dec 4, 2017. No reply, so resending unchanged.

Thank you, applied to imx-drm/fixes.

regards
Philipp