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[v4,04/11,media] ddbridge: check pointers before dereferencing

Message ID 20170812115602.18124-5-d.scheller.oss@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Daniel Scheller Aug. 12, 2017, 11:55 a.m. UTC 
From: Daniel Scheller <d.scheller@gmx.net>

Fixes two warnings reported by smatch:

  drivers/media/pci/ddbridge/ddbridge-core.c:240 ddb_redirect() warn: variable dereferenced before check 'idev' (see line 238)
  drivers/media/pci/ddbridge/ddbridge-core.c:240 ddb_redirect() warn: variable dereferenced before check 'pdev' (see line 238)

Fixed by moving the existing checks up before accessing members.

Cc: Ralph Metzler <rjkm@metzlerbros.de>
Signed-off-by: Daniel Scheller <d.scheller@gmx.net>
Tested-by: Richard Scobie <r.scobie@clear.net.nz>
Tested-by: Jasmin Jessich <jasmin@anw.at>
Tested-by: Dietmar Spingler <d_spingler@freenet.de>
Tested-by: Manfred Knick <Manfred.Knick@t-online.de>
---
 drivers/media/pci/ddbridge/ddbridge-core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
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Patch

diff --git a/drivers/media/pci/ddbridge/ddbridge-core.c b/drivers/media/pci/ddbridge/ddbridge-core.c
index bbd8d556175b..d7bf01f38d98 100644
--- a/drivers/media/pci/ddbridge/ddbridge-core.c
+++ b/drivers/media/pci/ddbridge/ddbridge-core.c
@@ -170,10 +170,10 @@  static int ddb_redirect(u32 i, u32 p)
 	struct ddb *pdev = ddbs[(p >> 4) & 0x3f];
 	struct ddb_port *port;
 
-	if (!idev->has_dma || !pdev->has_dma)
-		return -EINVAL;
 	if (!idev || !pdev)
 		return -EINVAL;
+	if (!idev->has_dma || !pdev->has_dma)
+		return -EINVAL;
 
 	port = &pdev->port[p & 0x0f];
 	if (!port->output)