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From: Colin King <>
To: Jarkko Nikula <>,
	Andy Shevchenko <>,
	Mika Westerberg <>,
	Wolfram Sang <>,
Subject: [PATCH] i2c: designware-baytrail: fix potential null pointer dereference on dev
Date: Mon, 20 Mar 2017 11:51:23 +0000	[thread overview]
Message-ID: <> (raw)

From: Colin Ian King <>

The assignment to addr requires a call to get_sem_addr that dereferences
dev, however, this dereference occurs before a null pointer check on dev.
Move this assignment after the null check on dev to avoid a potential null
pointer dereference.

Detected by CoverityScan, CID#1419700 ("Dereference before null check")

Fixes: fd476fa22a1f432 ("i2c: designware-baytrail: Add support for cherrytrail")
Signed-off-by: Colin Ian King <>
 drivers/i2c/busses/i2c-designware-baytrail.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c
index 1749a0f5a9fa..2cbb2e9195ca 100644
--- a/drivers/i2c/busses/i2c-designware-baytrail.c
+++ b/drivers/i2c/busses/i2c-designware-baytrail.c
@@ -70,7 +70,7 @@ static void reset_semaphore(struct dw_i2c_dev *dev)
 static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
-	u32 addr = get_sem_addr(dev);
+	u32 addr;
 	int ret;
 	unsigned long start, end;
@@ -94,6 +94,8 @@ static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
 	pm_qos_update_request(&dev->pm_qos, 0);
+	addr = get_sem_addr(dev);
 	/* host driver writes to side band semaphore register */
 	ret = iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, addr, sem);
 	if (ret) {

             reply	other threads:[~2017-03-20 11:52 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-20 11:51 Colin King [this message]
2017-04-19 19:01 ` Wolfram Sang

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