[PATCH] net: dsa: b53: Fix dereference of null dev

Subsystems: broadcom b53/sf2 ethernet switch driver, networking drivers, networking [dsa], the rest

STALE1885d

4 messages, 3 authors, 2021-06-15 · open the first message on its own page

[PATCH] net: dsa: b53: Fix dereference of null dev

From: Colin King <hidden>
Date: 2021-06-12 14:44:16 

From: Colin Ian King <redacted>

Currently pointer priv is dereferencing dev before dev is being null
checked so a potential null pointer dereference can occur. Fix this
by only assigning and using priv if dev is not-null.

Addresses-Coverity: ("Dereference before null check")
Fixes: 16994374a6fc ("net: dsa: b53: Make SRAB driver manage port interrupts")
Signed-off-by: Colin Ian King <redacted>
---
 drivers/net/dsa/b53/b53_srab.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/dsa/b53/b53_srab.c b/drivers/net/dsa/b53/b53_srab.c
index aaa12d73784e..e77ac598f859 100644
--- a/drivers/net/dsa/b53/b53_srab.c
+++ b/drivers/net/dsa/b53/b53_srab.c
@@ -629,11 +629,13 @@ static int b53_srab_probe(struct platform_device *pdev)
 static int b53_srab_remove(struct platform_device *pdev)
 {
 	struct b53_device *dev = platform_get_drvdata(pdev);
-	struct b53_srab_priv *priv = dev->priv;
 
-	b53_srab_intr_set(priv, false);
-	if (dev)
+	if (dev) {
+		struct b53_srab_priv *priv = dev->priv;
+
+		b53_srab_intr_set(priv, false);
 		b53_switch_remove(dev);
+	}
 
 	return 0;
 }
-- 
2.31.1

Re: [PATCH] net: dsa: b53: Fix dereference of null dev

From: Vladimir Oltean <olteanv@gmail.com>
Date: 2021-06-12 15:04:02 

On Sat, Jun 12, 2021 at 03:44:07PM +0100, Colin King wrote:
quoted hunk
From: Colin Ian King <redacted>

Currently pointer priv is dereferencing dev before dev is being null
checked so a potential null pointer dereference can occur. Fix this
by only assigning and using priv if dev is not-null.

Addresses-Coverity: ("Dereference before null check")
Fixes: 16994374a6fc ("net: dsa: b53: Make SRAB driver manage port interrupts")
Signed-off-by: Colin Ian King <redacted>
---
 drivers/net/dsa/b53/b53_srab.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/dsa/b53/b53_srab.c b/drivers/net/dsa/b53/b53_srab.c
index aaa12d73784e..e77ac598f859 100644
--- a/drivers/net/dsa/b53/b53_srab.c
+++ b/drivers/net/dsa/b53/b53_srab.c
@@ -629,11 +629,13 @@ static int b53_srab_probe(struct platform_device *pdev)
 static int b53_srab_remove(struct platform_device *pdev)
 {
 	struct b53_device *dev = platform_get_drvdata(pdev);
-	struct b53_srab_priv *priv = dev->priv;
 
-	b53_srab_intr_set(priv, false);
-	if (dev)
+	if (dev) {
+		struct b53_srab_priv *priv = dev->priv;
+
+		b53_srab_intr_set(priv, false);
 		b53_switch_remove(dev);
+	}
 
 	return 0;
 }
-- 
2.31.1
I think the better question is how can "dev" be NULL in the first
place, since b53_srab_probe() does an unconditional platform_set_drvdata()
with what appears to be a non-NULL dev.

Re: [PATCH] net: dsa: b53: Fix dereference of null dev

From: Dan Carpenter <hidden>
Date: 2021-06-14 11:39:43 

On Sat, Jun 12, 2021 at 03:44:07PM +0100, Colin King wrote:
quoted hunk
From: Colin Ian King <redacted>

Currently pointer priv is dereferencing dev before dev is being null
checked so a potential null pointer dereference can occur. Fix this
by only assigning and using priv if dev is not-null.

Addresses-Coverity: ("Dereference before null check")
Fixes: 16994374a6fc ("net: dsa: b53: Make SRAB driver manage port interrupts")
Signed-off-by: Colin Ian King <redacted>
---
 drivers/net/dsa/b53/b53_srab.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/dsa/b53/b53_srab.c b/drivers/net/dsa/b53/b53_srab.c
index aaa12d73784e..e77ac598f859 100644
--- a/drivers/net/dsa/b53/b53_srab.c
+++ b/drivers/net/dsa/b53/b53_srab.c
@@ -629,11 +629,13 @@ static int b53_srab_probe(struct platform_device *pdev)
 static int b53_srab_remove(struct platform_device *pdev)
 {
 	struct b53_device *dev = platform_get_drvdata(pdev);
-	struct b53_srab_priv *priv = dev->priv;
 
-	b53_srab_intr_set(priv, false);
-	if (dev)
+	if (dev) {
This is the remove function and "dev" can't be NULL at this point.
Better to just remove the NULL check.

regards,
dan carpenter

Re: [PATCH] net: dsa: b53: Fix dereference of null dev

From: Colin Ian King <hidden>
Date: 2021-06-15 08:33:56 

On 14/06/2021 12:28, Dan Carpenter wrote:
On Sat, Jun 12, 2021 at 03:44:07PM +0100, Colin King wrote:
quoted
From: Colin Ian King <redacted>

Currently pointer priv is dereferencing dev before dev is being null
checked so a potential null pointer dereference can occur. Fix this
by only assigning and using priv if dev is not-null.

Addresses-Coverity: ("Dereference before null check")
Fixes: 16994374a6fc ("net: dsa: b53: Make SRAB driver manage port interrupts")
Signed-off-by: Colin Ian King <redacted>
---
 drivers/net/dsa/b53/b53_srab.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/dsa/b53/b53_srab.c b/drivers/net/dsa/b53/b53_srab.c
index aaa12d73784e..e77ac598f859 100644
--- a/drivers/net/dsa/b53/b53_srab.c
+++ b/drivers/net/dsa/b53/b53_srab.c
@@ -629,11 +629,13 @@ static int b53_srab_probe(struct platform_device *pdev)
 static int b53_srab_remove(struct platform_device *pdev)
 {
 	struct b53_device *dev = platform_get_drvdata(pdev);
-	struct b53_srab_priv *priv = dev->priv;
 
-	b53_srab_intr_set(priv, false);
-	if (dev)
+	if (dev) {
This is the remove function and "dev" can't be NULL at this point.
Better to just remove the NULL check.
Will do.

regards,
dan carpenter




    
  

  
    

      

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