[PATCH] nfc: nci: fix potential NULL pointer dereference

Subsystems: networking [general], nfc subsystem, the rest

STALE3405d

8 messages, 3 authors, 2017-06-23 · open the first message on its own page

[PATCH] nfc: nci: fix potential NULL pointer dereference

From: Gustavo A. R. Silva <hidden>
Date: 2017-06-12 22:02:35 

NULL check at line 76: if (conn_info) {, implies that pointer conn_info
might be NULL, but this pointer is being previously dereferenced,
which might cause a NULL pointer dereference.

Add NULL check before dereferencing pointer conn_info in order to
avoid a potential NULL pointer dereference.

Addresses-Coverity-ID: 1362349
Signed-off-by: Gustavo A. R. Silva <redacted>
---
 net/nfc/nci/core.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 61fff42..d2198ce 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -70,14 +70,13 @@ int nci_get_conn_info_by_dest_type_params(struct nci_dev *ndev, u8 dest_type,
 	struct nci_conn_info *conn_info;
 
 	list_for_each_entry(conn_info, &ndev->conn_info_list, list) {
-		if (conn_info->dest_type == dest_type) {
+		if (conn_info && conn_info->dest_type == dest_type) {
 			if (!params)
 				return conn_info->conn_id;
-			if (conn_info) {
-				if (params->id == conn_info->dest_params->id &&
-				    params->protocol == conn_info->dest_params->protocol)
-					return conn_info->conn_id;
-			}
+
+			if (params->id == conn_info->dest_params->id &&
+			    params->protocol == conn_info->dest_params->protocol)
+				return conn_info->conn_id;
 		}
 	}
 
-- 
2.5.0

Re: nfc: nci: fix potential NULL pointer dereference

From: Guenter Roeck <linux@roeck-us.net>
Date: 2017-06-12 22:22:00 

On Mon, Jun 12, 2017 at 05:02:23PM -0500, Gustavo A. R. Silva wrote:
quoted hunk
NULL check at line 76: if (conn_info) {, implies that pointer conn_info
might be NULL, but this pointer is being previously dereferenced,
which might cause a NULL pointer dereference.

Add NULL check before dereferencing pointer conn_info in order to
avoid a potential NULL pointer dereference.

Addresses-Coverity-ID: 1362349
Signed-off-by: Gustavo A. R. Silva <redacted>
---
 net/nfc/nci/core.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 61fff42..d2198ce 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -70,14 +70,13 @@ int nci_get_conn_info_by_dest_type_params(struct nci_dev *ndev, u8 dest_type,
 	struct nci_conn_info *conn_info;
 
 	list_for_each_entry(conn_info, &ndev->conn_info_list, list) {
conn_info is set in list_for_each_entry() using container_of(),
which is never NULL. Plus, it is dereferenced there as well.
The check is unnecessary.

Guenter
quoted hunk
-		if (conn_info->dest_type == dest_type) {
+		if (conn_info && conn_info->dest_type == dest_type) {
 			if (!params)
 				return conn_info->conn_id;
-			if (conn_info) {
-				if (params->id == conn_info->dest_params->id &&
-				    params->protocol == conn_info->dest_params->protocol)
-					return conn_info->conn_id;
-			}
+
+			if (params->id == conn_info->dest_params->id &&
+			    params->protocol == conn_info->dest_params->protocol)
+				return conn_info->conn_id;
 		}
 	}

Re: nfc: nci: fix potential NULL pointer dereference

From: Gustavo A. R. Silva <hidden>
Date: 2017-06-12 22:53:16 

Hi Guenter,

Please, see my comments below

Quoting Guenter Roeck [off-list ref]:

On Mon, Jun 12, 2017 at 05:02:23PM -0500, Gustavo A. R. Silva wrote:
quoted
NULL check at line 76: if (conn_info) {, implies that pointer conn_info
might be NULL, but this pointer is being previously dereferenced,
which might cause a NULL pointer dereference.

Add NULL check before dereferencing pointer conn_info in order to
avoid a potential NULL pointer dereference.

Addresses-Coverity-ID: 1362349
Signed-off-by: Gustavo A. R. Silva <redacted>
---
 net/nfc/nci/core.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 61fff42..d2198ce 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -70,14 +70,13 @@ int nci_get_conn_info_by_dest_type_params(struct nci_dev *ndev, u8 dest_type,
 	struct nci_conn_info *conn_info;

 	list_for_each_entry(conn_info, &ndev->conn_info_list, list) {
conn_info is set in list_for_each_entry() using container_of(),
which is never NULL. Plus, it is dereferenced there as well.
The check is unnecessary.
Thanks for clarifying.

Guenter
quoted
-		if (conn_info->dest_type == dest_type) {
+		if (conn_info && conn_info->dest_type == dest_type) {
 			if (!params)
 				return conn_info->conn_id;
-			if (conn_info) {
So, this NULL check could be removed as it seems it is not useful at all ?
quoted
-				if (params->id == conn_info->dest_params->id &&
-				    params->protocol == conn_info->dest_params->protocol)
-					return conn_info->conn_id;
-			}
+
+			if (params->id == conn_info->dest_params->id &&
+			    params->protocol == conn_info->dest_params->protocol)
+				return conn_info->conn_id;
 		}
 	}
Thank you

Re: nfc: nci: fix potential NULL pointer dereference

From: Guenter Roeck <linux@roeck-us.net>
Date: 2017-06-13 00:32:01 

On 06/12/2017 03:28 PM, Gustavo A. R. Silva wrote:
Hi Guenter,

Please, see my comments below

Quoting Guenter Roeck [off-list ref]:
quoted
On Mon, Jun 12, 2017 at 05:02:23PM -0500, Gustavo A. R. Silva wrote:
quoted
NULL check at line 76: if (conn_info) {, implies that pointer conn_info
might be NULL, but this pointer is being previously dereferenced,
which might cause a NULL pointer dereference.

Add NULL check before dereferencing pointer conn_info in order to
avoid a potential NULL pointer dereference.

Addresses-Coverity-ID: 1362349
Signed-off-by: Gustavo A. R. Silva <redacted>
---
 net/nfc/nci/core.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 61fff42..d2198ce 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -70,14 +70,13 @@ int nci_get_conn_info_by_dest_type_params(struct nci_dev *ndev, u8 dest_type,
     struct nci_conn_info *conn_info;

     list_for_each_entry(conn_info, &ndev->conn_info_list, list) {
conn_info is set in list_for_each_entry() using container_of(),
which is never NULL. Plus, it is dereferenced there as well.
The check is unnecessary.
Thanks for clarifying.
quoted
Guenter
quoted
-        if (conn_info->dest_type == dest_type) {
+        if (conn_info && conn_info->dest_type == dest_type) {
             if (!params)
                 return conn_info->conn_id;
-            if (conn_info) {
So, this NULL check could be removed as it seems it is not useful at all ?
Exactly.
quoted
quoted
-                if (params->id == conn_info->dest_params->id &&
-                    params->protocol == conn_info->dest_params->protocol)
-                    return conn_info->conn_id;
-            }
+
+            if (params->id == conn_info->dest_params->id &&
+                params->protocol == conn_info->dest_params->protocol)
+                return conn_info->conn_id;
         }
     }
Thank you
-- 
Gustavo A. R. Silva

[PATCH] nfc: nci: remove unnecessary null check

From: Gustavo A. R. Silva <hidden>
Date: 2017-06-13 16:37:24 

Remove unnecessary NULL check for pointer conn_info.
conn_info is set in list_for_each_entry() using container_of(),
which is never NULL.

Addresses-Coverity-ID: 1362349
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Gustavo A. R. Silva <redacted>
---
 net/nfc/nci/core.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 61fff42..c15cb88 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -73,11 +73,10 @@ int nci_get_conn_info_by_dest_type_params(struct nci_dev *ndev, u8 dest_type,
 		if (conn_info->dest_type == dest_type) {
 			if (!params)
 				return conn_info->conn_id;
-			if (conn_info) {
-				if (params->id == conn_info->dest_params->id &&
-				    params->protocol == conn_info->dest_params->protocol)
-					return conn_info->conn_id;
-			}
+
+			if (params->id == conn_info->dest_params->id &&
+			    params->protocol == conn_info->dest_params->protocol)
+				return conn_info->conn_id;
 		}
 	}
 
-- 
2.5.0

Re: [PATCH] nfc: nci: remove unnecessary null check

From: Guenter Roeck <linux@roeck-us.net>
Date: 2017-06-15 17:29:09 

On Tue, Jun 13, 2017 at 11:37:18AM -0500, Gustavo A. R. Silva wrote:
Remove unnecessary NULL check for pointer conn_info.
conn_info is set in list_for_each_entry() using container_of(),
which is never NULL.

Addresses-Coverity-ID: 1362349
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Gustavo A. R. Silva <redacted>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
quoted hunk
---
 net/nfc/nci/core.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 61fff42..c15cb88 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -73,11 +73,10 @@ int nci_get_conn_info_by_dest_type_params(struct nci_dev *ndev, u8 dest_type,
 		if (conn_info->dest_type == dest_type) {
 			if (!params)
 				return conn_info->conn_id;
-			if (conn_info) {
-				if (params->id == conn_info->dest_params->id &&
-				    params->protocol == conn_info->dest_params->protocol)
-					return conn_info->conn_id;
-			}
+
+			if (params->id == conn_info->dest_params->id &&
+			    params->protocol == conn_info->dest_params->protocol)
+				return conn_info->conn_id;
 		}
 	}
 
-- 
2.5.0

Re: [PATCH] nfc: nci: remove unnecessary null check

From: Samuel Ortiz <hidden>
Date: 2017-06-22 22:35:34 

Hi Gustavo,

On Tue, Jun 13, 2017 at 11:37:18AM -0500, Gustavo A. R. Silva wrote:
Remove unnecessary NULL check for pointer conn_info.
conn_info is set in list_for_each_entry() using container_of(),
which is never NULL.

Addresses-Coverity-ID: 1362349
Cc: Guenter Roeck <redacted>
Signed-off-by: Gustavo A. R. Silva <garsilva-L1vi/lXTdts+Va1GwOuvDg@public.gmane.org>
---
 net/nfc/nci/core.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)
Applied to nfc-next, thanks.

Cheers,
Samuel.

Re: [PATCH] nfc: nci: remove unnecessary null check

From: Gustavo A. R. Silva <hidden>
Date: 2017-06-23 01:46:13 

Hi Samuel,

Quoting Samuel Ortiz [off-list ref]:

Hi Gustavo,

On Tue, Jun 13, 2017 at 11:37:18AM -0500, Gustavo A. R. Silva wrote:
quoted
Remove unnecessary NULL check for pointer conn_info.
conn_info is set in list_for_each_entry() using container_of(),
which is never NULL.

Addresses-Coverity-ID: 1362349
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Gustavo A. R. Silva <redacted>
---
 net/nfc/nci/core.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)
Applied to nfc-next, thanks.
Absolutely, glad to help.

Thanks
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