[PATCH] nfc: netlink: avoid NULL pointer dereference on error

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

STALE3977d

2 messages, 2 authors, 2015-10-20 · open the first message on its own page

[PATCH] nfc: netlink: avoid NULL pointer dereference on error

From: Vincent Stehlé <hidden>
Date: 2015-10-07 09:33:41

The function nfc_genl_llc_sdreq() can dereference the dev pointer while
it is NULL on its error path. Create a new error handling label to avoid
that.

This fixes the following coccinelle error:

  ./net/nfc/netlink.c:1175:21-24: ERROR: dev is NULL but dereferenced.

Signed-off-by: Vincent Stehlé <redacted>
Cc: Thierry Escande <redacted>
Cc: Samuel Ortiz <redacted>
---
 net/nfc/netlink.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c
index 853172c..51c48f0 100644
--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c

@@ -1111,7 +1111,7 @@ static int nfc_genl_llc_sdreq(struct sk_buff *skb, struct genl_info *info)
 	dev = nfc_get_device(idx);
 	if (!dev) {
 		rc = -ENODEV;
-		goto exit;
+		goto exit_nodev;
 	}
 
 	device_lock(&dev->dev);

@@ -1176,6 +1176,7 @@ exit:
 
 	nfc_put_device(dev);
 
+exit_nodev:
 	return rc;
 }

-- 
2.5.1

Re: [PATCH] nfc: netlink: avoid NULL pointer dereference on error

From: Samuel Ortiz <hidden>
Date: 2015-10-20 04:50:48

Hi Vincent,

On Wed, Oct 07, 2015 at 11:33:19AM +0200, Vincent Stehlé wrote:

quoted hunk

The function nfc_genl_llc_sdreq() can dereference the dev pointer while
it is NULL on its error path. Create a new error handling label to avoid
that.

This fixes the following coccinelle error:

  ./net/nfc/netlink.c:1175:21-24: ERROR: dev is NULL but dereferenced.

Signed-off-by: Vincent Stehlé <redacted>
Cc: Thierry Escande <redacted>
Cc: Samuel Ortiz <redacted>
---
 net/nfc/netlink.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c
index 853172c..51c48f0 100644
--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c

@@ -1111,7 +1111,7 @@ static int nfc_genl_llc_sdreq(struct sk_buff *skb, struct genl_info *info)
 	dev = nfc_get_device(idx);
 	if (!dev) {
 		rc = -ENODEV;
-		goto exit;
+		goto exit_nodev;
 	}

Julia Lawall sent a better fix that I applied:

-       if (!dev) {
-               rc = -ENODEV;
-               goto exit;
-       }
+       if (!dev)
+               return -ENODEV;

Cheers,
Samuel.

`h`	back out one level
`j`	next message in thread
`k`	previous message in thread
`l`	drill in
`Esc`	close help / fold thread tree
`?`	toggle this help