[PATCH] Bluetooth: 6LoWPAN: Add missing check for skb_clone

[PATCH] Bluetooth: 6LoWPAN: Add missing check for skb_clone

[Jiasheng Jiang]

Add the check for the return value of skb_clone since it may return NULL
pointer and cause NULL pointer dereference in send_pkt.

Fixes: 18722c247023 ("Bluetooth: Enable 6LoWPAN support for BT LE devices")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
---
 net/bluetooth/6lowpan.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index 4eb1b3ced0d2..bf42a0b03e20 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -477,6 +477,10 @@ static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
 			int ret;
 
 			local_skb = skb_clone(skb, GFP_ATOMIC);
+			if (!local_skb) {
+				rcu_read_unlock();
+				return -ENOMEM;
+			}
 
 			BT_DBG("xmit %s to %pMR type %u IP %pI6c chan %p",
 			       netdev->name,
-- 
2.25.1

RE: Bluetooth: 6LoWPAN: Add missing check for skb_clone

[bluez.test.bot]

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This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=729360

---Test result---

Test Summary:
CheckPatch                    PASS      0.61 seconds
GitLint                       PASS      0.29 seconds
SubjectPrefix                 PASS      0.10 seconds
BuildKernel                   PASS      31.73 seconds
CheckAllWarning               PASS      35.05 seconds
CheckSparse                   PASS      39.86 seconds
CheckSmatch                   PASS      107.69 seconds
BuildKernel32                 PASS      31.26 seconds
TestRunnerSetup               PASS      444.70 seconds
TestRunner_l2cap-tester       PASS      17.17 seconds
TestRunner_iso-tester         PASS      17.53 seconds
TestRunner_bnep-tester        PASS      5.62 seconds
TestRunner_mgmt-tester        PASS      114.29 seconds
TestRunner_rfcomm-tester      PASS      9.09 seconds
TestRunner_sco-tester         PASS      8.41 seconds
TestRunner_ioctl-tester       PASS      9.86 seconds
TestRunner_mesh-tester        PASS      7.27 seconds
TestRunner_smp-tester         PASS      8.31 seconds
TestRunner_userchan-tester    PASS      5.97 seconds
IncrementalBuild              PASS      28.66 seconds



---
Regards,
Linux Bluetooth

Re: [PATCH] Bluetooth: 6LoWPAN: Add missing check for skb_clone

[Simon Horman]

On Mon, Mar 13, 2023 at 05:03:46PM +0800, Jiasheng Jiang wrote:
> Add the check for the return value of skb_clone since it may return NULL
> pointer and cause NULL pointer dereference in send_pkt.
> 
> Fixes: 18722c247023 ("Bluetooth: Enable 6LoWPAN support for BT LE devices")
> Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
> ---
>  net/bluetooth/6lowpan.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
> index 4eb1b3ced0d2..bf42a0b03e20 100644
> --- a/net/bluetooth/6lowpan.c
> +++ b/net/bluetooth/6lowpan.c
> @@ -477,6 +477,10 @@ static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
>  			int ret;
>  
>  			local_skb = skb_clone(skb, GFP_ATOMIC);
> +			if (!local_skb) {
> +				rcu_read_unlock();
> +				return -ENOMEM;
> +			}

Further down in this loop an error is handled as follows,
I wonder if that pattern is appropriate here too.

			ret = send_pkt(pentry->chan, local_skb, netdev);
			if (ret < 0)
				err = ret;

>  			BT_DBG("xmit %s to %pMR type %u IP %pI6c chan %p",
>  			       netdev->name,
> -- 
> 2.25.1
>