[PATCH next] Bluetooth: L2CAP: Fix NULL dereference in l2cap_recv_acldata()

[PATCH next] Bluetooth: L2CAP: Fix NULL dereference in l2cap_recv_acldata()

[Dan Carpenter]

The "conn" pointer is NULL so this "goto drop;" will lead to a NULL
dereference when we call mutex_unlock(&conn->lock). Free the skb and
return directly instead.

Fixes: dd6367916d2d ("Bluetooth: L2CAP: Fix corrupted list in hci_chan_del")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 net/bluetooth/l2cap_core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 6cdc1dc3a7f9..fec11e576f31 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -7456,8 +7456,10 @@ void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
 
 	hci_dev_unlock(hcon->hdev);
 
-	if (!conn)
-		goto drop;
+	if (!conn) {
+		kfree_skb(skb);
+		return;
+	}
 
 	BT_DBG("conn %p len %u flags 0x%x", conn, skb->len, flags);
 
-- 
2.47.2

RE: [next] Bluetooth: L2CAP: Fix NULL dereference in l2cap_recv_acldata()

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 2028 bytes --]

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=933263

---Test result---

Test Summary:
CheckPatch                    PENDING   0.21 seconds
GitLint                       PENDING   0.21 seconds
SubjectPrefix                 PASS      0.12 seconds
BuildKernel                   PASS      25.53 seconds
CheckAllWarning               PASS      28.14 seconds
CheckSparse                   PASS      33.87 seconds
BuildKernel32                 PASS      25.79 seconds
TestRunnerSetup               PASS      437.43 seconds
TestRunner_l2cap-tester       PASS      20.46 seconds
TestRunner_iso-tester         PASS      31.68 seconds
TestRunner_bnep-tester        PASS      4.96 seconds
TestRunner_mgmt-tester        FAIL      123.37 seconds
TestRunner_rfcomm-tester      PASS      7.61 seconds
TestRunner_sco-tester         PASS      9.45 seconds
TestRunner_ioctl-tester       PASS      7.95 seconds
TestRunner_mesh-tester        PASS      6.08 seconds
TestRunner_smp-tester         PASS      7.07 seconds
TestRunner_userchan-tester    PASS      5.13 seconds
IncrementalBuild              PENDING   0.91 seconds

Details
##############################
Test: CheckPatch - PENDING
Desc: Run checkpatch.pl script
Output:

##############################
Test: GitLint - PENDING
Desc: Run gitlint
Output:

##############################
Test: TestRunner_mgmt-tester - FAIL
Desc: Run mgmt-tester with test-runner
Output:
Total: 490, Passed: 484 (98.8%), Failed: 2, Not Run: 4

Failed Test Cases
LL Privacy - Add Device 3 (AL is full)               Failed       0.206 seconds
LL Privacy - Set Flags 3 (2 Devices to RL)           Failed       0.189 seconds
##############################
Test: IncrementalBuild - PENDING
Desc: Incremental build with the patches in the series
Output:



---
Regards,
Linux Bluetooth

Re: [PATCH next] Bluetooth: L2CAP: Fix NULL dereference in l2cap_recv_acldata()

[Luiz Augusto von Dentz]

Hi Dan,

On Wed, Feb 12, 2025 at 11:40 AM Dan Carpenter <dan.carpenter@linaro.org> wrote:
>
> The "conn" pointer is NULL so this "goto drop;" will lead to a NULL
> dereference when we call mutex_unlock(&conn->lock). Free the skb and
> return directly instead.
>
> Fixes: dd6367916d2d ("Bluetooth: L2CAP: Fix corrupted list in hci_chan_del")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
>  net/bluetooth/l2cap_core.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> index 6cdc1dc3a7f9..fec11e576f31 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -7456,8 +7456,10 @@ void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
>
>         hci_dev_unlock(hcon->hdev);
>
> -       if (!conn)
> -               goto drop;
> +       if (!conn) {
> +               kfree_skb(skb);
> +               return;
> +       }
>
>         BT_DBG("conn %p len %u flags 0x%x", conn, skb->len, flags);
>
> --
> 2.47.2

I went ahead and fixed this in place since it has not been sent to net
yet, I did add your Signed-off-by though.

-- 
Luiz Augusto von Dentz

Re: [PATCH next] Bluetooth: L2CAP: Fix NULL dereference in l2cap_recv_acldata()

[Dan Carpenter]

On Wed, Feb 12, 2025 at 05:23:42PM -0500, Luiz Augusto von Dentz wrote:
> Hi Dan,
> 
> On Wed, Feb 12, 2025 at 11:40 AM Dan Carpenter <dan.carpenter@linaro.org> wrote:
> >
> > The "conn" pointer is NULL so this "goto drop;" will lead to a NULL
> > dereference when we call mutex_unlock(&conn->lock). Free the skb and
> > return directly instead.
> >
> > Fixes: dd6367916d2d ("Bluetooth: L2CAP: Fix corrupted list in hci_chan_del")
> > Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> > ---
> >  net/bluetooth/l2cap_core.c | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> > index 6cdc1dc3a7f9..fec11e576f31 100644
> > --- a/net/bluetooth/l2cap_core.c
> > +++ b/net/bluetooth/l2cap_core.c
> > @@ -7456,8 +7456,10 @@ void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
> >
> >         hci_dev_unlock(hcon->hdev);
> >
> > -       if (!conn)
> > -               goto drop;
> > +       if (!conn) {
> > +               kfree_skb(skb);
> > +               return;
> > +       }
> >
> >         BT_DBG("conn %p len %u flags 0x%x", conn, skb->len, flags);
> >
> > --
> > 2.47.2
> 
> I went ahead and fixed this in place since it has not been sent to net
> yet, I did add your Signed-off-by though.

Thanks.

regards,
dan carpenter