[PATCH 1/2] Bluetooth: L2CAP: Fix accepting connection request for invalid SPSM

[PATCH 1/2] Bluetooth: L2CAP: Fix accepting connection request for invalid SPSM

[Luiz Augusto von Dentz]

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

The Bluetooth spec states that the valid range for SPSM is from
0x0001-0x00ff so it is invalid to accept values outside of this range:

  BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
  page 1059:
  Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges

CVE: CVE-2022-42896
CC: stable@vger.kernel.org
Reported-by: Tamás Koczka <poprdi@google.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 net/bluetooth/l2cap_core.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index ef725ed41303..2978a34ea33f 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -5813,6 +5813,19 @@ static int l2cap_le_connect_req(struct l2cap_conn *conn,
 	BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm),
 	       scid, mtu, mps);
 
+	/* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
+	 * page 1059:
+	 *
+	 * Valid range: 0x0001-0x00ff
+	 *
+	 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
+	 */
+	if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
+		result = L2CAP_CR_LE_BAD_PSM;
+		chan = NULL;
+		goto response;
+	}
+
 	/* Check if we have socket listening on psm */
 	pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
 					 &conn->hcon->dst, LE_LINK);
@@ -6001,6 +6014,18 @@ static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn,
 
 	psm  = req->psm;
 
+	/* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
+	 * page 1059:
+	 *
+	 * Valid range: 0x0001-0x00ff
+	 *
+	 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
+	 */
+	if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
+		result = L2CAP_CR_LE_BAD_PSM;
+		goto response;
+	}
+
 	BT_DBG("psm 0x%2.2x mtu %u mps %u", __le16_to_cpu(psm), mtu, mps);
 
 	memset(&pdu, 0, sizeof(pdu));
-- 
2.37.3

[PATCH 2/2] Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm

[Luiz Augusto von Dentz]

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

l2cap_global_chan_by_psm shall not return fixed channels as they are not
meant to be connected by (S)PSM.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 net/bluetooth/l2cap_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 2978a34ea33f..cdddd2c779f2 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -1990,7 +1990,7 @@ static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm,
 		if (link_type == LE_LINK && c->src_type == BDADDR_BREDR)
 			continue;
 
-		if (c->psm == psm) {
+		if (c->chan_type != L2CAP_CHAN_FIXED && c->psm == psm) {
 			int src_match, dst_match;
 			int src_any, dst_any;
 
-- 
2.37.3

RE: [1/2] Bluetooth: L2CAP: Fix accepting connection request for invalid SPSM

[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=690674

---Test result---

Test Summary:
CheckPatch                    PASS      2.61 seconds
GitLint                       PASS      1.53 seconds
SubjectPrefix                 PASS      1.27 seconds
BuildKernel                   PASS      33.98 seconds
BuildKernel32                 PASS      30.91 seconds
Incremental Build with patchesPASS      52.58 seconds
TestRunner: Setup             PASS      511.82 seconds
TestRunner: l2cap-tester      PASS      17.23 seconds
TestRunner: iso-tester        PASS      16.10 seconds
TestRunner: bnep-tester       PASS      6.36 seconds
TestRunner: mgmt-tester       PASS      103.63 seconds
TestRunner: rfcomm-tester     PASS      10.15 seconds
TestRunner: sco-tester        PASS      9.48 seconds
TestRunner: ioctl-tester      PASS      10.63 seconds
TestRunner: mesh-tester       PASS      7.82 seconds
TestRunner: smp-tester        PASS      9.52 seconds
TestRunner: userchan-tester   PASS      6.52 seconds



---
Regards,
Linux Bluetooth

Re: [PATCH 1/2] Bluetooth: L2CAP: Fix accepting connection request for invalid SPSM

[Tedd Ho-Jeong An]

Hi Luiz,

On Mon, 2022-10-31 at 16:10 -0700, Luiz Augusto von Dentz wrote:
> From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
> 
> The Bluetooth spec states that the valid range for SPSM is from
> 0x0001-0x00ff so it is invalid to accept values outside of this range:
> 
>   BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
>   page 1059:
>   Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
> 
> CVE: CVE-2022-42896
> CC: stable@vger.kernel.org
> Reported-by: Tamás Koczka <poprdi@google.com>

Reviewed-by: Tedd Ho-Jeong An <tedd.an@intel.com>

> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
> ---
>  net/bluetooth/l2cap_core.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> index ef725ed41303..2978a34ea33f 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -5813,6 +5813,19 @@ static int l2cap_le_connect_req(struct l2cap_conn *conn,
>         BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm),
>                scid, mtu, mps);
>  
> +       /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
> +        * page 1059:
> +        *
> +        * Valid range: 0x0001-0x00ff
> +        *
> +        * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
> +        */
> +       if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
> +               result = L2CAP_CR_LE_BAD_PSM;
> +               chan = NULL;
> +               goto response;
> +       }
> +
>         /* Check if we have socket listening on psm */
>         pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
>                                          &conn->hcon->dst, LE_LINK);
> @@ -6001,6 +6014,18 @@ static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn,
>  
>         psm  = req->psm;
>  
> +       /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
> +        * page 1059:
> +        *
> +        * Valid range: 0x0001-0x00ff
> +        *
> +        * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
> +        */
> +       if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
> +               result = L2CAP_CR_LE_BAD_PSM;
> +               goto response;
> +       }
> +
>         BT_DBG("psm 0x%2.2x mtu %u mps %u", __le16_to_cpu(psm), mtu, mps);
>  
>         memset(&pdu, 0, sizeof(pdu));

Regards,
Tedd

Re: [PATCH 1/2] Bluetooth: L2CAP: Fix accepting connection request for invalid SPSM

[patchwork-bot+bluetooth]

Hello:

This series was applied to bluetooth/bluetooth-next.git (master)
by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>:

On Mon, 31 Oct 2022 16:10:32 -0700 you wrote:
> From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
> 
> The Bluetooth spec states that the valid range for SPSM is from
> 0x0001-0x00ff so it is invalid to accept values outside of this range:
> 
>   BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
>   page 1059:
>   Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
> 
> [...]

Here is the summary with links:
  - [1/2] Bluetooth: L2CAP: Fix accepting connection request for invalid SPSM
    https://git.kernel.org/bluetooth/bluetooth-next/c/a0978378c152
  - [2/2] Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm
    https://git.kernel.org/bluetooth/bluetooth-next/c/6bdbca3c41e4

You are awesome, thank you!
-- 
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