From e2e49e214145a8f6ece6ecd52fec63ebc2b27ce9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Danis?= Date: Mon, 14 Apr 2025 11:08:15 +0200 Subject: [PATCH 1/2] Bluetooth: l2cap: Process valid commands in too long frame MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This is required for passing PTS test cases: - L2CAP/COS/CED/BI-14-C Multiple Signaling Command in one PDU, Data Truncated, BR/EDR, Connection Request - L2CAP/COS/CED/BI-15-C Multiple Signaling Command in one PDU, Data Truncated, BR/EDR, Disconnection Request The test procedure defined in L2CAP.TS.p39 for both tests is: 1. The Lower Tester sends a C-frame to the IUT with PDU Length set to 8 and Channel ID set to the correct signaling channel for the logical link. The Information payload contains one L2CAP_ECHO_REQ packet with Data Length set to 0 with 0 octets of echo data and one command packet and Data Length set as specified in Table 4.6 and the correct command data. 2. The IUT sends an L2CAP_ECHO_RSP PDU to the Lower Tester. 3. Perform alternative 3A, 3B, 3C, or 3D depending on the IUT’s response. Alternative 3A (IUT terminates the link): 3A.1 The IUT terminates the link. 3A.2 The test ends with a Pass verdict. Alternative 3B (IUT discards the frame): 3B.1 The IUT does not send a reply to the Lower Tester. Alternative 3C (IUT rejects PDU): 3C.1 The IUT sends an L2CAP_COMMAND_REJECT_RSP PDU to the Lower Tester. Alternative 3D (Any other IUT response): 3D.1 The Upper Tester issues a warning and the test ends. 4. The Lower Tester sends a C-frame to the IUT with PDU Length set to 4 and Channel ID set to the correct signaling channel for the logical link. The Information payload contains Data Length set to 0 with an L2CAP_ECHO_REQ packet with 0 octets of echo data. 5. The IUT sends an L2CAP_ECHO_RSP PDU to the Lower Tester. With expected outcome: In Steps 2 and 5, the IUT responds with an L2CAP_ECHO_RSP. In Step 3A.1, the IUT terminates the link. In Step 3B.1, the IUT does not send a reply to the Lower Tester. In Step 3C.1, the IUT rejects the PDU. In Step 3D.1, the IUT sends any valid response. Currently PTS fails with the following logs: Failed to receive ECHO RESPONSE. And HCI logs: > ACL Data RX: Handle 11 flags 0x02 dlen 20 L2CAP: Information Response (0x0b) ident 2 len 12 Type: Fixed channels supported (0x0003) Result: Success (0x0000) Channels: 0x000000000000002e L2CAP Signaling (BR/EDR) Connectionless reception AMP Manager Protocol L2CAP Signaling (LE) > ACL Data RX: Handle 11 flags 0x02 dlen 13 frame too long 08 01 00 00 08 02 01 00 aa ......... Cc: stable@vger.kernel.org Signed-off-by: Frédéric Danis Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/l2cap_core.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index f1c4b8bd7a8b..5ca7ac43c58d 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -7539,8 +7539,24 @@ void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) if (skb->len > len) { BT_ERR("Frame is too long (len %u, expected len %d)", skb->len, len); + /* PTS test cases L2CAP/COS/CED/BI-14-C and BI-15-C + * (Multiple Signaling Command in one PDU, Data + * Truncated, BR/EDR) send a C-frame to the IUT with + * PDU Length set to 8 and Channel ID set to the + * correct signaling channel for the logical link. + * The Information payload contains one L2CAP_ECHO_REQ + * packet with Data Length set to 0 with 0 octets of + * echo data and one invalid command packet due to + * data truncated in PDU but present in HCI packet. + * + * Shorter the socket buffer to the PDU length to + * allow to process valid commands from the PDU before + * setting the socket unreliable. + */ + skb->len = len; + l2cap_recv_frame(conn, skb); l2cap_conn_unreliable(conn, ECOMM); - goto drop; + goto unlock; } /* Append fragment into frame (with header) */ From 875db86e1ec75fe633f1e85ed2f92c731cdbf760 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 15 Apr 2025 09:15:19 -0700 Subject: [PATCH 2/2] Bluetooth: vhci: Avoid needless snprintf() calls Avoid double-copying of string literals. Use a "const char *" for each string instead of copying from .rodata into stack and then into the skb. We can go directly from .rodata to the skb. This also works around a Clang bug (that has since been fixed[1]). Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202401250927.1poZERd6-lkp@intel.com/ Fixes: ab4e4380d4e1 ("Bluetooth: Add vhci devcoredump support") Link: https://github.com/llvm/llvm-project/commit/ea2e66aa8b6e363b89df66dc44275a0d7ecd70ce [1] Cc: stable@vger.kernel.org Signed-off-by: Kees Cook Reviewed-by: Nathan Chancellor Reviewed-by: Josh Poimboeuf Signed-off-by: Luiz Augusto von Dentz --- drivers/bluetooth/hci_vhci.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/bluetooth/hci_vhci.c b/drivers/bluetooth/hci_vhci.c index a51935d37e5d..59f4d7bdffdc 100644 --- a/drivers/bluetooth/hci_vhci.c +++ b/drivers/bluetooth/hci_vhci.c @@ -289,18 +289,18 @@ static void vhci_coredump(struct hci_dev *hdev) static void vhci_coredump_hdr(struct hci_dev *hdev, struct sk_buff *skb) { - char buf[80]; + const char *buf; - snprintf(buf, sizeof(buf), "Controller Name: vhci_ctrl\n"); + buf = "Controller Name: vhci_ctrl\n"; skb_put_data(skb, buf, strlen(buf)); - snprintf(buf, sizeof(buf), "Firmware Version: vhci_fw\n"); + buf = "Firmware Version: vhci_fw\n"; skb_put_data(skb, buf, strlen(buf)); - snprintf(buf, sizeof(buf), "Driver: vhci_drv\n"); + buf = "Driver: vhci_drv\n"; skb_put_data(skb, buf, strlen(buf)); - snprintf(buf, sizeof(buf), "Vendor: vhci\n"); + buf = "Vendor: vhci\n"; skb_put_data(skb, buf, strlen(buf)); }