kernel/linux.git/drivers/net/usb/ipheth.c, branch v6.12.80

usbnet: ipheth: document scope of NCM implementation

2025-02-17T09:05:16+00:00

commit be154b598fa54136e2be17d6dd13c8a8bc0078ce upstream. Clarify that the "NCM" implementation in `ipheth` is very limited, as iOS devices aren't compatible with the CDC NCM specification in regular tethering mode. For a standards-compliant implementation, one shall turn to the `cdc_ncm` module. Cc: stable@vger.kernel.org # 6.5.x Signed-off-by: Foster Snowhill Reviewed-by: Jakub Kicinski Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

usbnet: ipheth: fix DPE OoB read

2025-02-17T09:05:16+00:00

commit ee591f2b281721171896117f9946fced31441418 upstream. Fix an out-of-bounds DPE read, limit the number of processed DPEs to the amount that fits into the fixed-size NDP16 header. Fixes: a2d274c62e44 ("usbnet: ipheth: add CDC NCM support") Cc: stable@vger.kernel.org Signed-off-by: Foster Snowhill Reviewed-by: Jakub Kicinski Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

usbnet: ipheth: break up NCM header size computation

2025-02-17T09:05:16+00:00

commit efcbc678a14be268040ffc1fa33c98faf2d55141 upstream. Originally, the total NCM header size was computed as the sum of two vaguely labelled constants. While accurate, it wasn't particularly clear where they were coming from. Use sizes of existing NCM structs where available. Define the total NDP16 size based on the maximum amount of DPEs that can fit into the iOS-specific fixed-size header. This change does not fix any particular issue. Rather, it introduces intermediate constants that will simplify subsequent commits. It should also make it clearer for the reader where the constant values come from. Cc: stable@vger.kernel.org # 6.5.x Signed-off-by: Foster Snowhill Reviewed-by: Jakub Kicinski Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

usbnet: ipheth: refactor NCM datagram loop

2025-02-17T09:05:16+00:00

commit 2a9a196429e98fcc64078366c2679bc40aba5466 upstream. Introduce an rx_error label to reduce repetitions in the header signature checks. Store wDatagramIndex and wDatagramLength after endianness conversion to avoid repeated le16_to_cpu() calls. Rewrite the loop to return on a null trailing DPE, which is required by the CDC NCM spec. In case it is missing, fall through to rx_error. This change does not fix any particular issue. Its purpose is to simplify a subsequent commit that fixes a potential OoB read by limiting the maximum amount of processed DPEs. Cc: stable@vger.kernel.org # 6.5.x Signed-off-by: Foster Snowhill Reviewed-by: Jakub Kicinski Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

usbnet: ipheth: check that DPE points past NCM header

2025-02-17T09:05:16+00:00

commit 429fa68b58cefb9aa9de27e4089637298b46b757 upstream. By definition, a DPE points at the start of a network frame/datagram. Thus it makes no sense for it to point at anything that's part of the NCM header. It is not a security issue, but merely an indication of a malformed DPE. Enforce that all DPEs point at the data portion of the URB, past the NCM header. Fixes: a2d274c62e44 ("usbnet: ipheth: add CDC NCM support") Cc: stable@vger.kernel.org Signed-off-by: Foster Snowhill Reviewed-by: Jakub Kicinski Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

usbnet: ipheth: use static NDP16 location in URB

2025-02-17T09:05:16+00:00

commit 86586dcb75cb8fd062a518aca8ee667938b91efb upstream. Original code allowed for the start of NDP16 to be anywhere within the URB based on the `wNdpIndex` value in NTH16. Only the start position of NDP16 was checked, so it was possible for even the fixed-length part of NDP16 to extend past the end of URB, leading to an out-of-bounds read. On iOS devices, the NDP16 header always directly follows NTH16. Rely on and check for this specific format. This, along with NCM-specific minimal URB length check that already exists, will ensure that the fixed-length part of NDP16 plus a set amount of DPEs fit within the URB. Note that this commit alone does not fully address the OoB read. The limit on the amount of DPEs needs to be enforced separately. Fixes: a2d274c62e44 ("usbnet: ipheth: add CDC NCM support") Cc: stable@vger.kernel.org Signed-off-by: Foster Snowhill Reviewed-by: Jakub Kicinski Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

usbnet: ipheth: fix possible overflow in DPE length check

2025-02-17T09:05:15+00:00

commit c219427ed296f94bb4b91d08626776dc7719ee27 upstream. Originally, it was possible for the DPE length check to overflow if wDatagramIndex + wDatagramLength > U16_MAX. This could lead to an OoB read. Move the wDatagramIndex term to the other side of the inequality. An existing condition ensures that wDatagramIndex < urb->actual_length. Fixes: a2d274c62e44 ("usbnet: ipheth: add CDC NCM support") Cc: stable@vger.kernel.org Signed-off-by: Foster Snowhill Reviewed-by: Jakub Kicinski Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

usbnet: ipheth: fix carrier detection in modes 1 and 4

2024-08-09T12:54:21+00:00

Apart from the standard "configurations", "interfaces" and "alternate interface settings" in USB, iOS devices also have a notion of "modes". In different modes, the device exposes a different set of available configurations. Depending on the iOS version, and depending on the current mode, the length and contents of the carrier state control message differs: * 1 byte (seen on iOS 4.2.1, 8.4): * 03: carrier off (mode 0) * 04: carrier on (mode 0) * 3 bytes (seen on iOS 10.3.4, 15.7.6): * 03 03 03: carrier off (mode 0) * 04 04 03: carrier on (mode 0) * 4 bytes (seen on iOS 16.5, 17.6): * 03 03 03 00: carrier off (mode 0) * 04 03 03 00: carrier off (mode 1) * 06 03 03 00: carrier off (mode 4) * 04 04 03 04: carrier on (mode 0 and 1) * 06 04 03 04: carrier on (mode 4) Before this change, the driver always used the first byte of the response to determine carrier state. From this larger sample, the first byte seems to indicate the number of available USB configurations in the current mode (with the exception of the default mode 0), and in some cases (namely mode 1 and 4) does not correlate with the carrier state. Previous logic erroneously counted `04 03 03 00` as "carrier on" and `06 04 03 04` as "carrier off" on iOS versions that support mode 1 and mode 4 respectively. Only modes 0, 1 and 4 expose the USB Ethernet interfaces necessary for the ipheth driver. Check the second byte of the control message where possible, and fall back to checking the first byte on older iOS versions. Signed-off-by: Foster Snowhill Tested-by: Georgi Valkov Signed-off-by: David S. Miller

usbnet: ipheth: do not stop RX on failing RX callback

2024-08-09T12:54:21+00:00

RX callbacks can fail for multiple reasons: * Payload too short * Payload formatted incorrecly (e.g. bad NCM framing) * Lack of memory None of these should cause the driver to seize up. Make such failures non-critical and continue processing further incoming URBs. Signed-off-by: Foster Snowhill Signed-off-by: David S. Miller

usbnet: ipheth: drop RX URBs with no payload

2024-08-09T12:54:20+00:00

On iPhone 15 Pro Max one can observe periodic URBs with no payload on the "bulk in" (RX) endpoint. These don't seem to do anything meaningful. Reproduced on iOS 17.5.1 and 17.6. This behaviour isn't observed on iPhone 11 on the same iOS version. The nature of these zero-length URBs is so far unknown. Drop RX URBs with no payload. Signed-off-by: Foster Snowhill Signed-off-by: David S. Miller