From aba30af07d4fe499b50209801eba9da8a815522f Mon Sep 17 00:00:00 2001 From: Pengpeng Hou Date: Sun, 5 Jul 2026 16:46:01 +0800 Subject: [PATCH] ALSA: usb-audio: caiaq: validate EP1 reply lengths usb_ep1_command_reply_dispatch() uses buf[0] as a command byte and then reads command-specific fixed items from the same URB buffer. Several paths use buf + 1, buf[1], buf[2], or buf + 3 without first proving that urb->actual_length contains those bytes. Add per-command length checks, use a payload length derived from the bytes after the command byte for the control-state copy, and reject short analog input payloads before the input helper reads fixed offsets from the EP1 reply. Signed-off-by: Pengpeng Hou Link: https://patch.msgid.link/20260705084601.56400-1-pengpeng@iscas.ac.cn Signed-off-by: Takashi Iwai --- sound/usb/caiaq/device.c | 17 ++++++++++++++--- sound/usb/caiaq/input.c | 6 ++++++ 2 files changed, 20 insertions(+), 3 deletions(-) diff --git a/sound/usb/caiaq/device.c b/sound/usb/caiaq/device.c index b20aae0caf60..a16e59248480 100644 --- a/sound/usb/caiaq/device.c +++ b/sound/usb/caiaq/device.c @@ -134,14 +134,22 @@ static void usb_ep1_command_reply_dispatch (struct urb* urb) struct device *dev = &urb->dev->dev; struct snd_usb_caiaqdev *cdev = urb->context; unsigned char *buf = urb->transfer_buffer; + unsigned int payload_len; + unsigned int copy_len; if (urb->status || !cdev) { dev_warn(dev, "received EP1 urb->status = %i\n", urb->status); return; } + if (urb->actual_length < 1) + return; + + payload_len = urb->actual_length - 1; switch(buf[0]) { case EP1_CMD_GET_DEVICE_INFO: + if (payload_len < sizeof(struct caiaq_device_spec)) + break; memcpy(&cdev->spec, buf+1, sizeof(struct caiaq_device_spec)); cdev->spec.fw_version = le16_to_cpu(cdev->spec.fw_version); dev_dbg(dev, "device spec (firmware %d): audio: %d in, %d out, " @@ -157,18 +165,21 @@ static void usb_ep1_command_reply_dispatch (struct urb* urb) wake_up(&cdev->ep1_wait_queue); break; case EP1_CMD_AUDIO_PARAMS: + if (payload_len < 1) + break; cdev->audio_parm_answer = buf[1]; wake_up(&cdev->ep1_wait_queue); break; case EP1_CMD_MIDI_READ: + if (urb->actual_length < 3 || urb->actual_length - 3 < buf[2]) + break; snd_usb_caiaq_midi_handle_input(cdev, buf[1], buf + 3, buf[2]); break; case EP1_CMD_READ_IO: if (cdev->chip.usb_id == USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AUDIO8DJ)) { - if (urb->actual_length > sizeof(cdev->control_state)) - urb->actual_length = sizeof(cdev->control_state); - memcpy(cdev->control_state, buf + 1, urb->actual_length); + copy_len = min_t(unsigned int, payload_len, sizeof(cdev->control_state)); + memcpy(cdev->control_state, buf + 1, copy_len); wake_up(&cdev->ep1_wait_queue); break; } diff --git a/sound/usb/caiaq/input.c b/sound/usb/caiaq/input.c index eabbf41fdfb2..8d924330c54c 100644 --- a/sound/usb/caiaq/input.c +++ b/sound/usb/caiaq/input.c @@ -203,6 +203,8 @@ static void snd_caiaq_input_read_analog(struct snd_usb_caiaqdev *cdev, switch (cdev->chip.usb_id) { case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_RIGKONTROL2): + if (len < 6) + return; snd_caiaq_input_report_abs(cdev, ABS_X, buf, 2); snd_caiaq_input_report_abs(cdev, ABS_Y, buf, 0); snd_caiaq_input_report_abs(cdev, ABS_Z, buf, 1); @@ -210,11 +212,15 @@ static void snd_caiaq_input_read_analog(struct snd_usb_caiaqdev *cdev, case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_RIGKONTROL3): case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_KORECONTROLLER): case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_KORECONTROLLER2): + if (len < 6) + return; snd_caiaq_input_report_abs(cdev, ABS_X, buf, 0); snd_caiaq_input_report_abs(cdev, ABS_Y, buf, 1); snd_caiaq_input_report_abs(cdev, ABS_Z, buf, 2); break; case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_TRAKTORKONTROLX1): + if (len < 16) + return; snd_caiaq_input_report_abs(cdev, ABS_HAT0X, buf, 4); snd_caiaq_input_report_abs(cdev, ABS_HAT0Y, buf, 2); snd_caiaq_input_report_abs(cdev, ABS_HAT1X, buf, 6);