From 092c6a605cbd6414ef499834c2e0da69c2c3388e Mon Sep 17 00:00:00 2001 From: Doruk Tan Ozturk Date: Sat, 11 Jul 2026 14:36:51 +0200 Subject: [PATCH] nfc: port100: reject frames whose declared length exceeds the received data port100_recv_response() passes the URB transfer buffer to port100_rx_frame_is_valid(), which checksums le16_to_cpu(frame->datalen) bytes of frame->data. datalen is a 16-bit field supplied by the device and is never checked against the number of bytes actually received (urb->actual_length), so a device reporting a datalen larger than the received frame makes port100_data_checksum() read out of bounds past the transfer buffer. Reject a response whose declared frame size does not fit the received length before validating it. Found by 0sec (https://0sec.ai) using automated source analysis; the missing bound is evident from source. Compile-tested. Fixes: 562d4d59b8a1 ("NFC: Sony Port-100 Series driver") Cc: stable@vger.kernel.org Assisted-by: 0sec:claude-opus-4-8 Signed-off-by: Doruk Tan Ozturk Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260711123651.32595-1-doruk@0sec.ai Signed-off-by: David Heidelberg --- drivers/nfc/port100.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/nfc/port100.c b/drivers/nfc/port100.c index b613f5e2fd57..e769a30b8b5c 100644 --- a/drivers/nfc/port100.c +++ b/drivers/nfc/port100.c @@ -636,6 +636,13 @@ static void port100_recv_response(struct urb *urb) in_frame = dev->in_urb->transfer_buffer; + if (urb->actual_length < PORT100_FRAME_HEADER_LEN || + urb->actual_length < port100_rx_frame_size(in_frame)) { + nfc_err(&dev->interface->dev, "Received a truncated frame\n"); + cmd->status = -EIO; + goto sched_wq; + } + if (!port100_rx_frame_is_valid(in_frame)) { nfc_err(&dev->interface->dev, "Received an invalid frame\n"); cmd->status = -EIO;