pn532_receive_buf() appends every incoming byte to dev->recv_skb and only resets the buffer after pn532_uart_rx_is_frame() recognizes a complete frame. A continuous stream of bytes without a valid PN532 frame header therefore keeps growing the skb until skb_put_u8() hits the tail limit. Drop the accumulated partial frame once the fixed receive buffer is full so malformed UART traffic cannot grow the skb past PN532_UART_SKB_BUFF_LEN. Signed-off-by: Pengpeng Hou --- drivers/nfc/pn533/uart.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/nfc/pn533/uart.c b/drivers/nfc/pn533/uart.c index 6d2f520a5bc8..1b82b7b2a5fa 100644 --- a/drivers/nfc/pn533/uart.c +++ b/drivers/nfc/pn533/uart.c @@ -211,6 +211,9 @@ static size_t pn532_receive_buf(struct serdev_device *serdev, timer_delete(&dev->cmd_timeout); for (i = 0; i < count; i++) { + if (unlikely(!skb_tailroom(dev->recv_skb))) + skb_trim(dev->recv_skb, 0); + skb_put_u8(dev->recv_skb, *data++); if (!pn532_uart_rx_is_frame(dev->recv_skb)) continue; -- 2.50.1 (Apple Git-155)