Wind River Support Network

Description

In the Linux kernel, the following vulnerability has been resolved:  Input: usbtouchscreen - clamp NEXIO data_len/x_len to URB buffer size  nexio_read_data() pulls data_len and x_len from a packed __be16 header in the device's interrupt packet and then walks packet->data[0..x_len) and packet->data[x_len..data_len) comparing each byte against a threshold.  Both fields are 16-bit on the wire (max 65535).  The existing adjustments shave at most 0x100 / 0x80 off, so the loop bound can still reach roughly 0xfeff.  The URB transfer buffer for NEXIO is rept_size (1024) bytes from usb_alloc_coherent(), with the first 7 occupied by the packed header — so packet->data[] has 1017 valid bytes.  read_data() callbacks are not given urb->actual_length, and nothing else bounds the walk.  A device that lies about its length can get a ~64 KiB out-of-bounds read past the coherent DMA allocation.  The first index whose byte exceeds NEXIO_THRESHOLD lands in begin_x / begin_y and from there into the reported touch coordinates, so adjacent kernel memory contents leak to userspace as ABS_X / ABS_Y events.  Far enough out, the read can also hit an unmapped page and fault.  Fix this all by clamping data_len to the buffer's data[] capacity and x_len to data_len.