5.4-stable review patch. If anyone has any objections, please let me know.
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From: Halil Pasic pasic@linux.ibm.com
commit fbd3039a64b01b769040677c4fc68badeca8e3b2 upstream.
As per virtio spec the fields cols and rows are specified as little endian. Although there is no legacy interface requirement that would state that cols and rows need to be handled as native endian when legacy interface is used, unlike for the fields of the adjacent struct virtio_console_control, I decided to err on the side of caution based on some non-conclusive virtio spec repo archaeology and opt for using virtio16_to_cpu() much like for virtio_console_control.event. Strictly by the letter of the spec virtio_le_to_cpu() would have been sufficient. But when the legacy interface is not used, it boils down to the same.
And when using the legacy interface, the device formatting these as little endian when the guest is big endian would surprise me more than it using guest native byte order (which would make it compatible with the current implementation). Nevertheless somebody trying to implement the spec following it to the letter could end up forcing little endian byte order when the legacy interface is in use. So IMHO this ultimately needs a judgement call by the maintainers.
Fixes: 8345adbf96fc1 ("virtio: console: Accept console size along with resize control message") Signed-off-by: Halil Pasic pasic@linux.ibm.com Cc: stable@vger.kernel.org # v2.6.35+ Message-Id: 20250322002954.3129282-1-pasic@linux.ibm.com Signed-off-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/char/virtio_console.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
--- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -1619,8 +1619,8 @@ static void handle_control_message(struc break; case VIRTIO_CONSOLE_RESIZE: { struct { - __u16 rows; - __u16 cols; + __virtio16 rows; + __virtio16 cols; } size;
if (!is_console_port(port)) @@ -1628,7 +1628,8 @@ static void handle_control_message(struc
memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt), sizeof(size)); - set_console_size(port, size.rows, size.cols); + set_console_size(port, virtio16_to_cpu(vdev, size.rows), + virtio16_to_cpu(vdev, size.cols));
port->cons.hvc->irq_requested = 1; resize_console(port);