virtio_console: refactor __send_to_port() buffer ownership

Modify __send_to_port() to take ownership of a struct port_buffer *
instead of a void * raw buffer.

Previously, put_chars() would pass a raw kmemdup'd buffer and free it
immediately after __send_to_port() returned. This caused a potential
Use-After-Free and data corruption if the virtqueue was shared with
nonblocking writers, as virtqueue_get_buf() might return an older
completed buffer, causing the newly added buffer to be kfree'd while the
host is still DMAing from it.

By transferring ownership of the allocated port_buffer to __send_to_port(),
we ensure that the exact buffer returned by the host is the one that gets
freed, resolving the memory lifecycle mismatch.

Signed-off-by: Sungho Bae <baver.bae@lge.com>
Link: https://patch.msgid.link/20260603183757.21587-2-baver.bae@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

0 files changed, 0 insertions, 0 deletions