c4c0e236be
In usb-linux.c:usb_host_handle_control, we pass a 1024-byte buffer and length to the kernel. However, the length was provided by the caller of dev->handle_packet, and is not checked, so the kernel might provide too much data and overflow our buffer. For example, hw/usb-uhci.c could set the length to 2047. hw/usb-ohci.c looks like it might go up to 4096 or 8192. This causes a qemu crash, as reported here: http://www.mail-archive.com/kvm@vger.kernel.org/msg18447.html This patch increases the usb-linux.c buffer size to 2048 to fix the specific device reported, and adds a check to avoid the overflow in any case. Signed-off-by: Jim Paris <jim@jtan.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Read the documentation in qemu-doc.html. Fabrice Bellard.