From 9f4e63491ba7ae2f7a537bb98a337f4dcd4e1c54 Mon Sep 17 00:00:00 2001 From: Raphael Norwitz Date: Mon, 17 Jan 2022 04:12:31 +0000 Subject: [PATCH] libvhost-user: Add vu_add_mem_reg input validation Today if multiple FDs are sent from the VMM to the backend in a VHOST_USER_ADD_MEM_REG message, one FD will be mapped and the remaining FDs will be leaked. Therefore if multiple FDs are sent we report an error and fail the operation, closing all FDs in the message. Likewise in case the VMM sends a message with a size less than that of a memory region descriptor, we add a check to gracefully report an error and fail the operation rather than crashing. Signed-off-by: Raphael Norwitz Message-Id: <20220117041050.19718-3-raphael.norwitz@nutanix.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: David Hildenbrand --- subprojects/libvhost-user/libvhost-user.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c index b09b1c269e..1a8fc9d600 100644 --- a/subprojects/libvhost-user/libvhost-user.c +++ b/subprojects/libvhost-user/libvhost-user.c @@ -690,6 +690,21 @@ vu_add_mem_reg(VuDev *dev, VhostUserMsg *vmsg) { VuDevRegion *dev_region = &dev->regions[dev->nregions]; void *mmap_addr; + if (vmsg->fd_num != 1) { + vmsg_close_fds(vmsg); + vu_panic(dev, "VHOST_USER_ADD_MEM_REG received %d fds - only 1 fd " + "should be sent for this message type", vmsg->fd_num); + return false; + } + + if (vmsg->size < VHOST_USER_MEM_REG_SIZE) { + close(vmsg->fds[0]); + vu_panic(dev, "VHOST_USER_ADD_MEM_REG requires a message size of at " + "least %d bytes and only %d bytes were received", + VHOST_USER_MEM_REG_SIZE, vmsg->size); + return false; + } + /* * If we are in postcopy mode and we receive a u64 payload with a 0 value * we know all the postcopy client bases have been received, and we