vhost: check log mmap offset and size overflow

vhost_user_set_log_base() is a message handler that is
called to handle the VHOST_USER_SET_LOG_BASE message.
Its payload contains a 64 bit size and offset. Both are
added up and used as a size when calling mmap().

There is no integer overflow check. If an integer overflow
occurs a smaller memory map would be created than
requested. Since the returned mapping is mapped as writable
and used for logging, a memory corruption could occur.

CVE-2020-10722
Fixes: fbc4d248b198 ("vhost: fix offset while mmaping log base address")
Cc: stable@dpdk.org

Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Xiaolong Ye <xiaolong.ye@intel.com>
Reviewed-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
This commit is contained in:
Maxime Coquelin 2020-05-18 14:16:59 +01:00 committed by David Marchand
parent cfacbcb5a2
commit 3ae4beb079

View File

@ -2068,10 +2068,10 @@ vhost_user_set_log_base(struct virtio_net **pdev, struct VhostUserMsg *msg,
size = msg->payload.log.mmap_size;
off = msg->payload.log.mmap_offset;
/* Don't allow mmap_offset to point outside the mmap region */
if (off > size) {
/* Check for mmap size and offset overflow. */
if (off >= -size) {
VHOST_LOG_CONFIG(ERR,
"log offset %#"PRIx64" exceeds log size %#"PRIx64"\n",
"log offset %#"PRIx64" and log size %#"PRIx64" overflow\n",
off, size);
return RTE_VHOST_MSG_RESULT_ERR;
}