memory: Revert "memory: accept mismatching sizes in memory_region_access_valid"
authorMichael S. Tsirkin <mst@redhat.com>
Wed, 10 Jun 2020 13:47:49 +0000 (09:47 -0400)
committerPaolo Bonzini <pbonzini@redhat.com>
Fri, 26 Jun 2020 10:45:30 +0000 (06:45 -0400)
commit5d971f9e672507210e77d020d89e0e89165c8fc9
tree5d965711aa2e719c8d3b26ab4aa0243dc73bd85f
parent4b7c06837ae0b1ff56473202a42e7e386f53d6db
memory: Revert "memory: accept mismatching sizes in memory_region_access_valid"

Memory API documentation documents valid .min_access_size and .max_access_size
fields and explains that any access outside these boundaries is blocked.

This is what devices seem to assume.

However this is not what the implementation does: it simply
ignores the boundaries unless there's an "accepts" callback.

Naturally, this breaks a bunch of devices.

Revert to the documented behaviour.

Devices that want to allow any access can just drop the valid field,
or add the impl field to have accesses converted to appropriate
length.

Cc: qemu-stable@nongnu.org
Reviewed-by: Richard Henderson <rth@twiddle.net>
Fixes: CVE-2020-13754
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1842363
Fixes: a014ed07bd5a ("memory: accept mismatching sizes in memory_region_access_valid")
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20200610134731.1514409-1-mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
memory.c