Revision c300aa64ddf57d9c5d9c898a64b36877345dd4a9 authored by Andy Honig on 11 March 2013, 16:34:52 UTC, committed by Marcelo Tosatti on 19 March 2013, 17:17:31 UTC
If the guest sets the GPA of the time_page so that the request to update the time straddles a page then KVM will write onto an incorrect page. The write is done byusing kmap atomic to get a pointer to the page for the time structure and then performing a memcpy to that page starting at an offset that the guest controls. Well behaved guests always provide a 32-byte aligned address, however a malicious guest could use this to corrupt host kernel memory. Tested: Tested against kvmclock unit test. Signed-off-by: Andrew Honig <ahonig@google.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
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Kconfig
config NILFS2_FS
tristate "NILFS2 file system support"
select CRC32
help
NILFS2 is a log-structured file system (LFS) supporting continuous
snapshotting. In addition to versioning capability of the entire
file system, users can even restore files mistakenly overwritten or
destroyed just a few seconds ago. Since this file system can keep
consistency like conventional LFS, it achieves quick recovery after
system crashes.
NILFS2 creates a number of checkpoints every few seconds or per
synchronous write basis (unless there is no change). Users can
select significant versions among continuously created checkpoints,
and can change them into snapshots which will be preserved for long
periods until they are changed back to checkpoints. Each
snapshot is mountable as a read-only file system concurrently with
its writable mount, and this feature is convenient for online backup.
Some features including atime, extended attributes, and POSIX ACLs,
are not supported yet.
To compile this file system support as a module, choose M here: the
module will be called nilfs2. If unsure, say N.
Computing file changes ...
