diff options
| author | Andrea Arcangeli <aarcange@redhat.com> | 2018-11-30 14:09:37 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-08 12:59:08 +0100 |
| commit | 4ce337622f2bbc0df61b0b76aa60388f5def5646 (patch) | |
| tree | 666bb0db5720cba8bc4085d185dd6bc3d16cb422 /drivers | |
| parent | 6e44dd02c95508f6df5eca4d46adbb75233ea181 (diff) | |
userfaultfd: shmem: add i_size checks
commit e2a50c1f64145a04959df2442305d57307e5395a upstream.
With MAP_SHARED: recheck the i_size after taking the PT lock, to
serialize against truncate with the PT lock. Delete the page from the
pagecache if the i_size_read check fails.
With MAP_PRIVATE: check the i_size after the PT lock before mapping
anonymous memory or zeropages into the MAP_PRIVATE shmem mapping.
A mostly irrelevant cleanup: like we do the delete_from_page_cache()
pagecache removal after dropping the PT lock, the PT lock is a spinlock
so drop it before the sleepable page lock.
Link: http://lkml.kernel.org/r/20181126173452.26955-5-aarcange@redhat.com
Fixes: 4c27fe4c4c84 ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Hugh Dickins <hughd@google.com>
Reported-by: Jann Horn <jannh@google.com>
Cc: <stable@vger.kernel.org>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
0 files changed, 0 insertions, 0 deletions