https://github.com/torvalds/linux
Revision e2a50c1f64145a04959df2442305d57307e5395a authored by Andrea Arcangeli on 30 November 2018, 22:09:37 UTC, committed by Linus Torvalds on 30 November 2018, 22:56:14 UTC
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>
1 parent 29ec906
Tip revision: e2a50c1f64145a04959df2442305d57307e5395a authored by Andrea Arcangeli on 30 November 2018, 22:09:37 UTC
userfaultfd: shmem: add i_size checks
userfaultfd: shmem: add i_size checks
Tip revision: e2a50c1
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| .cocciconfig | -rw-r--r-- | 59 bytes |
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| MAINTAINERS | -rw-r--r-- | 472.8 KB |
| Makefile | -rw-r--r-- | 59.7 KB |
| README | -rw-r--r-- | 727 bytes |
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