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| author | Mike Kravetz <mike.kravetz@oracle.com> | 2021-05-23 03:42:11 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-05-23 04:09:07 +0300 |
| commit | e32905e57358fdfb82f9de024534f205b3af7dac (patch) | |
| tree | 8fd4c5a222e4e776149934322b08c623041f2b45 /fs/hugetlbfs | |
| parent | 1b6d63938a9d868df01d5bc6e2da212133121b8d (diff) | |
| download | linux-e32905e57358fdfb82f9de024534f205b3af7dac.tar.xz | |
userfaultfd: hugetlbfs: fix new flag usage in error path
In commit d6995da31122 ("hugetlb: use page.private for hugetlb specific
page flags") the use of PagePrivate to indicate a reservation count
should be restored at free time was changed to the hugetlb specific flag
HPageRestoreReserve. Changes to a userfaultfd error path as well as a
VM_BUG_ON() in remove_inode_hugepages() were overlooked.
Users could see incorrect hugetlb reserve counts if they experience an
error with a UFFDIO_COPY operation. Specifically, this would be the
result of an unlikely copy_huge_page_from_user error. There is not an
increased chance of hitting the VM_BUG_ON.
Link: https://lkml.kernel.org/r/20210521233952.236434-1-mike.kravetz@oracle.com
Fixes: d6995da31122 ("hugetlb: use page.private for hugetlb specific page flags")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Mina Almasry <almasry.mina@google.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/hugetlbfs')
| -rw-r--r-- | fs/hugetlbfs/inode.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 9d9e0097c1d3..55efd3dd04f6 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -529,7 +529,7 @@ static void remove_inode_hugepages(struct inode *inode, loff_t lstart, * the subpool and global reserve usage count can need * to be adjusted. */ - VM_BUG_ON(PagePrivate(page)); + VM_BUG_ON(HPageRestoreReserve(page)); remove_huge_page(page); freed++; if (!truncate_op) { |