path: root/fs
diff options
authorMike Kravetz <mike.kravetz@oracle.com>2021-05-22 17:42:11 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-05-22 15:09:07 -1000
commite32905e57358fdfb82f9de024534f205b3af7dac (patch)
tree8fd4c5a222e4e776149934322b08c623041f2b45 /fs
parent1b6d63938a9d868df01d5bc6e2da212133121b8d (diff)
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')
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));
if (!truncate_op) {

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