[PATCH 5.5 218/257] NFS: Fix a page leak in nfs_destroy_unlinked_subrequests()

From: Greg Kroah-Hartman
Date: Thu Apr 16 2020 - 10:01:11 EST


From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>

commit add42de31721fa29ed77a7ce388674d69f9d31a4 upstream.

When we detach a subrequest from the list, we must also release the
reference it holds to the parent.

Fixes: 5b2b5187fa85 ("NFS: Fix nfs_page_group_destroy() and nfs_lock_and_join_requests() race cases")
Cc: stable@xxxxxxxxxxxxxxx # v4.14+
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/nfs/write.c | 1 +
1 file changed, 1 insertion(+)

--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -441,6 +441,7 @@ nfs_destroy_unlinked_subrequests(struct
}

subreq->wb_head = subreq;
+ nfs_release_request(old_head);

if (test_and_clear_bit(PG_INODE_REF, &subreq->wb_flags)) {
nfs_release_request(subreq);