Converting a file handle to a dentry can be done call after the inode unlink. This means that __fh_to_dentry() requires an extra check to verify the number of links is not 0.
The issue can be easily reproduced using xfstest generic/426, which does something like: name_to_handle_at(&fh) echo 3 > /proc/sys/vm/drop_caches unlink() open_by_handle_at(&fh) The call to open_by_handle_at() should fail, as the file doesn't exist anymore. Cc: sta...@vger.kernel.org Link: http://tracker.ceph.com/issues/19958 Signed-off-by: Luis Henriques <lhenriq...@suse.com> --- fs/ceph/export.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/ceph/export.c b/fs/ceph/export.c index e8f11fa565c5..7df550c13d7f 100644 --- a/fs/ceph/export.c +++ b/fs/ceph/export.c @@ -91,6 +91,10 @@ static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino) ceph_mdsc_put_request(req); if (!inode) return ERR_PTR(-ESTALE); + if (inode->i_nlink == 0) { + iput(inode); + return ERR_PTR(-ESTALE); + } } return d_obtain_alias(inode);
