From: Xiubo Li xiubli@redhat.com
commit e027253c4b77d395798600a90b6a96fe4adf4d5e upstream.
The fallocate will try to clear the suid/sgid if a unprevileged user changed the file.
There is no POSIX item requires that we should clear the suid/sgid in fallocate code path but this is the default behaviour for most of the filesystems and the VFS layer. And also the same for the write code path, which have already support it.
And also we need to update the time stamps since the fallocate will change the file contents.
Cc: stable@vger.kernel.org Link: https://tracker.ceph.com/issues/58054 Signed-off-by: Xiubo Li xiubli@redhat.com Reviewed-by: Jeff Layton jlayton@kernel.org Signed-off-by: Ilya Dryomov idryomov@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ceph/file.c | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -2084,6 +2084,9 @@ static long ceph_fallocate(struct file * loff_t endoff = 0; loff_t size;
+ dout("%s %p %llx.%llx mode %x, offset %llu length %llu\n", __func__, + inode, ceph_vinop(inode), mode, offset, length); + if (mode != (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) return -EOPNOTSUPP;
@@ -2124,6 +2127,10 @@ static long ceph_fallocate(struct file * if (ret < 0) goto unlock;
+ ret = file_modified(file); + if (ret) + goto put_caps; + filemap_invalidate_lock(inode->i_mapping); ceph_zero_pagecache_range(inode, offset, length); ret = ceph_zero_objects(inode, offset, length); @@ -2139,6 +2146,7 @@ static long ceph_fallocate(struct file * } filemap_invalidate_unlock(inode->i_mapping);
+put_caps: ceph_put_cap_refs(ci, got); unlock: inode_unlock(inode);