In the Linux kernel, the following vulnerability has been resolved: fs/namespace: fix reference leak in grab_requested_mnt_ns lookup_mnt_ns() already takes a reference on mnt_ns. grab_requested_mnt_ns() doesn't need to take an extra reference.
https://git.kernel.org/stable/c/fe256e59b8e7f126b2464ee32bd9fee131f0a883
https://git.kernel.org/stable/c/7b6dcd9bfd869eee7693e45b1817dac8c56e5f86
https://git.kernel.org/stable/c/4a16b2a0c1f033f95f5d0b98b9e40e8bf7c4c2c5