Description: tun: avoid double free in tun_free_netdev
References:
 https://bugzilla.redhat.com/show_bug.cgi?id=2156322
Notes:
Bugs:
upstream: released (5.16-rc7) [158b515f703e75e7d68289bf4d98c664e1d632df]
6.1-upstream-stable: N/A "Fixed before branching point"
5.10-upstream-stable: released (5.10.136) [a01a4e9f5dc93335c716fa4023b1901956e8c904]
4.19-upstream-stable: released (4.19.280) [8eb43d635950e27c29f1e9e49a23b31637f37757]
sid: released (5.15.15-1)
5.10-bullseye-security: released (5.10.136-1)
4.19-buster-security: released (4.19.282-1)