Description: net/sched: cls_u32: fix netns refcount changes in u32_change()
References:
 https://www.openwall.com/lists/oss-security/2022/05/18/2
Notes:
 carnil> Introduced in 35c55fc156d8 ("cls_u32: use tcf_exts_get_net()
 carnil> before call_rcu()" in 4.14.
Bugs:
upstream: released (5.18-rc4) [3db09e762dc79584a69c10d74a6b98f89a9979f8]
5.10-upstream-stable: released (5.10.113) [43ce33a68e2bcc431097e1075aad5393d0bf53ba]
4.19-upstream-stable: released (4.19.241) [75b0cc7904da7b40c6e8f2cf3ec4223b292b1184]
4.9-upstream-stable: N/A "Vulnerable code not present"
sid: released (5.17.6-1)
5.10-bullseye-security: released (5.10.113-1)
4.19-buster-security: released (4.19.249-1)
4.9-stretch-security: N/A "Vulnerable code not present"