In the Linux kernel, the following vulnerability has been resolved:

sctp: sysctl: auth_enable: avoid using current->nsproxy

As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:

- Inconsistency: getting info from the reader's/writer's netns vs only
  from the opener's netns.

- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
  (null-ptr-deref), e.g. when the current task is exiting, as spotted by
  syzbot [1] using acct(2).

The 'net' structure can be obtained from the table->data using
container_of().

Note that table->data could also be used directly, but that would
increase the size of this fix, while 'sctp.ctl_sock' still needs to be
retrieved from 'net' structure.

https://git.kernel.org/stable/c/15649fd5415eda664ef35780c2013adeb5d9c695

https://git.kernel.org/stable/c/1b67030d39f2b00f94ac1f0af11ba6657589e4d3

https://git.kernel.org/stable/c/7ec30c54f339c640aa7e49d7e9f7bbed6bd42bf6

https://git.kernel.org/stable/c/c184bc621e3cef03ac9ba81a50dda2dae6a21d36