CVE-2026-72413

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

sctp: fix err_chunk memory leaks in INIT handling

When sctp_verify_init() encounters unrecognized parameters, it allocates an
err_chunk to report them. However, this chunk is leaked in several code
paths:

1. In sctp_sf_do_5_1B_init(), if security_sctp_assoc_request() fails after
   sctp_verify_init() has populated err_chunk, the function returns
   immediately without freeing it.

2. In sctp_sf_do_unexpected_init(), the same leak occurs on the
   security_sctp_assoc_request() failure path.

3. In sctp_sf_do_unexpected_init(), on the success path after copying
   unrecognized parameters to the INIT-ACK, the function returns without
   freeing err_chunk, unlike sctp_sf_do_5_1B_init() which properly frees
   it.

Fix all three leaks by adding sctp_chunk_free(err_chunk) calls before
returning in the error paths and on the success path in
sctp_sf_do_unexpected_init().