CVE-2026-72413sctp: fix err_chunk memory leaks in INIT handling

Official description

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().

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/a8e6a839c0e7ca1da752faaab51e2eafb17483a4
• https://git.kernel.org/stable/c/43ddbcdc0ed74a8fba4aff5e623ace8135411b93
• https://git.kernel.org/stable/c/6acedac7a14af71cfe25024ead28e16a070899e4
• https://git.kernel.org/stable/c/1cae40d423a2042c7970f29c00028951ec20db8a
• https://git.kernel.org/stable/c/94f55994e19e8f0676990b9d5015b58ab6a97e00
• https://git.kernel.org/stable/c/9f58a0a4d6c2ed5d341bba64f058f15d1b0c36f2