CVE-2026-53224

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

sctp: validate embedded INIT chunk and address list lengths in cookie

sctp_unpack_cookie() only checked that the embedded INIT chunk length

did not exceed the remaining cookie payload, but did not ensure that the

INIT chunk is large enough to contain a complete INIT header.

A malformed COOKIE_ECHO can therefore carry a truncated INIT chunk whose

length field is smaller than sizeof(struct sctp_init_chunk). Later,

sctp_process_init() accesses INIT parameters unconditionally, which may

lead to out-of-bounds reads.

In addition, raw_addr_list_len is not fully validated against the

remaining cookie payload. When cookie authentication is disabled, an

attacker can supply an oversized raw_addr_list_len and cause

sctp_raw_to_bind_addrs() to read beyond the end of the cookie. The

address parser also lacks sufficient bounds checks for parameter headers

and lengths, allowing malformed address parameters to trigger

out-of-bounds reads.

Fix this by:

- requiring the embedded INIT chunk length to be at least sizeof(struct

sctp_init_chunk);

- validating that the INIT chunk and raw address list together fit

within the cookie payload;

- verifying sufficient data exists for each address parameter header and

payload before parsing it.

Note that sctp_verify_init() must be called after sctp_unpack_cookie()

and before sctp_process_init() when cookie authentication is disabled.

This will be addressed in a separate patch.