From: HanQuan Date: Mon, 13 Jul 2026 03:20:21 +0000 (+0000) Subject: sctp: fix auth_chunk_list capacity check in sctp_auth_ep_add_chunkid X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=ff04b26794a16a8a879eb4fd2c02c2d6b03850e9;p=thirdparty%2Fkernel%2Flinux.git sctp: fix auth_chunk_list capacity check in sctp_auth_ep_add_chunkid sctp_auth_ep_add_chunkid() uses SCTP_NUM_CHUNK_TYPES (20) as the capacity limit for ep->auth_chunk_list, allowing it to hold up to 20 chunk entries (param_hdr.length up to 24). However, the copy destination asoc->c.auth_chunks in struct sctp_cookie is only SCTP_AUTH_MAX_CHUNKS (16) entries (20 bytes). When more than 16 chunks are added, sctp_association_init() memcpy overflows the destination by up to 4 bytes. Fix by using SCTP_AUTH_MAX_CHUNKS as the capacity limit, matching the destination capacity. Fixes: 1f485649f529 ("[SCTP]: Implement SCTP-AUTH internals") Signed-off-by: HanQuan Acked-by: Xin Long Link: https://patch.msgid.link/20260713032021.3491702-1-zhoujian.zja@antgroup.com Signed-off-by: Jakub Kicinski --- diff --git a/net/sctp/auth.c b/net/sctp/auth.c index be9782760f50..c901d373af80 100644 --- a/net/sctp/auth.c +++ b/net/sctp/auth.c @@ -672,7 +672,7 @@ int sctp_auth_ep_add_chunkid(struct sctp_endpoint *ep, __u8 chunk_id) /* Check if we can add this chunk to the array */ param_len = ntohs(p->param_hdr.length); nchunks = param_len - sizeof(struct sctp_paramhdr); - if (nchunks == SCTP_NUM_CHUNK_TYPES) + if (nchunks == SCTP_AUTH_MAX_CHUNKS) return -EINVAL; p->chunks[nchunks] = chunk_id;