From: Xin Long <lucien.xin@gmail.com> stable inclusion from stable-v6.18.36 commit 7560afb8cddafd829e709d7ea09230e45a825557 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/15910 CVE: CVE-2026-53224 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 6f4c80a2a7e6d06753b89a578b710a2499a5e62b ] 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. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Sashiko <sashiko-bot@kernel.org> Signed-off-by: Xin Long <lucien.xin@gmail.com> Link: https://patch.msgid.link/75af23a89adf881a0895d511775e4770da367cbf.1780873427... Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Conflicts: net/sctp/sm_make_chunk.c [Just context conflicts.] Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com> --- net/sctp/bind_addr.c | 11 ++++++++++- net/sctp/sm_make_chunk.c | 9 +++++++-- 2 files changed, 17 insertions(+), 3 deletions(-) diff --git a/net/sctp/bind_addr.c b/net/sctp/bind_addr.c index 6b95d3ba8fe1..0947b276d1e0 100644 --- a/net/sctp/bind_addr.c +++ b/net/sctp/bind_addr.c @@ -273,10 +273,20 @@ int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list, /* Convert the raw address to standard address format */ while (addrs_len) { param = (struct sctp_paramhdr *)raw_addr_list; rawaddr = (union sctp_addr_param *)raw_addr_list; + if (addrs_len < sizeof(*param)) { + retval = -EINVAL; + goto out_err; + } + len = ntohs(param->length); + if (addrs_len < len) { + retval = -EINVAL; + goto out_err; + } + af = sctp_get_af_specific(param_type2af(param->type)); if (unlikely(!af) || !af->from_addr_param(&addr, rawaddr, htons(port), 0)) { retval = -EINVAL; goto out_err; @@ -289,11 +299,10 @@ int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list, if (retval) /* Can't finish building the list, clean up. */ goto out_err; next: - len = ntohs(param->length); addrs_len -= len; raw_addr_list += len; } return retval; diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 2f910e6b00d4..7269a8e8e54b 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -1748,13 +1748,13 @@ struct sctp_association *sctp_unpack_cookie( int headersize, bodysize, fixed_size; struct sctp_signed_cookie *cookie; struct sk_buff *skb = chunk->skb; struct sctp_cookie *bear_cookie; struct sctp_chunkhdr *ch; + unsigned int len, chlen; __u8 *digest = ep->digest; enum sctp_scope scope; - unsigned int len; ktime_t kt; /* Header size is static data prior to the actual cookie, including * any padding. */ @@ -1779,11 +1779,16 @@ struct sctp_association *sctp_unpack_cookie( /* Process the cookie. */ cookie = chunk->subh.cookie_hdr; bear_cookie = &cookie->c; ch = (struct sctp_chunkhdr *)(bear_cookie + 1); - if (ntohs(ch->length) > len - fixed_size) + chlen = ntohs(ch->length); + if (chlen < sizeof(struct sctp_init_chunk)) + goto malformed; + if (chlen > len - fixed_size) + goto malformed; + if (bear_cookie->raw_addr_list_len > len - fixed_size - chlen) goto malformed; if (!sctp_sk(ep->base.sk)->hmac) goto no_hmac; -- 2.43.0