Integer Overflow or Wraparound Affecting openshift/ose-rhel-coreos-9 package, versions *
Threat Intelligence
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Test your applications- Snyk IDSNYK-RHEL8-OPENSHIFTOSERHELCOREOS9-22343992
- published8 Nov 2026
- disclosed28 Oct 2026
Introduced: 28 Oct 2026
NewCVE-2026-99191 (opens in a new tab)How to fix?
There is no fixed version for RHEL:8 openshift/ose-rhel-coreos-9.
NVD Description
Note: Versions mentioned in the description apply only to the upstream openshift/ose-rhel-coreos-9 package and not the openshift/ose-rhel-coreos-9 package as distributed by RHEL.
See How to fix? for RHEL:8 relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
calipso: keep BIG TCP payload_len in calipso_skbuff_setattr()
calipso_skbuff_setattr() adjusts payload_len by the length of the option it inserts or resizes:
payload = ntohs(ip6_hdr->payload_len);
ip6_hdr->payload_len = htons(payload + len_delta);
GRO can build BIG TCP packets larger than IPV6_MAXPLEN, and stores payload_len == 0 for them; ipv6_payload_len() then falls back to skb->len. For such a packet forwarded to a destination mapped to CALIPSO, the code above writes len_delta (or 65536 + len_delta when shrinking) into payload_len, and ipv6_payload_len() no longer falls back to skb->len. nf_tables, conntrack and sch_cake rely on it.
The same arithmetic also wraps when a packet grows past IPV6_MAXPLEN, and a BIG TCP packet that shrinks below IPV6_MAXPLEN should get its real length back.
Set payload_len from the skb length with ipv6_set_payload_len(), which stores 0 above IPV6_MAXPLEN and the real length otherwise, as ipv6_gro_complete() does. The network header was just reset to skb->data, so skb->len - sizeof(*ip6_hdr) is the payload length.
Tested on one kernel (arm64, QEMU) with SELinux permissive, a minimal mdp-generated policy (network_peer_controls=1), "netlabelctl calipso add pass doi:16" and a NetLabel mapping of fd00:2::/64 to CALIPSO DOI 16. calipso_skbuff_setattr() was called through netlbl_skbuff_setattr() from a test-only debugfs hook (not part of this patch) adding a level-only label; payload_len after the call:
case before fix after fix real length 1000, unlabeled 1016 1016 1016 70000 GSO, payload_len 0 16 0 70016 65530 GSO, grows past MAXPLEN 10 0 65546 65540 GSO with a 24 byte hop header, shrinks below MAXPLEN 65528 65532 65532 1000 with a 24 byte hop header 992 992 992
(0 means ipv6_payload_len() returns the real length.) On the forward path, with a client injecting unlabeled UDP through a router to a server, the router adds the CALIPSO option and the server delivers all datagrams (Udp6InDatagrams 5, Ip6InTruncatedPkts 0) with this patch.
References
- https://access.redhat.com/security/cve/CVE-2026-99191
- https://git.kernel.org/stable/c/1c9fcfca51e3c5cd46dd72a4da74d56eff183513
- https://git.kernel.org/stable/c/8070ed578b6b9134e045627fb745c887a806d46e
- https://git.kernel.org/stable/c/8ee0e03663826a76507048d58466b29321a57656
- https://git.kernel.org/stable/c/929dc8e2c9165bb651dca26b2c68067a3880406b
- https://git.kernel.org/stable/c/e29d0a00c619ac794b05d64f4438204478137365