by Kastro
Paper/Archive/CVE-2026-80554

CVE-2026-80554

Linux Linux — s390/vfio_ccw: Limit the number of channel program segments

EPSS 0.2%CVSS 9.3
critical.is priorityof 100
30
CVSS 9.3 (CNA)9.3 / 10 × 3027.9Not in CISA KEV+300.0EPSS percentile 9.3.093 × 201.9No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

In the Linux kernel, the following vulnerability has been resolved: s390/vfio_ccw: Limit the number of channel program segments The processing of channel programs, and the CCWs within them, is done recursively. As such, there is an arbitrary (but not architectural) limit to the number of CCWs that can exist in a single channel program. The vfio-ccw logic breaks these channel programs into segments whenever it encounters a Transfer-In-Channel (TIC) CCW, and the combined number of segments count towards the global limit. Impose an equivalent limit to the number of segments until such logic can be made non-recursive.

Affected

ProductAffectedFixed inSource
Linux0a19e61e6d4c6192077ead760ba0a2d350987d4c – < 15fb4559a7fdf0b8725e433a71cfd03a1313a48b15fb4559a7fdf0b8725e433a71cfd03a1313a48bCNA
Linux0a19e61e6d4c6192077ead760ba0a2d350987d4c – < a1625f66eaa1200068a0e2c05bc90e65182fc4e3a1625f66eaa1200068a0e2c05bc90e65182fc4e3CNA
Linux0a19e61e6d4c6192077ead760ba0a2d350987d4c – < 06f4d6e5a8af6c2072e8cd39dbc512c683ca7fb206f4d6e5a8af6c2072e8cd39dbc512c683ca7fb2CNA
Linux0a19e61e6d4c6192077ead760ba0a2d350987d4c – < 4ee94790490ae8dcc97df8597f07836c8a81bbcf4ee94790490ae8dcc97df8597f07836c8a81bbcfCNA
Linux0a19e61e6d4c6192077ead760ba0a2d350987d4c – < 5405c90d6a47b3014e74ee0618a162449abbbc935405c90d6a47b3014e74ee0618a162449abbbc93CNA
Linux4.12–CNA

Scores by source

Linux (CNA)9.3CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

refgit.kernel.org/stable/c/15fb4559a7fdf0b8725e433a71cfd03a1313a48brefgit.kernel.org/stable/c/a1625f66eaa1200068a0e2c05bc90e65182fc4e3refgit.kernel.org/stable/c/06f4d6e5a8af6c2072e8cd39dbc512c683ca7fb2refgit.kernel.org/stable/c/4ee94790490ae8dcc97df8597f07836c8a81bbcfrefgit.kernel.org/stable/c/5405c90d6a47b3014e74ee0618a162449abbbc93