Description
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.
References6
- git.kernel.org/stable/c/06f4d6e5a8af6c2072e8cd39dbc512c683ca7fb2
- git.kernel.org/stable/c/15fb4559a7fdf0b8725e433a71cfd03a1313a48b
- git.kernel.org/stable/c/2ce00bb19db13606cda79f4b7aae4d9775de3096
- git.kernel.org/stable/c/4ee94790490ae8dcc97df8597f07836c8a81bbcf
- git.kernel.org/stable/c/5405c90d6a47b3014e74ee0618a162449abbbc93
- git.kernel.org/stable/c/a1625f66eaa1200068a0e2c05bc90e65182fc4e3
Metrics
- CVSS 3.1
-
9.3
CRITICAL
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 4 · as of 9 November 2026
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