s390/vfio_ccw: Fix out of bounds check on CCW array

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-80550
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-26 15:17:09 UTC
Updated2026-10-16 20:17:59 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: s390/vfio_ccw: Fix out of bounds check on CCW array The routine ccwchain_calc_length() counts the number of channel command words (CCWs) that are chained together in a single channel program, and rejects anything larger than CCWCHAIN_LEN_MAX (256) CCWs. The loop itself is "do..while (count < 257)", and while the logic in is_cpa_within_range() correctly adjusts between the 0-index array of CCWs and the count of CCWs starting at 1, this means it would look at a possible 257th CCW before ending the loop and (correctly) returning an error. Fix this by restructuring the loop to break as soon as 256 CCWs (thus indexes 0-255) are examined, without looking at memory outside the range.

Risk And Classification

Primary CVSS: v3.1 7.9 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:L

EPSS: 0.001810000 probability, percentile 0.072160000 (date 2026-10-16)

VersionSourceTypeScoreSeverityVector
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary7.9HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:L
3.1CNADECLARED7.9HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:L

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
None
Availability
Low

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:L

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 0a19e61e6d4c6192077ead760ba0a2d350987d4c 0282fb1c4b638eecfe2cc558092c460911d8f7e2 git Not specified
CNA Linux Linux affected 0a19e61e6d4c6192077ead760ba0a2d350987d4c 907adc667d902fafbdb2d740d57b55bd025dc4cd git Not specified
CNA Linux Linux affected 0a19e61e6d4c6192077ead760ba0a2d350987d4c f20be33d093ce7630c17ff7ed93caf7eaf8ac1a3 git Not specified
CNA Linux Linux affected 0a19e61e6d4c6192077ead760ba0a2d350987d4c af3f80ca4c8b17f20f9e588def076288fdb49e65 git Not specified
CNA Linux Linux affected 0a19e61e6d4c6192077ead760ba0a2d350987d4c 499a8a66b1598bfab97182aed15e0f1646074a3d git Not specified
CNA Linux Linux affected 0a19e61e6d4c6192077ead760ba0a2d350987d4c 4c2e1d359d7a2b82cdf3254e4e480af9417f99fb git Not specified
CNA Linux Linux affected 0a19e61e6d4c6192077ead760ba0a2d350987d4c d5d096cd9369e986d4e5153baa86b8b35c283e09 git Not specified
CNA Linux Linux affected 0a19e61e6d4c6192077ead760ba0a2d350987d4c a005b7f1a491ffda61bff0fd0f6548f8986fb977 git Not specified
CNA Linux Linux affected 4.12 Not specified
CNA Linux Linux unaffected 4.12 semver Not specified
CNA Linux Linux unaffected 5.10.266 5.10.* semver Not specified
CNA Linux Linux unaffected 5.15.217 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.184 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.153 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.105 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.46 6.18.* semver Not specified
CNA Linux Linux unaffected 7.1.10 7.1.* semver Not specified
CNA Linux Linux unaffected 7.2 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/d5d096cd9369e986d4e5153baa86b8b35c283e09 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/499a8a66b1598bfab97182aed15e0f1646074a3d 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/0282fb1c4b638eecfe2cc558092c460911d8f7e2 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/f20be33d093ce7630c17ff7ed93caf7eaf8ac1a3 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/907adc667d902fafbdb2d740d57b55bd025dc4cd 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/a005b7f1a491ffda61bff0fd0f6548f8986fb977 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/af3f80ca4c8b17f20f9e588def076288fdb49e65 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/4c2e1d359d7a2b82cdf3254e4e480af9417f99fb 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
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