ksmbd: replace hardcoded hdr2_len with offsetof() in smb2_calc_max_out_buf_len()

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2026-31478
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-04-22 14:16:44 UTC
Updated2026-04-27 23:23:52 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: ksmbd: replace hardcoded hdr2_len with offsetof() in smb2_calc_max_out_buf_len() After this commit (e2b76ab8b5c9 "ksmbd: add support for read compound"), response buffer management was changed to use dynamic iov array. In the new design, smb2_calc_max_out_buf_len() expects the second argument (hdr2_len) to be the offset of ->Buffer field in the response structure, not a hardcoded magic number. Fix the remaining call sites to use the correct offsetof() value.

Risk And Classification

Primary CVSS: v3.1 9.8 CRITICAL from 416baaa9-dc9f-4396-8d5f-8c081fb06d67

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

EPSS: 0.000300000 probability, percentile 0.086120000 (date 2026-04-27)

Problem Types: NVD-CWE-noinfo

VersionSourceTypeScoreSeverityVector
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Linux Linux Kernel All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected f2283680a80571ca82d710bc6ecd8f8beac67d63 70b4c414889492c522b6e4331562360f49be2361 git Not specified
CNA Linux Linux affected 9f297df20d93411c0b4ddad7f88ba04a7cd36e77 9a7166f0ef8cbb7bb48dd05e2471d995566003f5 git Not specified
CNA Linux Linux affected e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d c3a89e3ec1ccf64fa6a34e391e1581ebbcba8683 git Not specified
CNA Linux Linux affected e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d 6aef1765d6807e0f027cd87f6ac973eb0879a46d git Not specified
CNA Linux Linux affected e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d 80824c7e527b70cf9039534e60aff592e8f209d1 git Not specified
CNA Linux Linux affected e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d 4cb537ae4f37d7d0f617815ed4bed7173fb50861 git Not specified
CNA Linux Linux affected e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d 0e55f63dd08f09651d39e1b709a91705a8a0ddcb git Not specified
CNA Linux Linux affected 6.6 Not specified
CNA Linux Linux unaffected 6.6 semver Not specified
CNA Linux Linux unaffected 5.15.203 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.168 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.131 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.80 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.21 6.18.* semver Not specified
CNA Linux Linux unaffected 6.19.11 6.19.* semver Not specified
CNA Linux Linux unaffected 7.0 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/6aef1765d6807e0f027cd87f6ac973eb0879a46d 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/0e55f63dd08f09651d39e1b709a91705a8a0ddcb 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/80824c7e527b70cf9039534e60aff592e8f209d1 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/4cb537ae4f37d7d0f617815ed4bed7173fb50861 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/70b4c414889492c522b6e4331562360f49be2361 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/9a7166f0ef8cbb7bb48dd05e2471d995566003f5 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/c3a89e3ec1ccf64fa6a34e391e1581ebbcba8683 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis
© CVE.report 2026 |

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report