Evaluate access rules for groups in the access token and honor deny e… - #18381
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…ntries determining permissions. Access rules were previously only matched against the SID of the current user, denying access for files granted through group membership only. Deny entries are now subtracted from allowed rights prior to mapping to permission actions. Fix #18380
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Pull request overview
This PR updates the Windows local permission preflight logic to correctly derive effective read/write/execute actions from NTFS ACLs when access is granted via group membership and when Deny ACEs are present, addressing the incorrect Access denied failures described in #18380.
Changes:
- Match ACL entries against both the current user SID and all group SIDs in the current access token.
- Track accumulated
AllowandDenyrights and compute effective rights by subtracting denied from allowed prior to mapping toPermission.Action. - Preserve the existing read-only attribute behavior by removing write from the resulting action set.
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ylangisc
enabled auto-merge
August 20, 2026 19:14
dkocher
approved these changes
Aug 21, 2026
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…ntries determining permissions.
Access rules were previously only matched against the SID of the current user, denying access for files granted through group membership only. Deny entries are now subtracted from allowed rights prior to mapping to permission actions.
Fix #18380