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CVE PROGRAM SOURCE RECORD9.1 Critical

CVE-2026-89671

nfsd: gate nfs3 setacl by argp->mask

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Status
Published
Published
Updated
Assigning organization
Linux

Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: gate nfs3 setacl by argp->mask nfsd3_proc_setacl() calls set_posix_acl() unconditionally for both ACL_TYPE_ACCESS and ACL_TYPE_DEFAULT, passing argp->acl_access and argp->acl_default verbatim. The NFSv3 ACL decoder only populates those pointers when the corresponding mask bit is set: nfs3svc_decode_setaclargs() if (args->mask & NFS_ACL) decode into acl_access if (args->mask & NFS_DFACL) decode into acl_default /* otherwise the pointer stays NULL (pc_argzero) */ nfsd3_proc_setacl() set_posix_acl(.., ACL_TYPE_ACCESS, argp->acl_access) set_posix_acl(.., ACL_TYPE_DEFAULT, argp->acl_default) set_posix_acl(idmap, dentry, type, NULL) is the VFS "remove this ACL type" operation. A NULL pointer that means "the client did not send this arm" is therefore indistinguishable from "the client asked to remove this ACL". A SETACL with mask=NFS_ACL silently drops the directory's default ACL; mask=0 drops both. The sibling nfsd3_proc_getacl() already consults argp->mask before touching each arm; mirror that in setacl. Fix by wrapping each set_posix_acl() call in the matching mask bit check and initializing error to 0 before inode_lock so that a request with neither bit set leaves the on-disk ACLs untouched and returns nfs_ok. The out_drop_lock path and the unconditional posix_acl_release() at out: are preserved; both NULL-tolerate the skipped arms.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • a257cdd0e2179630d3201c32ba14d7fcb3c3a055 to < beeb33152873ad40692bd255b562966f8ba43dbdaffected
  • a257cdd0e2179630d3201c32ba14d7fcb3c3a055 to < 3be1d8611dae4829e4608007db29f4a8748c37b2affected
  • a257cdd0e2179630d3201c32ba14d7fcb3c3a055 to < 68a80b26efdff1d09f8ae1773c6a915abb9e191daffected
  • a257cdd0e2179630d3201c32ba14d7fcb3c3a055 to < b3bff820d068ea59767d4e91a3258231a879da5faffected
  • a257cdd0e2179630d3201c32ba14d7fcb3c3a055 to < ff99ed007f065198fd723152405c22aa558f700baffected
  • a257cdd0e2179630d3201c32ba14d7fcb3c3a055 to < 453d7198a0ab07a12d46e0575861ac7b932da17eaffected

Linux Linux

Default version status: affected

  • 2.6.13affected
  • 0 to < 2.6.13unaffected
  • 6.1.191 to ≤ 6.1.*unaffected
  • 6.6.157 to ≤ 6.6.*unaffected
  • 6.12.109 to ≤ 6.12.*unaffected
  • 6.18.50 to ≤ 6.18.*unaffected
  • 7.2.4 to ≤ 7.2.*unaffected
  • 7.3 to ≤ *unaffected

References