In the Linux kernel, the following vulnerability has been resolved: nfsd: fix use-after-free due to delegation race A delegation break could arrive as soon as we've called vfs_setlease. A delegation break runs a callback which immediately (in nfsd4_cb_recall_prepare) adds the delegation to del_recall_lru. If we then exit nfs4_set_delegation without hashing the delegation, it will be freed as soon as the callback is done with it, without ever being removed from del_recall_lru. Symptoms show up later as use-after-free or list corruption warnings, usually in the laundromat thread. I suspect aba2072f4523 "nfsd: grant read delegations to clients holding writes" made this bug easier to hit, but I looked as far back as v3.0 and it looks to me it already had the same problem. So I'm not sure where the bug was introduced; it may have been there from the beginning.
History

Mon, 04 Nov 2024 12:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-05-24T15:01:52.746Z

Updated: 2024-11-04T12:07:14.801Z

Reserved: 2024-05-22T06:20:56.205Z

Link: CVE-2021-47506

cve-icon Vulnrichment

Updated: 2024-08-04T05:39:59.751Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2024-05-24T15:15:11.197

Modified: 2024-05-24T18:09:20.027

Link: CVE-2021-47506

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-05-24T00:00:00Z

Links: CVE-2021-47506 - Bugzilla