{"id":"DEBIAN-CVE-2026-22980","details":"In the Linux kernel, the following vulnerability has been resolved:  nfsd: provide locking for v4_end_grace  Writing to v4_end_grace can race with server shutdown and result in memory being accessed after it was freed - reclaim_str_hashtbl in particularly.  We cannot hold nfsd_mutex across the nfsd4_end_grace() call as that is held while client_tracking_op-\u003einit() is called and that can wait for an upcall to nfsdcltrack which can write to v4_end_grace, resulting in a deadlock.  nfsd4_end_grace() is also called by the landromat work queue and this doesn't require locking as server shutdown will stop the work and wait for it before freeing anything that nfsd4_end_grace() might access.  However, we must be sure that writing to v4_end_grace doesn't restart the work item after shutdown has already waited for it.  For this we add a new flag protected with nn-\u003eclient_lock.  It is set only while it is safe to make client tracking calls, and v4_end_grace only schedules work while the flag is set with the spinlock held.  So this patch adds a nfsd_net field \"client_tracking_active\" which is set as described.  Another field \"grace_end_forced\", is set when v4_end_grace is written.  After this is set, and providing client_tracking_active is set, the laundromat is scheduled. This \"grace_end_forced\" field bypasses other checks for whether the grace period has finished.  This resolves a race which can result in use-after-free.","modified":"2026-02-27T17:24:34.730863Z","published":"2026-01-23T16:15:54.003Z","upstream":["CVE-2026-22980"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-22980"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:11","purl":"pkg:deb/debian/linux?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.10.249-1"}]}],"versions":["5.10.103-1","5.10.103-1~bpo10+1","5.10.106-1","5.10.113-1","5.10.120-1","5.10.120-1~bpo10+1","5.10.127-1","5.10.127-2","5.10.127-2~bpo10+1","5.10.136-1","5.10.140-1","5.10.148-1","5.10.149-1","5.10.149-2","5.10.158-1","5.10.158-2","5.10.162-1","5.10.178-1","5.10.178-2","5.10.178-3","5.10.179-1","5.10.179-2","5.10.179-3","5.10.179-4","5.10.179-5","5.10.191-1","5.10.197-1","5.10.205-1","5.10.205-2","5.10.209-1","5.10.209-2","5.10.216-1","5.10.218-1","5.10.221-1","5.10.223-1","5.10.226-1","5.10.234-1","5.10.237-1","5.10.244-1","5.10.247-1","5.10.46-4","5.10.46-5","5.10.70-1","5.10.70-1~bpo10+1","5.10.84-1","5.10.92-1","5.10.92-1~bpo10+1","5.10.92-2"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-22980.json"}},{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.162-1"}]}],"versions":["6.1.106-1","6.1.106-2","6.1.106-3","6.1.112-1","6.1.115-1","6.1.119-1","6.1.123-1","6.1.124-1","6.1.128-1","6.1.129-1","6.1.133-1","6.1.135-1","6.1.137-1","6.1.139-1","6.1.140-1","6.1.147-1","6.1.148-1","6.1.153-1","6.1.158-1","6.1.159-1","6.1.27-1","6.1.37-1","6.1.38-1","6.1.38-2","6.1.38-2~bpo11+1","6.1.38-3","6.1.38-4","6.1.38-4~bpo11+1","6.1.52-1","6.1.55-1","6.1.55-1~bpo11+1","6.1.64-1","6.1.66-1","6.1.67-1","6.1.69-1","6.1.69-1~bpo11+1","6.1.76-1","6.1.76-1~bpo11+1","6.1.82-1","6.1.85-1","6.1.90-1","6.1.90-1~bpo11+1","6.1.94-1","6.1.94-1~bpo11+1","6.1.98-1","6.1.99-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-22980.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.12.69-1"}]}],"versions":["6.12.38-1","6.12.41-1","6.12.43-1","6.12.43-1~bpo12+1","6.12.48-1","6.12.57-1","6.12.57-1~bpo12+1","6.12.63-1","6.12.63-1~bpo12+1","6.12.69-1~bpo12+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-22980.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.18.8-1"}]}],"versions":["6.12.38-1","6.12.41-1","6.12.43-1","6.12.43-1~bpo12+1","6.12.48-1","6.12.57-1","6.12.57-1~bpo12+1","6.12.63-1","6.12.63-1~bpo12+1","6.12.69-1","6.12.69-1~bpo12+1","6.12.73-1","6.12.73-1~bpo12+1","6.13.10-1~exp1","6.13.11-1~exp1","6.13.2-1~exp1","6.13.3-1~exp1","6.13.4-1~exp1","6.13.5-1~exp1","6.13.6-1~exp1","6.13.7-1~exp1","6.13.8-1~exp1","6.13.9-1~exp1","6.13~rc6-1~exp1","6.13~rc7-1~exp1","6.14.3-1~exp1","6.14.5-1~exp1","6.14.6-1~exp1","6.15-1~exp1","6.15.1-1~exp1","6.15.2-1~exp1","6.15.3-1~exp1","6.15.4-1~exp1","6.15.5-1~exp1","6.15.6-1~exp1","6.15~rc7-1~exp1","6.16-1~exp1","6.16.1-1~exp1","6.16.10-1","6.16.11-1","6.16.12-1","6.16.12-1~bpo13+1","6.16.12-2","6.16.3-1","6.16.3-1~bpo13+1","6.16.5-1","6.16.6-1","6.16.7-1","6.16.8-1","6.16.9-1","6.16~rc7-1~exp1","6.17.10-1","6.17.11-1","6.17.12-1","6.17.13-1","6.17.13-1~bpo13+1","6.17.2-1~exp1","6.17.5-1~exp1","6.17.6-1","6.17.7-1","6.17.7-2","6.17.8-1","6.17.8-1~bpo13+1","6.17.9-1","6.18.1-1~exp1","6.18.2-1~exp1","6.18.3-1","6.18.5-1","6.18.5-1~bpo13+1","6.18~rc4-1~exp1","6.18~rc4-1~exp2","6.18~rc5-1~exp1","6.18~rc6-1~exp1","6.18~rc7-1~exp1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-22980.json"}},{"package":{"name":"linux-6.1","ecosystem":"Debian:11","purl":"pkg:deb/debian/linux-6.1?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.162-1~deb11u1"}]}],"versions":["6.1.106-3~deb11u1","6.1.106-3~deb11u2","6.1.106-3~deb11u3","6.1.112-1~deb11u1","6.1.119-1~deb11u1","6.1.128-1~deb11u1","6.1.129-1~deb11u1","6.1.137-1~deb11u1","6.1.140-1~deb11u1","6.1.147-1~deb11u1","6.1.148-1~deb11u1","6.1.153-1~deb11u1","6.1.158-1~deb11u1","6.1.159-1~deb11u1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-22980.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}