{"id":"CVE-2026-22980","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: provide locking for v4_end_grace\n\nWriting to v4_end_grace can race with server shutdown and result in\nmemory being accessed after it was freed - reclaim_str_hasht…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: provide locking for v4_end_grace\n\nWriting to v4_end_grace can race with server shutdown and result in\nmemory being accessed after it was freed - reclaim_str_hasht…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-416"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 3.18, < 5.10.248","linux_kernel >= 5.11, < 5.15.198","linux_kernel >= 5.16, < 6.1.161","linux_kernel >= 6.2, < 6.6.121","linux_kernel >= 6.7, < 6.12.66","linux_kernel >= 6.13, < 6.18.6","linux_kernel = 6.19"],"patched":["linux_kernel 6.18.6"],"published":"2026-01-23","updated":"2026-10-15","sourceUpdated":"2026-10-15T02:18:38.463","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-22980","references":[{"url":"https://git.kernel.org/stable/c/06600719d0f7a723811c45e4d51f5b742f345309","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2857bd59feb63fcf40fe4baf55401baea6b4feb4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/34eb22836e0cdba093baac66599d68c4cd245a9d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/53f07d095e7e680c5e4569a55a019f2c0348cdc6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ba4811c8b433bfa681729ca42cc62b6034f223b0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ca97360860eb02e3ae4ba42c19b439a0fcecbf06","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e8bfa2401d4c51eca6e48e9b33c798828ca9df61","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-457936.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00147,"epssPercentile":0.0391,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-06-16T20:36:55.336499Z"},"ingestedAt":"2026-09-08T15:33:26.994Z","slug":"CVE-2026-22980","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: provide locking for v4_end_grace\n\nWriting to v4_end_grace can race with server shutdown and result in\nmemory being accessed after it was freed - reclaim_str_hashtbl in\nparticularly.\n\nWe cannot hold nfsd_mutex across the nfsd4_end_grace() call as that is\nheld while client_tracking_op->init() is called and that can wait for\nan upcall to nfsdcltrack which can write to v4_end_grace, resulting in a\ndeadlock.\n\nnfsd4_end_grace() is also called by the landromat work queue and this\ndoesn't require locking as server shutdown will stop the work and wait\nfor it before freeing anything that nfsd4_end_grace() might access.\n\nHowever, we must be sure that writing to v4_end_grace doesn't restart\nthe work item after shutdown has already waited for it.  For this we\nadd a new flag protected with nn->client_lock.  It is set only while it\nis safe to make client tracking calls, and v4_end_grace only schedules\nwork while the flag is set with the spinlock held.\n\nSo this patch adds a nfsd_net field \"client_tracking_active\" which is\nset as described.  Another field \"grace_end_forced\", is set when\nv4_end_grace is written.  After this is set, and providing\nclient_tracking_active is set, the laundromat is scheduled.\nThis \"grace_end_forced\" field bypasses other checks for whether the\ngrace period has finished.\n\nThis resolves a race which can result in use-after-free.\n\n## Affected\n\n- `linux_kernel >= 3.18, < 5.10.248`\n- `linux_kernel >= 5.11, < 5.15.198`\n- `linux_kernel >= 5.16, < 6.1.161`\n- `linux_kernel >= 6.2, < 6.6.121`\n- `linux_kernel >= 6.7, < 6.12.66`\n- `linux_kernel >= 6.13, < 6.18.6`\n- `linux_kernel = 6.19`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.18.6`","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}