Paper/Archive/CVE-2026-90037

CVE-2026-90037

Linux Linux — NFSD: Prevent client use-after-free during close_lru reaping

Description · from the CVE record

In the Linux kernel, the following vulnerability has been resolved: NFSD: Prevent client use-after-free during close_lru reaping An nfs4_openowner left on nn->close_lru after its final CLOSE keeps its last closed stateid in oo_last_closed_stid, holding only a raw pointer to its nfs4_client. The laundromat reaps timed-out entries, drops nn->client_lock, and calls nfs4_put_stid(), which dereferences the client through cl_lock. Nothing pins the client across that window, so a concurrent force_expire_client() can free it and nfs4_put_stid() reads freed memory. __destroy_client() hits the same race, walking clp->cl_openowners without cl_lock. Pin the client with cl_rpc_users before dropping client_lock, and skip clients already expiring. __destroy_client() then cleans up its own close_lru entries through release_last_closed_stateid(), so teardown no longer races the laundromat.

Affected

ProductAffectedFixed inSource
Linux217526e7ecc9f6f243e976772e81eab7ab986a4c – < adc34b5df5c5d87043cb500b0867fc1c4ad0117eadc34b5df5c5d87043cb500b0867fc1c4ad0117eCNA
Linux217526e7ecc9f6f243e976772e81eab7ab986a4c – < 0763482227822f7343557f086afc382086d56c4c0763482227822f7343557f086afc382086d56c4cCNA
Linux217526e7ecc9f6f243e976772e81eab7ab986a4c – < 83dd59ac1c3455c2c7d8ddb582d980a13199b9b383dd59ac1c3455c2c7d8ddb582d980a13199b9b3CNA
Linux217526e7ecc9f6f243e976772e81eab7ab986a4c – < e57a9ed34ea8c17e831de59b8f1a6b2d80d347a1e57a9ed34ea8c17e831de59b8f1a6b2d80d347a1CNA
Linux217526e7ecc9f6f243e976772e81eab7ab986a4c – < 2330b788d732f43668b965b3105b37ceb276dfea2330b788d732f43668b965b3105b37ceb276dfeaCNA
Linux3.17–CNA

Scores by source

Linux (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

refgit.kernel.org/stable/c/adc34b5df5c5d87043cb500b0867fc1c4ad0117erefgit.kernel.org/stable/c/0763482227822f7343557f086afc382086d56c4crefgit.kernel.org/stable/c/83dd59ac1c3455c2c7d8ddb582d980a13199b9b3refgit.kernel.org/stable/c/e57a9ed34ea8c17e831de59b8f1a6b2d80d347a1refgit.kernel.org/stable/c/2330b788d732f43668b965b3105b37ceb276dfea