From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D5BDE5908C4 for ; Fri, 11 Sep 2026 20:02:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156963; cv=none; b=k5CXa1jvWwEX81DrU5Kg4ddtrbUW6XP+v3VhYdrRzfz0yjGmHScM4nxCRMAfiZ5RhBjYEuoK72ydaHq8WxV0AidZAlq1HmG/y1RDeDkvZRww3oiTDK5DpL+wLxEP6My5m1ZpImUtgMN9j91KWOiSlCXcDLQvkipHrc41Geq/ujc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156963; c=relaxed/simple; bh=LfostAvZwPsw4SIKNyVkCzEg5nQ8z4+/dqOmAUMB6oY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=kOtqpJq/r5KiDYy57Pe1u3uiUhykqSjw9aEER5Maj5jiFiHgKWL0pujT424jB1aw81KdPeESjsgQgPFLHAkIafvHoiMnHpI10LkVDITLbT2Lewzl3z1i6T4gNIgokhTQFraJNlUOmeSZY4OyLfKPDytCNkBLRSwwqCN9QQ/pCf8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=U5gyE1OS; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="U5gyE1OS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3FEDC1F00899; Fri, 11 Sep 2026 20:02:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156945; bh=shl11sjcO8nULG1Bsgt3Lg9wMAOXYT2JlxAgj7JiWHw=; h=From:To:Cc:Subject:Date:Reply-To; b=U5gyE1OSl4615PMAKfdFszy4S8fLGn6VN7VNp0g3pM6PQW4qxeA4SH+ETI5y45V26 CJxbDwZTS20TLg9p2osYt3WwEx3yGyYcG3PIYgqm1smGzz+LUwMZC1O+K6Bq0ZQHJV 1qSq/E9J79xFFKhw/YExF8hLdNtBz/KmKM5ZgysM= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89685: nfsd: fix clock domain mismatch in clients_still_reclaiming() Date: Fri, 11 Sep 2026 21:46:14 +0200 Message-ID: <2026091152-CVE-2026-89685-7511@gregkh> X-Mailer: git-send-email 2.55.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2683; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=v+O/p2oCZMUI+UcUTKOlQ+5/zpjhyWiJVGmPT7lxMRc=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIhtuCuQwcvZJLM/ZE6d329Nk88HPs88UX57jvHrhi /2ewkK/OmJZGASZGGTFFFm+bOM5ur/ikKKXoe1pmDmsTCBDGLg4BWAi7O0Mc7hu/jR78Dn/OK/N bqsTip1Xa5s1PjEsuPaCc/FR033MGfJ1Yb+FjOov9F+4AAA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: nfsd: fix clock domain mismatch in clients_still_reclaiming() clients_still_reclaiming() computes a deadline from nn->boot_time (CLOCK_REALTIME, ~1.7 billion) but compares it against ktime_get_boottime_seconds() (CLOCK_BOOTTIME, seconds since boot). The comparison is always false — it would take ~54 years of uptime for BOOTTIME to exceed the REALTIME-derived deadline. This means any client can hold the server in grace indefinitely by sending CLAIM_PREVIOUS OPEN requests, blocking all non-reclaim operations for all other clients. Add boot_time_bt (CLOCK_BOOTTIME) alongside the existing boot_time and use it for the deadline computation. boot_time (CLOCK_REALTIME) is preserved for its cl_boot clientid-nonce role. The Linux kernel CVE team has assigned CVE-2026-89685 to this issue. Affected and fixed versions =========================== Issue introduced in 5.6 with commit 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf and fixed in 6.18.51 with commit f9cec313efb2fd18d962aad738a4892bce806016 Issue introduced in 5.6 with commit 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf and fixed in 7.2.4 with commit 9843649196221152b6e5d138a3ce859bdaae1d96 Issue introduced in 5.6 with commit 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf and fixed in 7.3-rc1 with commit 09ea3eb9a518565f5bca386e81b993ed8825f5e8 Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2026-89685 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: fs/nfsd/netns.h fs/nfsd/nfs4state.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/f9cec313efb2fd18d962aad738a4892bce806016 https://git.kernel.org/stable/c/9843649196221152b6e5d138a3ce859bdaae1d96 https://git.kernel.org/stable/c/09ea3eb9a518565f5bca386e81b993ed8825f5e8