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 AC68858FD1E for ; Fri, 11 Sep 2026 20:02:53 +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=1789156993; cv=none; b=mkSxrUNprbs/CcatdHcfLCZQnk0rB7b35rRllAupVFROD1KrK/enp2oZDv0WJ2u+pI8fKVIIwxVp74bql2Tqrgscc4taYjt4OZ4xU+8xtSN9Z+XFob+hUauK6bUv5brDHuVKH2D5JZc6xtoi4gD/l4WH0qCAY7BaorutOX/Yxi4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156993; c=relaxed/simple; bh=A5DhkgYpZXqoAS6k48qIAlWwWGS+jsNvMFB6HSyRkoY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=YwMAYIxc7wTO5uvaOlIe30U0vQ/ALduJOTgvtvZhqcyv8c3DWGdp+QN3ccNi+Sr/pB4/SHvGSlIBWlIV+nRXJCpGauEkFt10tETu3ZuvmeXmrlxLBEtS/Ogqp9owCrwTeA8Z9AQFT4w8S/HJW/RJHqr8MCtX0mBRyXnBPWQX5xI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=QHjNgHpG; 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="QHjNgHpG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 72DAA1F000FF; Fri, 11 Sep 2026 20:02:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156970; bh=ipncCxLJDlHmhiIouooJjV6eW2Q7G/3ouSNLJvc2wTQ=; h=From:To:Cc:Subject:Date:Reply-To; b=QHjNgHpGDAimMrvicfTrc2hB6rSITnvbqlqFWeDbYdnczdD5y7Xj1X0+oMcB+2lUg U0X8l+5R7XSYAj6P1vQtkdS2N1kaYvBT7S4h6QZrWo7vcOf0KFi5nPd54cohzPCkqu 6ztfK/bOiy2ur6JgLZrQGvVnVtvQQKapXXvtkIA8= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89692: nfsd: clear CALLBACK_RUNNING on failed delegation recall queue Date: Fri, 11 Sep 2026 21:46:21 +0200 Message-ID: <2026091153-CVE-2026-89692-508f@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=2788; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=Sa9WN/Gnw5AyCDAm1xm/2W8zl60tbJj+renlLrl7QQc=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIhunaSXPVW6t+9LPKZlsenrGlWKWD9N+/z4QqCS8b I9AumtpRywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAEzkXQzD/ISVzA+EDA4seLKQ awV/9ZdLYRvEJjIsuPH6pu0HK73lHmndRdM+5i9n0okQAAA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: nfsd: clear CALLBACK_RUNNING on failed delegation recall queue nfsd_break_one_deleg() sets NFSD4_CALLBACK_RUNNING via test_and_set_bit at entry to serialize recall work, then calls nfsd4_run_cb() to queue the recall. When the queue attempt fails the refcount bump is undone, but the RUNNING bit is left set. The only site that clears the bit is nfsd41_destroy_cb() (fs/nfsd/nfs4callback.c), which runs from the workqueue and is therefore unreachable when nothing was queued. The bit becomes a permanent latch on dp->dl_recall.cb_flags: every subsequent break_lease() on the same delegation hits the early-return guard in nfsd_break_one_deleg() and silently skips the recall, so the delegation is never broken and the conflicting open or lock stalls. Fix by clearing NFSD4_CALLBACK_RUNNING on the !queued branch alongside the refcount_dec. The Linux kernel CVE team has assigned CVE-2026-89692 to this issue. Affected and fixed versions =========================== Issue introduced in 6.15 with commit 1054e8ffc5c492f341bdf1888b882f1d163dd3d8 and fixed in 6.18.50 with commit b137930ee52e3ef38915a3511d4c070463b63a32 Issue introduced in 6.15 with commit 1054e8ffc5c492f341bdf1888b882f1d163dd3d8 and fixed in 7.2.4 with commit cb2d0c4d1b3d301d042ed61365eaa8cb0141a254 Issue introduced in 6.15 with commit 1054e8ffc5c492f341bdf1888b882f1d163dd3d8 and fixed in 7.3-rc1 with commit b036727d334b1b7cd4c1f1fba3b59ba93a6bbe96 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-2026-89692 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/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/b137930ee52e3ef38915a3511d4c070463b63a32 https://git.kernel.org/stable/c/cb2d0c4d1b3d301d042ed61365eaa8cb0141a254 https://git.kernel.org/stable/c/b036727d334b1b7cd4c1f1fba3b59ba93a6bbe96