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 22C38558219 for ; Fri, 11 Sep 2026 20:02:36 +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=1789156971; cv=none; b=REELpCSUPb75a7davR7mkIczl/f1QZGL32MbgbSQrNsFsDPcz9kIwsYGkAekQ7QgW3iBEESwFOiDUXnNjUzpDk6fW57sA6F/7F2JK2U78LIpaMJI4+y/LiR6zCFF6P7zbFSsAIURpuWAKSW9h62nq5PCPMN1wHeKd1QMB9LTUu4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156971; c=relaxed/simple; bh=rdAqyM7URb9zGQ+qw6eVujp5XT3xyOfz1qqsdspfWrc=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=EvB2s08/oDp5gXkQQlmmnQfWSq6IOSwYf6RLVoby/AZVd2HbL4gQMW3Azs/tfrjUb7iMIbRoUfOcRkL/tPG5A1WNT/N14fYER1vS/L3Hx41VyDb5AOukd0LL9TyQil+euGz7vVCNdei1+ZxjsriLBeIC/fNDG/rjvKlABAXlftk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ddss3odI; 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="ddss3odI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5114D1F0089A; Fri, 11 Sep 2026 20:02:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156954; bh=rRD/q8t0jF5iPQ//FonBdu0DQiBrZPINDcceU6TOVvc=; h=From:To:Cc:Subject:Date:Reply-To; b=ddss3odIVSRQbF5p/2X4aT6gxI3eLs8wyPTIZYUWoao0R1eG9aAh5Hym2DMg5kof6 0sAnVrAPABiiLAW3UsrKUd6rMBLKjdmbBqfdUzu53LSaNYBSfLaqcwsIaJgZ7fN9ml gU2kNC6sRaZWqL2cOE2JRhMfzIaSE1Ow6BczQONM= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89688: nfsd: drop the stateid, not the stateowner, on seqid_op replay retry Date: Fri, 11 Sep 2026 21:46:17 +0200 Message-ID: <2026091152-CVE-2026-89688-696b@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=3292; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=bxTvkFaxGQ4uKppmJL5SS4BF3FJZlzM/ApnLheJQCU8=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIhsO57rdio27M+f3otbVpY8EYt3rJxT47XpnuUgq6 1Zb1Re9jlgWBkEmBlkxRZYv23iO7q84pOhlaHsaZg4rE8gQBi5OAZjI3BKG+TEb2zcXzYg6mSIe wfcuztE8h2e3PMM8C0u9rLcGS99Jh7nGrz2aH9KmNqMAAA== 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: drop the stateid, not the stateowner, on seqid_op replay retry In nfs4_preprocess_seqid_op() the stateid is obtained from nfsd4_lookup_stateid(), which holds a reference on the nfs4_stid (sc_count) but takes no reference on the stateowner. openlockstateid() merely casts that stid and likewise takes no reference. When nfsd4_cstate_assign_replay() returns -EAGAIN (the replay owner is being torn down, RP_UNHASHED) it has not taken a stateowner reference on that path. The error handling nevertheless called nfs4_put_stateowner(stp->st_stateowner), dropping an so_count reference the function never acquired -- risking a stateowner refcount underflow and use-after-free -- while leaking the sc_count reference held on the stid. The leaked stid reference can also stall a concurrent nfsd4_close_open_stateid() waiting for sc_count to drop. Drop the reference actually held -- the stid -- before retrying. The stateowner stays alive through the reference held by the stid. This mirrors the open path in nfsd4_process_open1(), where the put balances a reference that path explicitly holds on the stateowner. The Linux kernel CVE team has assigned CVE-2026-89688 to this issue. Affected and fixed versions =========================== Issue introduced in 6.10 with commit eec7620800081e27dbf8019ac2e66259f0d5bf6f and fixed in 6.12.109 with commit 69ed78b6b947c9257213164678b4edf17533093b Issue introduced in 6.10 with commit eec7620800081e27dbf8019ac2e66259f0d5bf6f and fixed in 6.18.50 with commit 00843074d9b84824552c9679d423d29500ca5de0 Issue introduced in 6.10 with commit eec7620800081e27dbf8019ac2e66259f0d5bf6f and fixed in 7.2.4 with commit f7cb90ddc021747fc9abfd4cf5252d425fd34eec Issue introduced in 6.10 with commit eec7620800081e27dbf8019ac2e66259f0d5bf6f and fixed in 7.3-rc1 with commit 5e4627d3513e60accfce9d5f4c7fa95251ef93d6 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-2026-89688 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/69ed78b6b947c9257213164678b4edf17533093b https://git.kernel.org/stable/c/00843074d9b84824552c9679d423d29500ca5de0 https://git.kernel.org/stable/c/f7cb90ddc021747fc9abfd4cf5252d425fd34eec https://git.kernel.org/stable/c/5e4627d3513e60accfce9d5f4c7fa95251ef93d6