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 5EC0558FD0C for ; Fri, 11 Sep 2026 20:02:44 +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=1789156977; cv=none; b=jGnxml8ZMS4KcrFtl4GiPhN8IkT/8/HowteiopJybdAcUK/6d7HWVSHz1Hq7+NmktODGaWtaGEgJZW+/AfjVDMYwdh57fzBipxV9Z90L5BdeDsCHcPFcL4CMeWmxtVqUf9srVW5PThaUmWTlRdPy2uWXGl1r7R8izxQ6+kuLwRI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156977; c=relaxed/simple; bh=nQzWwVHSA1SOicC8jJ8Ew8ktoOuOZWPIrpHr1HPX0Ag=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=HVCGrdzDpOJQXqwXLsEPhShIGCHWEySc6eQenxtaTew9sSSjbR1bZXC9q4e2qG7WQhEzRG00ov838XzDcFCUEw17oBP7QPthyUNeRcBF23S92gfHS9Oo1hHBslUtiMCfj+YZZMDm0kl6TVzVM7qUzaAYJjZ03UFT5woTjJsCckk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vaBX3teZ; 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="vaBX3teZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 425D21F00899; Fri, 11 Sep 2026 20:02:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156963; bh=V1faAXpw3G5nguXAuAKYojyeFvpQESuI+uUF3y6qmbE=; h=From:To:Cc:Subject:Date:Reply-To; b=vaBX3teZZ3wGBv+4i4N6hs8TjZX4FHNjAHu2e/VwLJsjUvhZUyVPY1uK+gGqyGDkT NswuEck0kLi6EaFFl7AvN/p7C2JgSYt9XKidHl/eDJr4EtAzPUISLoSZbeBzyKp+PA QgEHCRoroK1IaemXY2Bpf6cTdpVaZxWXWUQMoPGU= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89691: nfsd: clear opcnt on compound arg release to prevent OOB read Date: Fri, 11 Sep 2026 21:46:20 +0200 Message-ID: <2026091153-CVE-2026-89691-6771@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=3041; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=+3pDkfJJxfj/1Kix1FitRvYzJ2mA8tb+yGEmIjU0ioQ=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIhuj2owc5Iq8L4hMV0sQ+/TBkvWet6b0+vTtGtlnl zWuOXewI5aFQZCJQVZMkeXLNp6j+ysOKXoZ2p6GmcPKBDKEgYtTACZyIZVhnsWSbK9Qbp2HIre9 llltnjPj1IqoHQwLZnAt9Hj3tON/ZWF9ZX/ve0a915+EAQ== 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 opcnt on compound arg release to prevent OOB read nfsd4_release_compoundargs() resets args->ops to the inline iops[8] array when the dynamically-allocated ops buffer is freed, but leaves args->opcnt at its original value (which can be up to 200 for NFSv4.1+ compounds). If rq_status_counter is stuck at an odd value (which can happen when nfsd_dispatch() hits an error path after setting it odd), the RPC status dumpit handler reads min(opcnt, 16) entries from args->ops[]. Since iops only has 8 elements and is the last field in struct nfsd4_compoundargs, reading indices 8-15 accesses adjacent slab memory and leaks it to userspace via netlink. Zero opcnt unconditionally in nfsd4_release_compoundargs() so stale compound metadata is never exposed through the status interface. [ cel: Remove the kvfree_rcu_mightsleep() sleep from the exposure window ] The Linux kernel CVE team has assigned CVE-2026-89691 to this issue. Affected and fixed versions =========================== Issue introduced in 6.7 with commit bd9d6a3efa9709e653aafbeb859289feccb8e70c and fixed in 6.12.109 with commit 58bcdfb2b2e412088839ae740b1a95154dc0b8d0 Issue introduced in 6.7 with commit bd9d6a3efa9709e653aafbeb859289feccb8e70c and fixed in 6.18.50 with commit e879148867bd4c4cac42e063ffaffa187dddc6fe Issue introduced in 6.7 with commit bd9d6a3efa9709e653aafbeb859289feccb8e70c and fixed in 7.2.4 with commit c1a4f7b1848f95302df598217e1c7a1410c2d0c5 Issue introduced in 6.7 with commit bd9d6a3efa9709e653aafbeb859289feccb8e70c and fixed in 7.3-rc1 with commit ae4c38555e81563b8dc5eae55ffd70f0ea97aa5a 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-2026-89691 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/nfs4xdr.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/58bcdfb2b2e412088839ae740b1a95154dc0b8d0 https://git.kernel.org/stable/c/e879148867bd4c4cac42e063ffaffa187dddc6fe https://git.kernel.org/stable/c/c1a4f7b1848f95302df598217e1c7a1410c2d0c5 https://git.kernel.org/stable/c/ae4c38555e81563b8dc5eae55ffd70f0ea97aa5a