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 B106758FD29 for ; Fri, 11 Sep 2026 20:03:39 +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=1789157032; cv=none; b=RHPlBMQQ0OQVUmCT7ZItv8JJtgDQiFWNjkxM4F5ST9nVB4ZM1ruR9QmpaD7WuwuRdcExOLcM/Qx6LWBszmf7t6VUMJAUGI2usV1fNJDPOKPp6m0BenasFcq66GKCZ+PigpJ895JiCVvVbbNMMyoE4ztQoUSpFBoRF3OUztaqvO0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789157032; c=relaxed/simple; bh=w5JSZT+P3+lPNG+g3I//M/7NDgN6a+HbOFF/c4bPjf8=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=PPXNgtOujtL1h2M0tLQGCyyBKQfcvAAbo+BT+nKdxiMbILUx7kVZe2fFk1Jl6w3so+T2QDx+a7jLcO9o+KVH+7ECioLAR+3k0kS5QOs29nCLRRyOsc/haepzhTVS2BWsZ9scXMcXYNK2xXEtFlGZnj3YTzFbLttGNZk+L0BREFw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=w01xnuRZ; 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="w01xnuRZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C5DA1F00898; Fri, 11 Sep 2026 20:03:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789157012; bh=U25jYsk6eGvjt1FZIRwdpi3Y7X4fzX2RtDa44b7XPuQ=; h=From:To:Cc:Subject:Date:Reply-To; b=w01xnuRZ8S98RQGm86NpyE+j3umYYodh61i3L66fYr4YGmRYsVKRr/Woki+PK2RE+ eSOzonrYFC1tBODQcrG5chnbFlgcpE8qt7a1Vg8T5C5rht8tgVE4J93fKPazJviXwN ZkXLyjQgI62/cqUxeJztBbI5n6lrPAn5XV5B35g0= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89700: nfsd: validate sockaddr length per family in listener_set Date: Fri, 11 Sep 2026 21:46:29 +0200 Message-ID: <2026091155-CVE-2026-89700-76a7@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=3302; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=W7RFfnH5YreJzGKKfx7dcPha7atDO3KaLWNWp4vSpLQ=; b=kA0DAAIRMUfUDdst+ykByyZiAGqkWYPIC1CJ8UxNN7BgPnfs/uNkK4cuOfLGTfhXkK9lBqcRF ohdBAARAgAdFiEE9LYMxb94wiFKMT3LMUfUDdst+ykFAmqkWYMACgkQMUfUDdst+ymvpACgmN+y 2xk50//Gvhktog5znN5lUWQAmwdcmOGGwIbT6kDRNU96G23/kj5g 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: validate sockaddr length per family in listener_set nfsd_sock_nl_policy declares NFSD_A_SOCK_ADDR as a bare NLA_BINARY attribute with no minimum length. A CAP_NET_ADMIN caller can send a 16-byte NFSD_A_SOCK_ADDR with sa_family=AF_INET6, causing a 12-byte OOB read across three consumers (rpc_cmp_addr_port, svc_find_listener, kernel_bind). nfsd_nl_listener_set_doit() also parsed and validated each listener entry inline in two separate loops, interleaved with mutating the running listener configuration. The validation was duplicated, used an open-coded "nla_len < sizeof(struct sockaddr)" check that was too short for AF_INET6, and handled a malformed entry inconsistently depending on which loop noticed it. Add an nfsd_nl_validate_listeners() helper that walks the entire list once and confirms each entry parses, carries both an address and a transport name, and is long enough for its address family (sizeof(struct sockaddr_in) for AF_INET, sizeof(struct sockaddr_in6) for AF_INET6, -EAFNOSUPPORT otherwise). Call it before taking nfsd_mutex or creating the serv, so a malformed request fails cleanly with no side effects. Since every entry is known valid by the time the two existing loops run, drop the redundant presence and per-family length checks from both, leaving only the nla_parse_nested() call needed to extract the data. The Linux kernel CVE team has assigned CVE-2026-89700 to this issue. Affected and fixed versions =========================== Issue introduced in 6.10 with commit 16a471177496c8e04a9793812c187a2c1a2192fa and fixed in 6.18.50 with commit 2aca70c18c5f5d06004122861fb151d5fcc57faf Issue introduced in 6.10 with commit 16a471177496c8e04a9793812c187a2c1a2192fa and fixed in 7.2.4 with commit 22d0e4752ca88fd84196d22ebeedc905e6540440 Issue introduced in 6.10 with commit 16a471177496c8e04a9793812c187a2c1a2192fa and fixed in 7.3-rc1 with commit bdcc85c2b05a9378d8bd2d65f9fc41440a3cf464 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-2026-89700 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/nfsctl.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/2aca70c18c5f5d06004122861fb151d5fcc57faf https://git.kernel.org/stable/c/22d0e4752ca88fd84196d22ebeedc905e6540440 https://git.kernel.org/stable/c/bdcc85c2b05a9378d8bd2d65f9fc41440a3cf464