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 8EDFE4483A1 for ; Thu, 3 Sep 2026 13:18:57 +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=1788441547; cv=none; b=QvSMGY4eSlayegOEybKn/+lQVhkNJ5aTZH++WDlGVHAVo8AKa7CG1svYk5URMcGvbsLc3Y79pDYWczapnuccx5bP042GuMqNFie97b9cu8xOT4venMjOQbBnoe9eVvEFCm4JxwQJO6onHwqdbkUipTM8h3SYub1UPEiNYC5T6oM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788441547; c=relaxed/simple; bh=pORN9a666Krqf9vOnQLmxbCcLcB4KAGymoTNayjn8tg=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=ajVBXf1m8bSxoHD5EHqF7RdywpoYUh62AgJ2MWdat4G7UbpD542k/ov3q7F/JuGiarVI656f4wUsL3Lt+HdOw6vhf9+qK9rUT6U4u9aaGPe4mn9rHlVhBRKD+N6zY6Ig55AO6hgRJnJQeInONLfrfHTwMDGKlINl+zy9HhW6t0E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=EVOnRPiq; 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="EVOnRPiq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1F2831F00ACA; Thu, 3 Sep 2026 13:18:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788441534; bh=4bnkunhXuIUseD54oUyrPykqDvQqew4wmt2OXDVlgQA=; h=Subject:To:Cc:From:Date; b=EVOnRPiqV3SjIL1aZiOYaQ/jzpHIsMX3SXdoz4kSwoWaDPnfIiXF41j99H3c8Ki7L pJzjZR6EJZ02VL/1fV/Avli4BN/CtP0TyidFBcb6NZoSVFlw44caXJeg1ETpLJz7K5 cR2NNg1plp3xO+Zq5rxxWu5A3dbPqoTlP4Ygs3t4= Subject: FAILED: patch "[PATCH] nfsd: validate sockaddr length per family in listener_set" failed to apply to 6.12-stable tree To: jlayton@kernel.org,cel@kernel.org Cc: From: Date: Thu, 03 Sep 2026 15:11:27 +0200 Message-ID: <2026090327-bully-unsightly-dc1a@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x bdcc85c2b05a9378d8bd2d65f9fc41440a3cf464 # git commit -s git send-email --to '' --in-reply-to '2026090327-bully-unsightly-dc1a@gregkh' --subject-prefix 'PATCH 6.12.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From bdcc85c2b05a9378d8bd2d65f9fc41440a3cf464 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Mon, 15 Jun 2026 14:31:25 -0400 Subject: [PATCH] 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. Fixes: 16a471177496 ("NFSD: add listener-{set,get} netlink command") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Jeff Layton Link: https://patch.msgid.link/20260615-nfsd-testing-v5-1-188d75aedda0@kernel.org Signed-off-by: Chuck Lever diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index f1ecbb13f642..caf59421f8f4 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -1971,6 +1971,60 @@ int nfsd_nl_version_get_doit(struct sk_buff *skb, struct genl_info *info) return err; } +/** + * nfsd_nl_validate_listeners - sanity-check the listener list from userland + * @info: netlink metadata and command arguments + * + * Walk every NFSD_A_SERVER_SOCK_ADDR attribute and confirm that each entry + * is well-formed: it parses against the policy, carries both an address and + * a transport name, and the address is long enough for its family. Doing + * this up front lets the callers below assume every entry is valid and + * guarantees we make no changes when the request is malformed. + * + * Return: 0 if every entry is valid, or a negative errno otherwise. + */ +static int nfsd_nl_validate_listeners(struct genl_info *info) +{ + const struct nlattr *attr; + int rem; + + nlmsg_for_each_attr_type(attr, NFSD_A_SERVER_SOCK_ADDR, info->nlhdr, + GENL_HDRLEN, rem) { + struct nlattr *tb[NFSD_A_SOCK_MAX + 1]; + struct sockaddr *sa; + int err; + + err = nla_parse_nested(tb, NFSD_A_SOCK_MAX, attr, + nfsd_sock_nl_policy, info->extack); + if (err < 0) + return err; + + if (!tb[NFSD_A_SOCK_ADDR] || !tb[NFSD_A_SOCK_TRANSPORT_NAME]) + return -EINVAL; + + sa = nla_data(tb[NFSD_A_SOCK_ADDR]); + if (nla_len(tb[NFSD_A_SOCK_ADDR]) < sizeof(sa->sa_family)) + return -EINVAL; + + switch (sa->sa_family) { + case AF_INET: + if (nla_len(tb[NFSD_A_SOCK_ADDR]) < + sizeof(struct sockaddr_in)) + return -EINVAL; + break; + case AF_INET6: + if (nla_len(tb[NFSD_A_SOCK_ADDR]) < + sizeof(struct sockaddr_in6)) + return -EINVAL; + break; + default: + return -EAFNOSUPPORT; + } + } + + return 0; +} + /** * nfsd_nl_listener_set_doit - set the nfs running sockets * @skb: reply buffer @@ -1989,6 +2043,15 @@ int nfsd_nl_listener_set_doit(struct sk_buff *skb, struct genl_info *info) bool delete = false; int err, rem; + /* + * Validate the entire listener list before making any changes, so a + * malformed request fails cleanly without creating a serv or touching + * the existing listeners. + */ + err = nfsd_nl_validate_listeners(info); + if (err) + return err; + mutex_lock(&nfsd_mutex); err = nfsd_create_serv(net); @@ -2015,16 +2078,11 @@ int nfsd_nl_listener_set_doit(struct sk_buff *skb, struct genl_info *info) const char *xcl_name; struct sockaddr *sa; + /* validated up front in nfsd_nl_validate_listeners() */ if (nla_parse_nested(tb, NFSD_A_SOCK_MAX, attr, nfsd_sock_nl_policy, info->extack) < 0) continue; - if (!tb[NFSD_A_SOCK_ADDR] || !tb[NFSD_A_SOCK_TRANSPORT_NAME]) - continue; - - if (nla_len(tb[NFSD_A_SOCK_ADDR]) < sizeof(*sa)) - continue; - xcl_name = nla_data(tb[NFSD_A_SOCK_TRANSPORT_NAME]); sa = nla_data(tb[NFSD_A_SOCK_ADDR]); @@ -2076,16 +2134,11 @@ int nfsd_nl_listener_set_doit(struct sk_buff *skb, struct genl_info *info) struct sockaddr *sa; int ret; + /* validated up front in nfsd_nl_validate_listeners() */ if (nla_parse_nested(tb, NFSD_A_SOCK_MAX, attr, nfsd_sock_nl_policy, info->extack) < 0) continue; - if (!tb[NFSD_A_SOCK_ADDR] || !tb[NFSD_A_SOCK_TRANSPORT_NAME]) - continue; - - if (nla_len(tb[NFSD_A_SOCK_ADDR]) < sizeof(*sa)) - continue; - xcl_name = nla_data(tb[NFSD_A_SOCK_TRANSPORT_NAME]); sa = nla_data(tb[NFSD_A_SOCK_ADDR]);