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 3EFA635CB7C; Fri, 4 Sep 2026 05:43:29 +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=1788500610; cv=none; b=iTyG9ExqzAjk3fILtsAzL9IxqLlJwXoDmj+5SWxDLs6FZdlaZ42OnojarpbNO5A1uLsO3c0lIMoq+pZKtwSUwrNLTU/j1fZFG4elrvCF/7QLhTsFNszmX86t8IV+Mo3sYMfa6LPIru0L5fOsywA9nCM+4oITdXkQa4VZzcPLO1U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788500610; c=relaxed/simple; bh=68icwM3G1dUNhyJ58tJ1Lm+x/ke7ESpwJBBzU9TxWAw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hzl3wKnA5iGKDcXpl+Yyj8gVxVullrdFsPxqvtNPH2LpXTT6RIl71Q8q4af+EP7hXhGfU7hxQbaAuxhoxaVnnqyE4pc/jxI2EdDQAsTe8uU3BumJ/Z78um7yej3iDv2ODxWkC6uUloCLGiNGc5IquqKEAgjLR25qMcpXcW2T/Yw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=pO6Eps5c; 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="pO6Eps5c" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 985B01F00A3D; Fri, 4 Sep 2026 05:43:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788500609; bh=fhGPaulQWlPu2M8FfOV0KdABA+tZ20lsk82FJwmRQSk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=pO6Eps5cyjS7JqYYZTIcfgTl/IUzPy4YO9purx99VCnekivtslFrtuQ/FiEauMYCN DarQ3w6chsGlTicE+BuPqRxiKP+xslPdyUMNxmCh0jHXKb48+4EeEYJKG5gIyzSqoQ jgsMYT3YVvK0KPjzKSXXkQN6a6vUnYtm5RwJ/Bsc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jeff Layton , Chuck Lever Subject: [PATCH 6.18 115/552] nfsd: validate sockaddr length per family in listener_set Date: Fri, 4 Sep 2026 06:54:32 +0200 Message-ID: <20260904045750.552778541@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045747.813364717@linuxfoundation.org> References: <20260904045747.813364717@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeff Layton commit bdcc85c2b05a9378d8bd2d65f9fc41440a3cf464 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfsctl.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 65 insertions(+), 12 deletions(-) --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -1876,6 +1876,60 @@ err_free_msg: } /** + * 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 * @info: netlink metadata and command arguments @@ -1893,6 +1947,15 @@ int nfsd_nl_listener_set_doit(struct sk_ 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); @@ -1919,16 +1982,11 @@ int nfsd_nl_listener_set_doit(struct sk_ 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]); @@ -1980,16 +2038,11 @@ int nfsd_nl_listener_set_doit(struct sk_ 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]);