From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 EC1EE350A2A; Tue, 21 Oct 2025 19:58:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761076690; cv=none; b=p4KO+dkay5/l7VC/t4R0SIZC95+9hw70RRnf0tVnBkx0VzKtsEZ35NaTRolCTd2WNg0eI/A31dDPqShhCLqCWpQGoHIHlKVJX0TlpU4NSqFqNENuUBWgBCbtdCl3fLbxryTajcgRDNPrFbekQqpFHx8aZZtMiKcB1RtWZwqTdyY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761076690; c=relaxed/simple; bh=fCv3RlD/BtvkgOeL6/zXEvNzoI8q9VJmW/ND8RSpSHU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rQmG5aQkMceE/USqc9Se2++82yY+R/3lfq9uPTkJ05HMSYrnUIsFe6CMRQdn/n5jQIq6TjpNI1SoB2GYSFamUnULugcDgZ6ad7djdcqN9iN7Qqn6CRxvL83vqYem1GIa7FMDQFsXrPyoturH+8NWfUD1F3qiSm3qw75Gl7mpXsE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=P3W9vTaW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="P3W9vTaW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6B1E8C4CEF1; Tue, 21 Oct 2025 19:58:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1761076689; bh=fCv3RlD/BtvkgOeL6/zXEvNzoI8q9VJmW/ND8RSpSHU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=P3W9vTaWycyyJry4svmckl4Grlhte0j+NeNqKL6ZqsVk13eaN9aIHnJVxAw/gKu4M e9TqFLCySx2H8NZGmD0Ppr+t2UjF2UGw9r/Iq+kjEwj9DRK2ry+aA1nFIoKNEAFESj 171QmeXfiRha6e49+2+gJ9+WfVlmu/GDJ9PqXOuI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, chuck.lever@oracle.com, Scott Mayhew Subject: [PATCH 6.6 099/105] nfsd: decouple the xprtsec policy check from check_nfsd_access() Date: Tue, 21 Oct 2025 21:51:48 +0200 Message-ID: <20251021195024.004492578@linuxfoundation.org> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20251021195021.492915002@linuxfoundation.org> References: <20251021195021.492915002@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Scott Mayhew [ Upstream commit e4f574ca9c6dfa66695bb054ff5df43ecea873ec ] This is a backport of e4f574ca9c6d specifically for the 6.6-stable kernel. It differs from the upstream version mainly in that it's working around the absence of some 6.12-era commits: - 1459ad57673b nfsd: Move error code mapping to per-version proc code. - 0a183f24a7ae NFSD: Handle @rqstp == NULL in check_nfsd_access() - 5e66d2d92a1c nfsd: factor out __fh_verify to allow NULL rqstp to be passed A while back I had reported that an NFSv3 client could successfully mount using '-o xprtsec=none' an export that had been exported with 'xprtsec=tls:mtls'. By "successfully" I mean that the mount command would succeed and the mount would show up in /proc/mount. Attempting to do anything futher with the mount would be met with NFS3ERR_ACCES. Transport Layer Security isn't an RPC security flavor or pseudo-flavor, so we shouldn't be conflating them when determining whether the access checks can be bypassed. Split check_nfsd_access() into two helpers, and have fh_verify() call the helpers directly since fh_verify() has logic that allows one or both of the checks to be skipped. All other sites will continue to call check_nfsd_access(). Link: https://lore.kernel.org/linux-nfs/ZjO3Qwf_G87yNXb2@aion/ Fixes: 9280c5774314 ("NFSD: Handle new xprtsec= export option") Signed-off-by: Scott Mayhew Acked-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/export.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++-------- fs/nfsd/export.h | 2 + fs/nfsd/nfsfh.c | 12 ++++++++++- 3 files changed, 65 insertions(+), 9 deletions(-) --- a/fs/nfsd/export.c +++ b/fs/nfsd/export.c @@ -1071,28 +1071,62 @@ static struct svc_export *exp_find(struc return exp; } -__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp) +/** + * check_xprtsec_policy - check if access to export is allowed by the + * xprtsec policy + * @exp: svc_export that is being accessed. + * @rqstp: svc_rqst attempting to access @exp. + * + * Helper function for check_nfsd_access(). Note that callers should be + * using check_nfsd_access() instead of calling this function directly. The + * one exception is fh_verify() since it has logic that may result in one + * or both of the helpers being skipped. + * + * Return values: + * %nfs_ok if access is granted, or + * %nfserr_acces or %nfserr_wrongsec if access is denied + */ +__be32 check_xprtsec_policy(struct svc_export *exp, struct svc_rqst *rqstp) { - struct exp_flavor_info *f, *end = exp->ex_flavors + exp->ex_nflavors; struct svc_xprt *xprt = rqstp->rq_xprt; if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_NONE) { if (!test_bit(XPT_TLS_SESSION, &xprt->xpt_flags)) - goto ok; + return nfs_ok; } if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_TLS) { if (test_bit(XPT_TLS_SESSION, &xprt->xpt_flags) && !test_bit(XPT_PEER_AUTH, &xprt->xpt_flags)) - goto ok; + return nfs_ok; } if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_MTLS) { if (test_bit(XPT_TLS_SESSION, &xprt->xpt_flags) && test_bit(XPT_PEER_AUTH, &xprt->xpt_flags)) - goto ok; + return nfs_ok; } - goto denied; -ok: + return rqstp->rq_vers < 4 ? nfserr_acces : nfserr_wrongsec; +} + +/** + * check_security_flavor - check if access to export is allowed by the + * xprtsec policy + * @exp: svc_export that is being accessed. + * @rqstp: svc_rqst attempting to access @exp. + * + * Helper function for check_nfsd_access(). Note that callers should be + * using check_nfsd_access() instead of calling this function directly. The + * one exception is fh_verify() since it has logic that may result in one + * or both of the helpers being skipped. + * + * Return values: + * %nfs_ok if access is granted, or + * %nfserr_acces or %nfserr_wrongsec if access is denied + */ +__be32 check_security_flavor(struct svc_export *exp, struct svc_rqst *rqstp) +{ + struct exp_flavor_info *f, *end = exp->ex_flavors + exp->ex_nflavors; + /* legacy gss-only clients are always OK: */ if (exp->ex_client == rqstp->rq_gssclient) return 0; @@ -1117,10 +1151,20 @@ ok: if (nfsd4_spo_must_allow(rqstp)) return 0; -denied: return rqstp->rq_vers < 4 ? nfserr_acces : nfserr_wrongsec; } +__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp) +{ + __be32 status; + + status = check_xprtsec_policy(exp, rqstp); + if (status != nfs_ok) + return status; + + return check_security_flavor(exp, rqstp); +} + /* * Uses rq_client and rq_gssclient to find an export; uses rq_client (an * auth_unix client) if it's available and has secinfo information; --- a/fs/nfsd/export.h +++ b/fs/nfsd/export.h @@ -100,6 +100,8 @@ struct svc_expkey { #define EX_WGATHER(exp) ((exp)->ex_flags & NFSEXP_GATHERED_WRITES) int nfsexp_flags(struct svc_rqst *rqstp, struct svc_export *exp); +__be32 check_xprtsec_policy(struct svc_export *exp, struct svc_rqst *rqstp); +__be32 check_security_flavor(struct svc_export *exp, struct svc_rqst *rqstp); __be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp); /* --- a/fs/nfsd/nfsfh.c +++ b/fs/nfsd/nfsfh.c @@ -371,6 +371,16 @@ fh_verify(struct svc_rqst *rqstp, struct goto out; /* + * NLM is allowed to bypass the xprtsec policy check because lockd + * doesn't support xprtsec. + */ + if (!(access & NFSD_MAY_LOCK)) { + error = check_xprtsec_policy(exp, rqstp); + if (error) + goto out; + } + + /* * pseudoflavor restrictions are not enforced on NLM, * which clients virtually always use auth_sys for, * even while using RPCSEC_GSS for NFS. @@ -386,7 +396,7 @@ fh_verify(struct svc_rqst *rqstp, struct && exp->ex_path.dentry == dentry) goto skip_pseudoflavor_check; - error = check_nfsd_access(exp, rqstp); + error = check_security_flavor(exp, rqstp); if (error) goto out;