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 5B6C73A7F5D; Thu, 15 Jan 2026 17:06:53 +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=1768496813; cv=none; b=Ysf0ylY1ZCl6/11oKOO/XGXIYcnyW9qd59jJy9DUQX4vQof058bWY06IoCZ9rIktSlYyDMrsgfNGH+VZQ6zrVFRJwD9w2XOlSqCpekeog8//dDffFrhIp03fg3jApBA4ROfwPpWh/VWIWdwWi0b6br35MLYJuhiHInud9us+zBg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768496813; c=relaxed/simple; bh=Dxmc8KeY9bBB/7AsRuOnvyF8p8lH8Eqj675cGMJPmaQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Sh8WvROOUNC8pwpDVz+Sb4mY3/J+SYg5qXEFIoUCJ5vwGPUQE4gD8tmGoRB6sAqx8NaD3muh5epCB3Hbfx+0M0g7+6sc/ch3/9GdC0/Zn+/nLvbn89iAep7BjLqgbzMYn0q+xov660Fi/XvEjNBO7Id/NWg8npz8CmU4yIV7MMo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fKNu5IGN; 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="fKNu5IGN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD4CBC116D0; Thu, 15 Jan 2026 17:06:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1768496813; bh=Dxmc8KeY9bBB/7AsRuOnvyF8p8lH8Eqj675cGMJPmaQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fKNu5IGNarXbDg29f0Z8LdB5JyHT3YIii157iEMUriUlv++OKn8ddi6nOpK+oAcXe 6tKFVcGKeoOzeXiy88iXO5gPmNBmCx49jDrwi0OHosZ2bLkxFi1P9rWSLod4ZddDZv qjM8D1QfN17IfbK6fUmCy/BQARZDVOGeCxturHw8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Trond Myklebust , Jeff Layton , NeilBrown , Chuck Lever Subject: [PATCH 6.6 24/88] nfsd: Fix NFSv3 atomicity bugs in nfsd_setattr() Date: Thu, 15 Jan 2026 17:48:07 +0100 Message-ID: <20260115164147.188341985@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260115164146.312481509@linuxfoundation.org> References: <20260115164146.312481509@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: Trond Myklebust commit 24d92de9186ebc340687caf7356e1070773e67bc upstream. The main point of the guarded SETATTR is to prevent races with other WRITE and SETATTR calls. That requires that the check of the guard time against the inode ctime be done after taking the inode lock. Furthermore, we need to take into account the 32-bit nature of timestamps in NFSv3, and the possibility that files may change at a faster rate than once a second. Signed-off-by: Trond Myklebust Reviewed-by: Jeff Layton Reviewed-by: NeilBrown Stable-dep-of: 442d27ff09a2 ("nfsd: set security label during create operations") Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfs3proc.c | 6 ++++-- fs/nfsd/nfs3xdr.c | 5 +---- fs/nfsd/nfs4proc.c | 3 +-- fs/nfsd/nfs4state.c | 2 +- fs/nfsd/nfsproc.c | 6 +++--- fs/nfsd/vfs.c | 20 +++++++++++++------- fs/nfsd/vfs.h | 2 +- fs/nfsd/xdr3.h | 2 +- 8 files changed, 25 insertions(+), 21 deletions(-) --- a/fs/nfsd/nfs3proc.c +++ b/fs/nfsd/nfs3proc.c @@ -71,13 +71,15 @@ nfsd3_proc_setattr(struct svc_rqst *rqst struct nfsd_attrs attrs = { .na_iattr = &argp->attrs, }; + const struct timespec64 *guardtime = NULL; dprintk("nfsd: SETATTR(3) %s\n", SVCFH_fmt(&argp->fh)); fh_copy(&resp->fh, &argp->fh); - resp->status = nfsd_setattr(rqstp, &resp->fh, &attrs, - argp->check_guard, argp->guardtime); + if (argp->check_guard) + guardtime = &argp->guardtime; + resp->status = nfsd_setattr(rqstp, &resp->fh, &attrs, guardtime); return rpc_success; } --- a/fs/nfsd/nfs3xdr.c +++ b/fs/nfsd/nfs3xdr.c @@ -295,17 +295,14 @@ svcxdr_decode_sattr3(struct svc_rqst *rq static bool svcxdr_decode_sattrguard3(struct xdr_stream *xdr, struct nfsd3_sattrargs *args) { - __be32 *p; u32 check; if (xdr_stream_decode_bool(xdr, &check) < 0) return false; if (check) { - p = xdr_inline_decode(xdr, XDR_UNIT * 2); - if (!p) + if (!svcxdr_decode_nfstime3(xdr, &args->guardtime)) return false; args->check_guard = 1; - args->guardtime = be32_to_cpup(p); } else args->check_guard = 0; --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1160,8 +1160,7 @@ nfsd4_setattr(struct svc_rqst *rqstp, st goto out; save_no_wcc = cstate->current_fh.fh_no_wcc; cstate->current_fh.fh_no_wcc = true; - status = nfsd_setattr(rqstp, &cstate->current_fh, &attrs, - 0, (time64_t)0); + status = nfsd_setattr(rqstp, &cstate->current_fh, &attrs, NULL); cstate->current_fh.fh_no_wcc = save_no_wcc; if (!status) status = nfserrno(attrs.na_labelerr); --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -5225,7 +5225,7 @@ nfsd4_truncate(struct svc_rqst *rqstp, s return 0; if (!(open->op_share_access & NFS4_SHARE_ACCESS_WRITE)) return nfserr_inval; - return nfsd_setattr(rqstp, fh, &attrs, 0, (time64_t)0); + return nfsd_setattr(rqstp, fh, &attrs, NULL); } static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp, --- a/fs/nfsd/nfsproc.c +++ b/fs/nfsd/nfsproc.c @@ -103,7 +103,7 @@ nfsd_proc_setattr(struct svc_rqst *rqstp } } - resp->status = nfsd_setattr(rqstp, fhp, &attrs, 0, (time64_t)0); + resp->status = nfsd_setattr(rqstp, fhp, &attrs, NULL); if (resp->status != nfs_ok) goto out; @@ -390,8 +390,8 @@ nfsd_proc_create(struct svc_rqst *rqstp) */ attr->ia_valid &= ATTR_SIZE; if (attr->ia_valid) - resp->status = nfsd_setattr(rqstp, newfhp, &attrs, 0, - (time64_t)0); + resp->status = nfsd_setattr(rqstp, newfhp, &attrs, + NULL); } out_unlock: --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -459,7 +459,6 @@ static int __nfsd_setattr(struct dentry * @rqstp: controlling RPC transaction * @fhp: filehandle of target * @attr: attributes to set - * @check_guard: set to 1 if guardtime is a valid timestamp * @guardtime: do not act if ctime.tv_sec does not match this timestamp * * This call may adjust the contents of @attr (in particular, this @@ -471,8 +470,7 @@ static int __nfsd_setattr(struct dentry */ __be32 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, - struct nfsd_attrs *attr, - int check_guard, time64_t guardtime) + struct nfsd_attrs *attr, const struct timespec64 *guardtime) { struct dentry *dentry; struct inode *inode; @@ -521,9 +519,6 @@ nfsd_setattr(struct svc_rqst *rqstp, str nfsd_sanitize_attrs(inode, iap); - if (check_guard && guardtime != inode_get_ctime_sec(inode)) - return nfserr_notsync; - /* * The size case is special, it changes the file in addition to the * attributes, and file systems don't expect it to be mixed with @@ -541,6 +536,16 @@ nfsd_setattr(struct svc_rqst *rqstp, str err = fh_fill_pre_attrs(fhp); if (err) goto out_unlock; + + if (guardtime) { + struct timespec64 ctime = inode_get_ctime(inode); + if ((u32)guardtime->tv_sec != (u32)ctime.tv_sec || + guardtime->tv_nsec != ctime.tv_nsec) { + err = nfserr_notsync; + goto out_fill_attrs; + } + } + for (retries = 1;;) { struct iattr attrs; @@ -568,6 +573,7 @@ nfsd_setattr(struct svc_rqst *rqstp, str attr->na_aclerr = set_posix_acl(&nop_mnt_idmap, dentry, ACL_TYPE_DEFAULT, attr->na_dpacl); +out_fill_attrs: fh_fill_post_attrs(fhp); out_unlock: inode_unlock(inode); @@ -1374,7 +1380,7 @@ nfsd_create_setattr(struct svc_rqst *rqs * if the attributes have not changed. */ if (iap->ia_valid) - status = nfsd_setattr(rqstp, resfhp, attrs, 0, (time64_t)0); + status = nfsd_setattr(rqstp, resfhp, attrs, NULL); else status = nfserrno(commit_metadata(resfhp)); --- a/fs/nfsd/vfs.h +++ b/fs/nfsd/vfs.h @@ -69,7 +69,7 @@ __be32 nfsd_lookup_dentry(struct svc_r const char *, unsigned int, struct svc_export **, struct dentry **); __be32 nfsd_setattr(struct svc_rqst *, struct svc_fh *, - struct nfsd_attrs *, int, time64_t); + struct nfsd_attrs *, const struct timespec64 *); int nfsd_mountpoint(struct dentry *, struct svc_export *); #ifdef CONFIG_NFSD_V4 __be32 nfsd4_vfs_fallocate(struct svc_rqst *, struct svc_fh *, --- a/fs/nfsd/xdr3.h +++ b/fs/nfsd/xdr3.h @@ -14,7 +14,7 @@ struct nfsd3_sattrargs { struct svc_fh fh; struct iattr attrs; int check_guard; - time64_t guardtime; + struct timespec64 guardtime; }; struct nfsd3_diropargs {