FAILED: patch "[PATCH] nfsd: reject out-of-range nseconds in NFSv3 SETATTR and" failed to apply to 5.10-stable tree

The patch below does not apply to the 5.10-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 <[email protected]>.

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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x eb0eca7720662ba5847df1510e73801f7f473094
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026090308-framing-charity-2ed8@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From eb0eca7720662ba5847df1510e73801f7f473094 Mon Sep 17 00:00:00 2001
From: Robbie Ko <[email protected]>
Date: Tue, 16 Jun 2026 13:39:59 +0800
Subject: [PATCH] nfsd: reject out-of-range nseconds in NFSv3 SETATTR and
create ops

A client can send an NFSv3 SETATTR, CREATE, MKDIR, SYMLINK or MKNOD carrying an atime or mtime whose nseconds field is out of range. The value is well-formed on the wire and decodes cleanly into a valid uint32, but it is not a valid timespec64: tv_nsec must be less than NSEC_PER_SEC.

Nothing in the setattr path clamps it. notify_change() runs the time through timestamp_truncate(), which does not reduce tv_nsec below NSEC_PER_SEC when the filesystem supports nanosecond granularity (s_time_gran == 1), and the inode atime/mtime setters store it verbatim (only ctime is normalized, via inode_set_ctime_to_ts()). The un-normalized value then corrupts on-disk metadata: ext4's ext4_encode_extra_time() shifts tv_nsec left by EXT4_EPOCH_BITS, which overflows the 32-bit extra field and clobbers the seconds-epoch bits, so the stored seconds (and thus the year) are wrong on read-back. XFS with bigtime mis-stores the timestamp for the same reason.

Validate the client-supplied atime/mtime in the proc handlers and return NFS3ERR_INVAL before anything is changed. RFC 1813 lists NFS3ERR_INVAL for SETATTR and describes it as the error for a value the server 'can not store ... in its own representation'; the client maps it to EINVAL.

Checking in the proc handlers, rather than in nfsd_setattr(), keeps the rejection in front of object creation. The create operations create the object before nfsd_create_setattr() runs, so a late failure would leave the new object behind and turn a non-idempotent request into a namespace change that reports failure. The check is therefore done up front, for the create operations before the object is created.

tv_nsec is a long, so the comparison casts it to unsigned long (the same width) rather than to u32, matching timespec64_valid(). A u32 cast would truncate on 64-bit; the unsigned long cast also rejects a value that became negative when an out-of-range u32 wire nseconds was assigned to a 32-bit long.

Only client-supplied times are checked: SET_TO_SERVER_TIME requests carry no client value. The sattrguard3 ctime is deliberately left alone:
an out-of-range guard simply never matches the object's ctime and yields NFS3ERR_NOT_SYNC via the existing guardtime comparison, which is the protocol-correct outcome rather than rejecting the request.

index aeda7a802bdf..617a70d13292 100644
@@ -29,6 +29,25 @@ static int	nfs3_ftypes[] = {
 	S_IFIFO,		/* NF3FIFO */
 };
 
+/*
+ * Reject a client-supplied atime or mtime whose nanoseconds field is out
+ * of range. Such a value is well-formed on the wire but is not a valid
+ * timespec64, and storing it verbatim can corrupt on-disk timestamps.
+ * tv_nsec is a long, so it is cast to unsigned long (the same width) to
+ * catch both an over-large value and one that became negative when an
+ * out-of-range u32 wire nseconds was assigned to a 32-bit long.
+ */
+static bool nfsd3_time_in_range(const struct iattr *iap)
+{
+	if ((iap->ia_valid & ATTR_ATIME_SET) &&
+	    (unsigned long)iap->ia_atime.tv_nsec >= NSEC_PER_SEC)
+		return false;
+	if ((iap->ia_valid & ATTR_MTIME_SET) &&
+	    (unsigned long)iap->ia_mtime.tv_nsec >= NSEC_PER_SEC)
+		return false;
+	return true;
+}
+
 static __be32 nfsd3_map_status(__be32 status)
 {
 	switch (status) {

@@ -101,9 +120,14 @@ nfsd3_proc_setattr(struct svc_rqst *rqstp)
 				SVCFH_fmt(&argp->fh));
 
 	fh_copy(&resp->fh, &argp->fh);
+	if (!nfsd3_time_in_range(&argp->attrs)) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
 	if (argp->check_guard)
 		guardtime = &argp->guardtime;
 	resp->status = nfsd_setattr(rqstp, &resp->fh, &attrs, guardtime);
+out:
 	resp->status = nfsd3_map_status(resp->status);
 	return rpc_success;
 }

@@ -265,6 +289,8 @@ nfsd3_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
 
 	trace_nfsd_vfs_create(rqstp, fhp, S_IFREG, argp->name, argp->len);
 
+	if (!nfsd3_time_in_range(iap))
+		return nfserr_inval;
 	if (isdotent(argp->name, argp->len))
 		return nfserr_exist;
 	if (!(iap->ia_valid & ATTR_MODE))

@@ -400,8 +426,13 @@ nfsd3_proc_mkdir(struct svc_rqst *rqstp)
 	argp->attrs.ia_valid &= ~ATTR_SIZE;
 	fh_copy(&resp->dirfh, &argp->fh);
 	fh_init(&resp->fh, NFS3_FHSIZE);
+	if (!nfsd3_time_in_range(&argp->attrs)) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
 	resp->status = nfsd_create(rqstp, &resp->dirfh, argp->name, argp->len,
 				   &attrs, S_IFDIR, 0, &resp->fh);
+out:
 	resp->status = nfsd3_map_status(resp->status);
 	return rpc_success;
 }

@@ -415,6 +446,10 @@ nfsd3_proc_symlink(struct svc_rqst *rqstp)
 		.na_iattr	= &argp->attrs,
 	};
 
+	if (!nfsd3_time_in_range(&argp->attrs)) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
 	if (argp->tlen == 0) {
 		resp->status = nfserr_inval;
 		goto out;

@@ -471,6 +506,11 @@ nfsd3_proc_mknod(struct svc_rqst *rqstp)
 		goto out;
 	}
 
+	if (!nfsd3_time_in_range(&argp->attrs)) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
+
 	type = nfs3_ftypes[argp->ftype];
 	resp->status = nfsd_create(rqstp, &resp->dirfh, argp->name, argp->len,
 				   &attrs, type, rdev, &resp->fh);

From: Robbie Ko <[email protected]>

[ Upstream commit eb0eca7720662ba5847df1510e73801f7f473094 ]

A client can send an NFSv3 SETATTR, CREATE, MKDIR, SYMLINK or MKNOD carrying an atime or mtime whose nseconds field is out of range. The value is well-formed on the wire and decodes cleanly into a valid uint32, but it is not a valid timespec64: tv_nsec must be less than NSEC_PER_SEC.

Nothing in the setattr path clamps it. notify_change() runs the time through timestamp_truncate(), which does not reduce tv_nsec below NSEC_PER_SEC when the filesystem supports nanosecond granularity (s_time_gran == 1), and the inode atime/mtime setters store it verbatim (only ctime is normalized, via inode_set_ctime_to_ts()). The un-normalized value then corrupts on-disk metadata: ext4's ext4_encode_extra_time() shifts tv_nsec left by EXT4_EPOCH_BITS, which overflows the 32-bit extra field and clobbers the seconds-epoch bits, so the stored seconds (and thus the year) are wrong on read-back. XFS with bigtime mis-stores the timestamp for the same reason.

Validate the client-supplied atime/mtime in the proc handlers and return NFS3ERR_INVAL before anything is changed. RFC 1813 lists NFS3ERR_INVAL for SETATTR and describes it as the error for a value the server 'can not store ... in its own representation'; the client maps it to EINVAL.

Checking in the proc handlers, rather than in nfsd_setattr(), keeps the rejection in front of object creation. The create operations create the object before nfsd_create_setattr() runs, so a late failure would leave the new object behind and turn a non-idempotent request into a namespace change that reports failure. The check is therefore done up front, for the create operations before the object is created.

tv_nsec is a long, so the comparison casts it to unsigned long (the same width) rather than to u32, matching timespec64_valid(). A u32 cast would truncate on 64-bit; the unsigned long cast also rejects a value that became negative when an out-of-range u32 wire nseconds was assigned to a 32-bit long.

Only client-supplied times are checked: SET_TO_SERVER_TIME requests carry no client value. The sattrguard3 ctime is deliberately left alone:
an out-of-range guard simply never matches the object's ctime and yields NFS3ERR_NOT_SYNC via the existing guardtime comparison, which is the protocol-correct outcome rather than rejecting the request.

---
 fs/nfsd/nfs3proc.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

index 19cf583096d9c..6c5a5fd4caa58 100644
@@ -76,6 +76,13 @@ nfsd3_proc_setattr(struct svc_rqst *rqstp)
 				SVCFH_fmt(&argp->fh));
 
 	fh_copy(&resp->fh, &argp->fh);
+	if (((argp->attrs.ia_valid & ATTR_ATIME_SET) &&
+	     (unsigned long)argp->attrs.ia_atime.tv_nsec >= NSEC_PER_SEC) ||
+	    ((argp->attrs.ia_valid & ATTR_MTIME_SET) &&
+	     (unsigned long)argp->attrs.ia_mtime.tv_nsec >= NSEC_PER_SEC)) {
+		resp->status = nfserr_inval;
+		return rpc_success;
+	}
 	resp->status = nfsd_setattr(rqstp, &resp->fh, &attrs,
 				    argp->check_guard, argp->guardtime);
 	return rpc_success;

@@ -245,6 +252,11 @@ nfsd3_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	__be32 status;
 	int host_err;
 
+	if (((iap->ia_valid & ATTR_ATIME_SET) &&
+	     (unsigned long)iap->ia_atime.tv_nsec >= NSEC_PER_SEC) ||
+	    ((iap->ia_valid & ATTR_MTIME_SET) &&
+	     (unsigned long)iap->ia_mtime.tv_nsec >= NSEC_PER_SEC))
+		return nfserr_inval;
 	if (isdotent(argp->name, argp->len))
 		return nfserr_exist;
 	if (!(iap->ia_valid & ATTR_MODE))

@@ -389,6 +401,13 @@ nfsd3_proc_mkdir(struct svc_rqst *rqstp)
 	argp->attrs.ia_valid &= ~ATTR_SIZE;
 	fh_copy(&resp->dirfh, &argp->fh);
 	fh_init(&resp->fh, NFS3_FHSIZE);
+	if (((argp->attrs.ia_valid & ATTR_ATIME_SET) &&
+	     (unsigned long)argp->attrs.ia_atime.tv_nsec >= NSEC_PER_SEC) ||
+	    ((argp->attrs.ia_valid & ATTR_MTIME_SET) &&
+	     (unsigned long)argp->attrs.ia_mtime.tv_nsec >= NSEC_PER_SEC)) {
+		resp->status = nfserr_inval;
+		return rpc_success;
+	}
 	resp->status = nfsd_create(rqstp, &resp->dirfh, argp->name, argp->len,
 				   &attrs, S_IFDIR, 0, &resp->fh);
 	return rpc_success;

@@ -403,6 +422,13 @@ nfsd3_proc_symlink(struct svc_rqst *rqstp)
 		.na_iattr	= &argp->attrs,
 	};
 
+	if (((argp->attrs.ia_valid & ATTR_ATIME_SET) &&
+	     (unsigned long)argp->attrs.ia_atime.tv_nsec >= NSEC_PER_SEC) ||
+	    ((argp->attrs.ia_valid & ATTR_MTIME_SET) &&
+	     (unsigned long)argp->attrs.ia_mtime.tv_nsec >= NSEC_PER_SEC)) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
 	if (argp->tlen == 0) {
 		resp->status = nfserr_inval;
 		goto out;

@@ -468,6 +494,14 @@ nfsd3_proc_mknod(struct svc_rqst *rqstp)
 		goto out;
 	}
 
+	if (((argp->attrs.ia_valid & ATTR_ATIME_SET) &&
+	     (unsigned long)argp->attrs.ia_atime.tv_nsec >= NSEC_PER_SEC) ||
+	    ((argp->attrs.ia_valid & ATTR_MTIME_SET) &&
+	     (unsigned long)argp->attrs.ia_mtime.tv_nsec >= NSEC_PER_SEC)) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
+
 	type = nfs3_ftypes[argp->ftype];
 	resp->status = nfsd_create(rqstp, &resp->dirfh, argp->name, argp->len,
 				   &attrs, type, rdev, &resp->fh);

2.53.0