diff --git a/pkg/sentry/fsimpl/cgroupfs/base.go b/pkg/sentry/fsimpl/cgroupfs/base.go
index 71bb0a9c8..c68085fbc 100644
--- a/pkg/sentry/fsimpl/cgroupfs/base.go
+++ b/pkg/sentry/fsimpl/cgroupfs/base.go
@@ -234,11 +234,10 @@ func (d *tasksData) Write(ctx context.Context, src usermem.IOSequence, offset in
 
 // parseInt64FromString interprets src as string encoding a int64 value, and
 // returns the parsed value.
-func parseInt64FromString(ctx context.Context, src usermem.IOSequence, offset int64) (val, len int64, err error) {
+func parseInt64FromString(ctx context.Context, src usermem.IOSequence) (val, len int64, err error) {
 	const maxInt64StrLen = 20 // i.e. len(fmt.Sprintf("%d", math.MinInt64)) == 20
 
 	t := kernel.TaskFromContext(ctx)
-	src = src.DropFirst64(offset)
 
 	buf := t.CopyScratchBuffer(maxInt64StrLen)
 	n, err := src.CopyIn(ctx, buf)
diff --git a/pkg/sentry/fsimpl/cgroupfs/cpuset.go b/pkg/sentry/fsimpl/cgroupfs/cpuset.go
index 913dde1f7..0f1990ba4 100644
--- a/pkg/sentry/fsimpl/cgroupfs/cpuset.go
+++ b/pkg/sentry/fsimpl/cgroupfs/cpuset.go
@@ -82,7 +82,6 @@ func (d *cpusData) Generate(ctx context.Context, buf *bytes.Buffer) error {
 
 // Write implements vfs.WritableDynamicBytesSource.Write.
 func (d *cpusData) Write(ctx context.Context, src usermem.IOSequence, offset int64) (int64, error) {
-	src = src.DropFirst64(offset)
 	if src.NumBytes() > hostarch.PageSize {
 		return 0, linuxerr.EINVAL
 	}
@@ -127,7 +126,6 @@ func (d *memsData) Generate(ctx context.Context, buf *bytes.Buffer) error {
 
 // Write implements vfs.WritableDynamicBytesSource.Write.
 func (d *memsData) Write(ctx context.Context, src usermem.IOSequence, offset int64) (int64, error) {
-	src = src.DropFirst64(offset)
 	if src.NumBytes() > hostarch.PageSize {
 		return 0, linuxerr.EINVAL
 	}
diff --git a/pkg/sentry/fsimpl/cgroupfs/job.go b/pkg/sentry/fsimpl/cgroupfs/job.go
index 48919c338..3b2067007 100644
--- a/pkg/sentry/fsimpl/cgroupfs/job.go
+++ b/pkg/sentry/fsimpl/cgroupfs/job.go
@@ -55,7 +55,7 @@ func (d *jobIDData) Generate(ctx context.Context, buf *bytes.Buffer) error {
 
 // Write implements vfs.WritableDynamicBytesSource.Write.
 func (d *jobIDData) Write(ctx context.Context, src usermem.IOSequence, offset int64) (int64, error) {
-	val, n, err := parseInt64FromString(ctx, src, offset)
+	val, n, err := parseInt64FromString(ctx, src)
 	if err != nil {
 		return n, err
 	}