5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Stefan Hajnoczi stefanha@redhat.com
[ Upstream commit 40488cc16f7ea0d193a4e248f0d809c25cc377db ]
Newlines in virtiofs tags are awkward for users and potential vectors for string injection attacks.
Signed-off-by: Stefan Hajnoczi stefanha@redhat.com Reviewed-by: Vivek Goyal vgoyal@redhat.com Signed-off-by: Miklos Szeredi mszeredi@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/fuse/virtio_fs.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c index 94fc874f5de7f..a4deacc6f78c7 100644 --- a/fs/fuse/virtio_fs.c +++ b/fs/fuse/virtio_fs.c @@ -310,6 +310,16 @@ static int virtio_fs_read_tag(struct virtio_device *vdev, struct virtio_fs *fs) return -ENOMEM; memcpy(fs->tag, tag_buf, len); fs->tag[len] = '\0'; + + /* While the VIRTIO specification allows any character, newlines are + * awkward on mount(8) command-lines and cause problems in the sysfs + * "tag" attr and uevent TAG= properties. Forbid them. + */ + if (strchr(fs->tag, '\n')) { + dev_dbg(&vdev->dev, "refusing virtiofs tag with newline character\n"); + return -EINVAL; + } + return 0; }