netns: Make get_net_ns() handle zero refcount net

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/core/net_namespace.c"
                    ],
                    "versions": [
                        {
                            "version": "0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f",
                            "lessThan": "3a6cd326ead7c8bb1f64486789a01974a9f1ad55",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f",
                            "lessThan": "2b82028a1f5ee3a8e04090776b10c534144ae77b",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f",
                            "lessThan": "cb7f811f638a14590ff98f53c6dd1fb54627d940",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f",
                            "lessThan": "1b631bffcb2c09551888f3c723f4365c91fe05ef",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f",
                            "lessThan": "ef0394ca25953ea0eddcc82feae1f750451f1876",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f",
                            "lessThan": "3af28df0d883e8c89a29ac31bc65f9023485743b",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f",
                            "lessThan": "ff960f9d3edbe08a736b5a224d91a305ccc946b0",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                }

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/core/net_namespace.c"
                    ],
                    "versions": [
                        {
                            "version": "5.2",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.2",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.4.279",
                            "lessThanOrEqual": "5.4.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.10.221",
                            "lessThanOrEqual": "5.10.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.15.162",
                            "lessThanOrEqual": "5.15.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.96",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.36",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.9.7",
                            "lessThanOrEqual": "6.9.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.10",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }