CVE-2026-99244

pid_namespace: prevent TIF_NOTIFY_SIGNAL from interrupting the reaper

cve-program · severity unknownCVSS unknownCheck source for fixed versionsKEV status unknown

Original advisory

cve-program · CVE-2026-99244

Published

In the Linux kernel, the following vulnerability has been resolved: pid_namespace: prevent TIF_NOTIFY_SIGNAL from interrupting the reaper Since commit 7fea700e04bd ("zap_pid_ns_processes: clear TIF_NOTIFY_SIGNAL along with TIF_SIGPENDING") zap_pid_ns_processes() clears TIF_NOTIFY_SIGNAL before every kernel_wait4() call. Otherwise kernel_wait4() doesn't sleep and returns -ERESTARTSYS if signal_pending() is true and the reaper busy-waits. But clearing TIF_NOTIFY_SIGNAL doesn't fix it. It can get raised again. For example, klp_send_signals() sets it raw against any task that hasn't transitioned yet. And it keeps sending it until the livepatch finishes. The sleep loop waiting for pid_allocated to drop has the same problem and it doesn't even clear anything. So a schedule() in TASK_INTERRUPTIBLE returns immediately. Use a no_notify_signal guard. signal_pending() will ignore TIF_NOTIFY_SIGNAL and the pid namespace reaper sleeps until a child exits or free_pid() wakes it.

Read the publisher's advisory

Affected versions, risk and source history

cve-program · CVE-2026-99244

Published

Linux

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/pid_namespace.c"
                    ],
                    "versions": [
                        {
                            "version": "edd2754a62bee8d97b4808a15de024f66a1ddccf",
                            "lessThan": "2c20ace1698d03a23467351be1d281e89b36ade3",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "3466abafa9f4f81a869da828e52a12f693175ec2",
                            "lessThan": "9ab0324f4868eeb20c63f063a1e5bc01d5539212",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "7fea700e04bd3f424c2d836e98425782f97b494e",
                            "lessThan": "30b274508c743f243c82904954c4e416d7143d4c",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "7fea700e04bd3f424c2d836e98425782f97b494e",
                            "lessThan": "70178691c467c8f9f722765299fd8524c3121a35",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "7fea700e04bd3f424c2d836e98425782f97b494e",
                            "lessThan": "3d15ac36ce174477efa5365e424dbd47950fd2b9",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "7fea700e04bd3f424c2d836e98425782f97b494e",
                            "lessThan": "f46cd8241d9b83f2279cc0db3e9d3e181b548a59",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "7fea700e04bd3f424c2d836e98425782f97b494e",
                            "lessThan": "5c0985dd3c32fc2bbd0e8beaf13cf52cd97376a2",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "82c7acf9a12c9b4e4b0aba531de82b4e39a345c8",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "8e69e589f233ca2c9631f5af2b94f95dfc2ba804",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "09ab5b424b17cfe633db58bb2f9edbaf9484cf20",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "6.1.95",
                            "lessThan": "6.1.191",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.35",
                            "lessThan": "6.6.161",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.10.221",
                            "lessThan": "5.11",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.15.162",
                            "lessThan": "5.16",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.9.6",
                            "lessThan": "6.10",
                            "status": "affected",
                            "versionType": "semver"
                        }
                    ]
                }

Linux

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/pid_namespace.c"
                    ],
                    "versions": [
                        {
                            "version": "6.10",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.10",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.191",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.161",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.115",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.60",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.14",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3.1",
                            "lessThanOrEqual": "7.3.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.4-rc1",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }

Original source record · Cite this exact observation · Complete original publisher JSON