GHSA-MGG4-G6PH-QF96
Vulnerability from github – Published: 2026-11-03 12:31 – Updated: 2026-11-03 12:31In the Linux kernel, the following vulnerability has been resolved:
pid_namespace: make zap_pid_ns_processes() freezable
When the init of a pid namespace exits, zap_pid_ns_processes() waits until all other pids in the namespace are freed. A tracer outside the namespace that does not reap its traced zombies keeps those pids allocated, so this wait has no upper bound, and while it lasts every suspend attempt fails:
Freezing user space processes failed after 20.006 seconds (2 tasks refusing to freeze, wq_busy=0):
Neither wait is freezable. The first loop sleeps in do_wait(), which returns -ERESTARTSYS on the freezer's fake signal; the loop then clears TIF_SIGPENDING and waits again without ever freezing. The final loop sleeps in TASK_INTERRUPTIBLE, and since nothing clears TIF_SIGPENDING there, schedule() returns immediately after the first freeze attempt and the task spins until the wait ends.
Sleep in TASK_INTERRUPTIBLE | TASK_FREEZABLE in do_wait(), so that the freezer can freeze tasks waiting there directly, and in TASK_IDLE | TASK_FREEZABLE in the final loop, like coredump_task_exit() does.
This was hit with Chromium-based browsers: crashpad ptrace-attaches the threads of a crashed renderer, which is a pid namespace init, and does not reap those killed during the dump.
{
"affected": [],
"aliases": [
"CVE-2026-99249"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-11-03T12:17:31Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\npid_namespace: make zap_pid_ns_processes() freezable\n\nWhen the init of a pid namespace exits, zap_pid_ns_processes() waits\nuntil all other pids in the namespace are freed. A tracer outside the\nnamespace that does not reap its traced zombies keeps those pids\nallocated, so this wait has no upper bound, and while it lasts every\nsuspend attempt fails:\n\n Freezing user space processes failed after 20.006 seconds (2 tasks refusing to freeze, wq_busy=0):\n\nNeither wait is freezable. The first loop sleeps in do_wait(), which\nreturns -ERESTARTSYS on the freezer\u0027s fake signal; the loop then clears\nTIF_SIGPENDING and waits again without ever freezing. The final loop\nsleeps in TASK_INTERRUPTIBLE, and since nothing clears TIF_SIGPENDING\nthere, schedule() returns immediately after the first freeze attempt\nand the task spins until the wait ends.\n\nSleep in TASK_INTERRUPTIBLE | TASK_FREEZABLE in do_wait(), so that the\nfreezer can freeze tasks waiting there directly, and in TASK_IDLE |\nTASK_FREEZABLE in the final loop, like coredump_task_exit() does.\n\nThis was hit with Chromium-based browsers: crashpad ptrace-attaches the\nthreads of a crashed renderer, which is a pid namespace init, and does\nnot reap those killed during the dump.",
"id": "GHSA-mgg4-g6ph-qf96",
"modified": "2026-11-03T12:31:50Z",
"published": "2026-11-03T12:31:50Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-99249"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/064a6761d6f6ac55d090d3eaca649577ee736713"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2e10b8a74f55b5aae33db105d3e2d3ae759c865a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4b47107f1a80c809c80093e872bcaccdbae13db4"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7deb5770840339fe88755bf27b92f74edc26ee87"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/81933038f5e273d17ed22792f906889393b204c5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e8dafad7de9ede813af2d48cc04b7c88fef16682"
}
],
"schema_version": "1.4.0",
"severity": []
}
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