In 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.
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.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Tue, 03 Nov 2026 11:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In 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. | |
| Title | pid_namespace: make zap_pid_ns_processes() freezable | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-11-03T11:18:26.800Z
Reserved: 2026-09-25T10:25:14.403Z
Link: CVE-2026-99249
Vulnrichment
No data.
NVD
No data.
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.