CVE-2026-43385

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

net: Fix rcu_tasks stall in threaded busypoll

I was debugging a NIC driver when I noticed that when I enable

threaded busypoll, bpftrace hangs when starting up. dmesg showed:

rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 10658 jiffies old.

rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 40793 jiffies old.

rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 131273 jiffies old.

rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 402058 jiffies old.

INFO: rcu_tasks detected stalls on tasks:

00000000769f52cd: .N nvcsw: 2/2 holdout: 1 idle_cpu: -1/64

task:napi/eth2-8265 state:R running task stack:0 pid:48300 tgid:48300 ppid:2 task_flags:0x208040 flags:0x00004000

Call Trace:

<TASK>

? napi_threaded_poll_loop+0x27c/0x2c0

? __pfx_napi_threaded_poll+0x10/0x10

? napi_threaded_poll+0x26/0x80

? kthread+0xfa/0x2

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References