In the Linux kernel, the following vulnerability has been resolved:
mm/kmemleak: avoid soft lockup in __kmemleak_do_cleanup()
A soft lockup warning was observed on a relative small system x86-64 system with 16 GB of memory when running a debug kernel with kmemleak enabled.
watchdog: BUG: soft lockup - CPU#8 stuck for 33s! [kworker/8:1:134]
The test system was running a workload with hot unplug happening in parallel. Then kemleak decided to disable itself due to its inability to allocate more kmemleak objects. The debug kernel has its CONFIG_DEBUG_KMEMLEAK_MEM_POOL_SIZE set to 40,000.
The soft lockup happened in kmemleak_do_cleanup() when the existing kmemleak objects were being removed and deleted one-by-one in a loop via a workqueue. In this particular case, there are at least 40,000 objects that need to be processed and given the slowness of a debug kernel and the fact that a raw_spinlock has to be acquired and released in __delete_object(), it could take a while to properly handle all these objects.
As kmemleak has been disabled in this case, the object removal and deletion process can be further optimized as locking isn't really needed. However, it is probably not worth the effort to optimize for such an edge case that should rarely happen. So the simple solution is to call cond_resched() at periodic interval in the iteration loop to avoid soft lockup.
| Software | From | Fixed in |
|---|---|---|
| linux / linux_kernel | 5.4.1 | 5.4.297 |
| linux / linux_kernel | 5.5 | 5.10.241 |
| linux / linux_kernel | 5.11 | 5.15.190 |
| linux / linux_kernel | 5.16 | 6.1.149 |
| linux / linux_kernel | 6.2 | 6.6.103 |
| linux / linux_kernel | 6.7 | 6.12.43 |
| linux / linux_kernel | 6.13 | 6.15.11 |
| linux / linux_kernel | 6.16 | 6.16.2 |
| linux / linux_kernel | 5.4 | 5.4.x |
| linux / linux_kernel | 5.4-rc4 | 5.4-rc4.x |
| linux / linux_kernel | 5.4-rc5 | 5.4-rc5.x |
| linux / linux_kernel | 5.4-rc6 | 5.4-rc6.x |
| linux / linux_kernel | 5.4-rc7 | 5.4-rc7.x |
| linux / linux_kernel | 5.4-rc8 | 5.4-rc8.x |
| linux / linux_kernel | 6.17-rc1 | 6.17-rc1.x |
| debian / debian_linux | 11.0 | 11.0.x |
A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.
Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.