Cluster on C&CZ News https://cncz.science.ru.nl/tags/cluster/ Recent content in Cluster on C&CZ News Hugo -- gohugo.io en-us postmaster Fri, 22 May 2026 00:00:00 +0200 Ptrace setting set to 2 due to kernel vulnerability https://cncz.science.ru.nl/cpk/1430/ Fri, 22 May 2026 00:00:00 +0200 Simon Oosthoek https://cncz.science.ru.nl/cpk/1430/ <p>We became aware of the <a href="https://github.com/torvalds/linux/commit/31e62c2ebbfdc3fe3dbdf5e02c92a9dc67087a3a" target="_blank">Kernel vulnerability</a> and implemented the <a href="https://fosstodon.org/@frehi/116577617410490758" target="_blank">kernel vulnerability mitigation</a></p> <p>The change was to set</p> <pre tabindex="0"><code>kernel.yama.ptrace_scope = 2 </code></pre><p>(A sysctl setting). For users of MPI jobs, this setting broke the jobs. When we have a fixed kernel and rebooted the nodes, we can change this back to something that will work with MPI.</p> <p>Workaround or fix, use <code>mpirun --mca btl_vader_single_copy_mechanism none etc...</code></p>