{"id":"CVE-2026-43401","title":"cpufreq: intel_pstate: Fix NULL pointer dereference in update_cpu_qos_request()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ncpufreq: intel_pstate: Fix NULL pointer dereference in update_cpu_qos_request()\n\nThe update_cpu_qos_request() function attempts to initialize the 'freq'\nvariable by der…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= ae1bdd23b99f64335c69d546bff99ca39b894c18 < 6bfda7ce56e7d14a677b7bcd6c7a5009cc29aa88","Linux >= ae1bdd23b99f64335c69d546bff99ca39b894c18 < 42738dffb7b0766a45882dff7989401d78f66f92","Linux >= ae1bdd23b99f64335c69d546bff99ca39b894c18 < ab39cc4cb8ceecdc2b61747433e7237f1ac2b789","Linux 6.18"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T15:37:22.098518Z"},"published":"2026-05-08","updated":"2026-11-06","sourceUpdated":"2026-11-06T15:42:51.950Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-43401","references":[{"url":"https://git.kernel.org/stable/c/6bfda7ce56e7d14a677b7bcd6c7a5009cc29aa88"},{"url":"https://git.kernel.org/stable/c/42738dffb7b0766a45882dff7989401d78f66f92"},{"url":"https://git.kernel.org/stable/c/ab39cc4cb8ceecdc2b61747433e7237f1ac2b789"}],"tags":["cve.org"],"epss":0.00121,"epssPercentile":0.01903,"ingestedAt":"2026-11-06T15:54:03.925Z","slug":"CVE-2026-43401","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ncpufreq: intel_pstate: Fix NULL pointer dereference in update_cpu_qos_request()\n\nThe update_cpu_qos_request() function attempts to initialize the 'freq'\nvariable by dereferencing 'cpudata' before verifying if the 'policy'\nis valid.\n\nThis issue occurs on systems booted with the \"nosmt\" parameter, where\nall_cpu_data[cpu] is NULL for the SMT sibling threads. As a result,\nany call to update_qos_requests() will result in a NULL pointer\ndereference as the code will attempt to access pstate.turbo_freq using\nthe NULL cpudata pointer.\n\nAlso, pstate.turbo_freq may be updated by intel_pstate_get_hwp_cap()\nafter initializing the 'freq' variable, so it is better to defer the\n'freq' until intel_pstate_get_hwp_cap() has been called.\n\nFix this by deferring the 'freq' assignment until after the policy and\ndriver_data have been validated.\n\n[ rjw: Added one paragraph to the changelog ]\n\n## Affected\n\n- `Linux >= ae1bdd23b99f64335c69d546bff99ca39b894c18 < 6bfda7ce56e7d14a677b7bcd6c7a5009cc29aa88`\n- `Linux >= ae1bdd23b99f64335c69d546bff99ca39b894c18 < 42738dffb7b0766a45882dff7989401d78f66f92`\n- `Linux >= ae1bdd23b99f64335c69d546bff99ca39b894c18 < ab39cc4cb8ceecdc2b61747433e7237f1ac2b789`\n- `Linux 6.18`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}