{"id":"CVE-2026-53187","title":"RDMA/core: Validate cpu_id against nr_cpu_ids in DMAH alloc","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/core: Validate cpu_id against nr_cpu_ids in DMAH alloc\n\nThe cpu_id attribute supplied by user space through\nUVERBS_ATTR_ALLOC_DMAH_CPU_ID is passed directly to cpu…","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= d83edab562a496a42720902a1d2effccd05c37c5 < bd5e818be7964c1689fba2dad9e6bd3a827fee74","Linux >= d83edab562a496a42720902a1d2effccd05c37c5 < 0efbb6b54ff56300867027d8e0800d0e32226a20","Linux >= d83edab562a496a42720902a1d2effccd05c37c5 < 323c98a4ff06aa28114f2bf658fb43eb3b536bbc","Linux 6.17"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-16T15:26:25.299167Z"},"published":"2026-06-25","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:31:35.708Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-53187","references":[{"url":"https://git.kernel.org/stable/c/bd5e818be7964c1689fba2dad9e6bd3a827fee74"},{"url":"https://git.kernel.org/stable/c/0efbb6b54ff56300867027d8e0800d0e32226a20"},{"url":"https://git.kernel.org/stable/c/323c98a4ff06aa28114f2bf658fb43eb3b536bbc"}],"tags":["cve.org"],"epss":0.00124,"epssPercentile":0.01909,"ingestedAt":"2026-10-16T17:24:46.734Z","slug":"CVE-2026-53187","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/core: Validate cpu_id against nr_cpu_ids in DMAH alloc\n\nThe cpu_id attribute supplied by user space through\nUVERBS_ATTR_ALLOC_DMAH_CPU_ID is passed directly to cpumask_test_cpu()\nwithout first verifying that the value is within the valid CPU range.\n\nPassing such untrusted data to cpumask_test_cpu() may lead to an\nout-of-bounds read of the underlying cpumask bitmap: the helper expands\nto a test_bit() that indexes the bitmap by cpu_id / BITS_PER_LONG with\nno bound check.\n\nIn addition, on kernels built with CONFIG_DEBUG_PER_CPU_MAPS it trips\nthe WARN_ON_ONCE() in cpumask_check(); combined with panic_on_warn this\nturns a bad user input into a machine reboot.\n\nReject any cpu_id that is not smaller than nr_cpu_ids with -EINVAL\nbefore it is used.\n\nReported by Smatch.\n\n## Affected\n\n- `Linux >= d83edab562a496a42720902a1d2effccd05c37c5 < bd5e818be7964c1689fba2dad9e6bd3a827fee74`\n- `Linux >= d83edab562a496a42720902a1d2effccd05c37c5 < 0efbb6b54ff56300867027d8e0800d0e32226a20`\n- `Linux >= d83edab562a496a42720902a1d2effccd05c37c5 < 323c98a4ff06aa28114f2bf658fb43eb3b536bbc`\n- `Linux 6.17`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}