{"id":"CVE-2026-53187","summary":"RDMA/core: Validate cpu_id against nr_cpu_ids in DMAH alloc","details":"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 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.","modified":"2026-07-08T08:07:23.668171894Z","published":"2026-06-25T08:39:00.175Z","related":["CGA-8f37-36hp-5mpx"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53187.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0efbb6b54ff56300867027d8e0800d0e32226a20"},{"type":"WEB","url":"https://git.kernel.org/stable/c/323c98a4ff06aa28114f2bf658fb43eb3b536bbc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bd5e818be7964c1689fba2dad9e6bd3a827fee74"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53187.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53187"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"d83edab562a496a42720902a1d2effccd05c37c5"},{"fixed":"bd5e818be7964c1689fba2dad9e6bd3a827fee74"},{"fixed":"0efbb6b54ff56300867027d8e0800d0e32226a20"},{"fixed":"323c98a4ff06aa28114f2bf658fb43eb3b536bbc"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53187.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.17.0"},{"fixed":"6.18.36"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.13"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53187.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H"}]}