{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-53187", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-06-09T07:44:35.390Z", "datePublished": "2026-06-25T08:39:00.175Z", "dateUpdated": "2026-08-05T12:33:54.299Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:33:54.299Z" }, "descriptions": [ { "lang": "en", "value": "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." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable path is reached by a local RDMA uverbs ioctl on /dev/infiniband/uverbsN, specifically RDMA_VERBS_IOCTL selecting UVERBS_METHOD_DMAH_ALLOC. It is not exposed by incoming network packets or remote RDMA traffic.\nAC:L - An attacker can supply an out-of-range UVERBS_ATTR_ALLOC_DMAH_CPU_ID directly in one ioctl, with no race or victim-controlled timing requirement. The only deployment prerequisite is an affected RDMA device exposing the DMAH uverbs method.\nPR:L - The uverbs ioctl path has no CAP_* check for DMAH allocation, and RDMA uverbs devices are designed to be usable by non-root users when the device node is accessible. This requires local low-privileged access rather than real administrator privileges.\nUI:N - No victim action is needed after the attacker has local access to the uverbs device. The attacker triggers the bug directly through the ioctl.\nS:U - The bug affects kernel RDMA/core processing within the same host kernel security authority. It does not cross a VM, IOMMU, or separate authorization boundary.\nC:H - The unchecked cpu_id is passed to cpumask_test_cpu(), which expands to test_bit() on current->cpus_ptr without a bounds check, creating an out-of-bounds kernel memory read. The result influences the returned error/path, making a kernel memory bit oracle defensible.\nI:N - The identified primitive is an out-of-bounds read of a cpumask bitmap and no kernel out-of-bounds write or control-flow corruption was found on the traced path. Passing the value onward only affects TPH steering-tag allocation if the read happens to pass.\nA:H - Large invalid cpu_id values can trigger CONFIG_DEBUG_PER_CPU_MAPS WARN_ON_ONCE(), and with panic_on_warn this reboots the machine. The same unchecked test_bit() can also fault from an out-of-bounds kernel read, making kernel oops/panic availability impact defensible." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/infiniband/core/uverbs_std_types_dmah.c" ], "versions": [ { "version": "d83edab562a496a42720902a1d2effccd05c37c5", "lessThan": "bd5e818be7964c1689fba2dad9e6bd3a827fee74", "status": "affected", "versionType": "git" }, { "version": "d83edab562a496a42720902a1d2effccd05c37c5", "lessThan": "0efbb6b54ff56300867027d8e0800d0e32226a20", "status": "affected", "versionType": "git" }, { "version": "d83edab562a496a42720902a1d2effccd05c37c5", "lessThan": "323c98a4ff06aa28114f2bf658fb43eb3b536bbc", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/infiniband/core/uverbs_std_types_dmah.c" ], "versions": [ { "version": "6.17", "status": "affected" }, { "version": "0", "lessThan": "6.17", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.36", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.13", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17", "versionEndExcluding": "6.18.36" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17", "versionEndExcluding": "7.0.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17", "versionEndExcluding": "7.1" } ] } ] } ], "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" } ], "title": "RDMA/core: Validate cpu_id against nr_cpu_ids in DMAH alloc", "x_generator": { "engine": "bippy-1.2.0" } } } }