{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "2f9469484a3b52c66b799de73bd1ca75617bc8d5"
            },
            {
              "fixed": "1a26541b3f60ce447433a4c4dd56edb10d2cd580"
            },
            {
              "fixed": "44b702fceb4cf3a4ddbfb496f487b034814bf1a3"
            },
            {
              "fixed": "cc3e12330599f097f0e1f792435686ddc276f26d"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.11.0"
            },
            {
              "fixed": "6.12.110"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "7.2.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90211.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf, s390: Clear fetch destination on faulting arena atomic\n\nSame missing register clear as on riscv64. A RMW atomic on an arena pointer\nis converted to BPF_PROBE_ATOMIC and gets an exception table entry, but\nbpf_jit_probe_atomic_pre() only fills in the arena base and the probe\noffset, leaving probe-\u003ereg at the -1 that bpf_jit_probe_init() set, which\nbpf_jit_probe_post() writes into the entry and ex_handler_bpf() then reads\nback as \"there is nothing to clear\".\n\nThat is right for a plain BPF_{ADD,AND,OR,XOR}, which only writes memory,\nbut an RMW carrying BPF_FETCH also reads the old value into a register:\nsrc_reg for BPF_{ADD,AND,OR,XOR} | BPF_FETCH and BPF_XCHG, and r0 for\nBPF_CMPXCHG. So on a fault over an unmapped arena page the program resumes\nat the landing pad with whatever that register held before the atomic\ninstead of the 0 that every other BPF_PROBE_* access delivers.\n\nFill probe-\u003ereg in from bpf_atomic_load_reg(). Unlike x86-64 and arm64,\ns390x does not report arena violations from its exception handler, so there\nis no access direction to correct here, only the missing register clear.",
  "id": "CVE-2026-90211",
  "modified": "2026-09-19T03:30:17.643099388Z",
  "published": "2026-09-17T16:07:25.454Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1a26541b3f60ce447433a4c4dd56edb10d2cd580"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/44b702fceb4cf3a4ddbfb496f487b034814bf1a3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cc3e12330599f097f0e1f792435686ddc276f26d"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90211.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90211"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "bpf, s390: Clear fetch destination on faulting arena atomic"
}