{"id":"CVE-2026-89509","title":"RDMA/ionic: Embed counter driver data in rdma_counter allocation","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/ionic: Embed counter driver data in rdma_counter allocation\n\nCommit 7e53b31acc7f (\"RDMA/core: Create and destroy rdma_counter using\nrdma_zalloc_drv_obj()\") require…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":["CWE-476"],"vendor":"Linux","product":"Linux","affected":["Linux >= ea4c399642b85dc30f44d90ee805c6a18fa03062 < c98197ee3cd28288da13dc9881bb9e74daa7cbbc","Linux >= ea4c399642b85dc30f44d90ee805c6a18fa03062 < 08b8630b557828aedb1d9ef0a6e2ec421f334ee2","Linux >= ea4c399642b85dc30f44d90ee805c6a18fa03062 < cf3ebd89e754015625fee90aa938f6bc79a2c974","Linux 6.18"],"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:48:00.667Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89509","references":[{"url":"https://git.kernel.org/stable/c/c98197ee3cd28288da13dc9881bb9e74daa7cbbc"},{"url":"https://git.kernel.org/stable/c/08b8630b557828aedb1d9ef0a6e2ec421f334ee2"},{"url":"https://git.kernel.org/stable/c/cf3ebd89e754015625fee90aa938f6bc79a2c974"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89509.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89509"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532215"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89509"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89509"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89509.mbox"}],"tags":["cve.org","csaf","vex","red-hat"],"epss":0.00206,"epssPercentile":0.10622,"ingestedAt":"2026-09-14T11:11:19.887Z","slug":"CVE-2026-89509","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/ionic: Embed counter driver data in rdma_counter allocation\n\nCommit 7e53b31acc7f (\"RDMA/core: Create and destroy rdma_counter using\nrdma_zalloc_drv_obj()\") requires drivers implementing counter ops to\nembed struct rdma_counter in a driver-specific struct, register its size\nvia INIT_RDMA_OBJ_SIZE, and provide a counter_init callback.\n\nThe ionic driver was merged without this adaptation, causing a NULL\npointer dereference in alloc_and_bind() since rdma_zalloc_drv_obj()\nallocates zero bytes when size_rdma_counter is unset.\n\nConsolidate struct ionic_counter into a new struct ionic_rdma_counter\nthat embeds struct rdma_counter, replace the xarray with a lightweight\nida for ID allocation, and add the required counter_init and\nINIT_RDMA_OBJ_SIZE declarations.\n\n## Affected\n\n- `Linux >= ea4c399642b85dc30f44d90ee805c6a18fa03062 < c98197ee3cd28288da13dc9881bb9e74daa7cbbc`\n- `Linux >= ea4c399642b85dc30f44d90ee805c6a18fa03062 < 08b8630b557828aedb1d9ef0a6e2ec421f334ee2`\n- `Linux >= ea4c399642b85dc30f44d90ee805c6a18fa03062 < cf3ebd89e754015625fee90aa938f6bc79a2c974`\n- `Linux 6.18`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89509.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":206939,"id":"CVE-2026-89509","ts":1789749709440,"field":"cvss","old":"4.1","new":"5.5"},{"seq":204073,"id":"CVE-2026-89509","ts":1789490231314,"field":"cvss","old":null,"new":"4.1"},{"seq":204072,"id":"CVE-2026-89509","ts":1789490231314,"field":"severity","old":"none","new":"medium"},{"seq":147590,"id":"CVE-2026-89509","ts":1789270211508,"field":"cvss","old":null,"new":"4.1"},{"seq":147589,"id":"CVE-2026-89509","ts":1789270211508,"field":"severity","old":"none","new":"medium"},{"seq":109350,"id":"CVE-2026-89509","ts":1789183731567,"field":"cvss","old":null,"new":"4.1"},{"seq":109349,"id":"CVE-2026-89509","ts":1789183731567,"field":"severity","old":"none","new":"medium"}]}