{"cve":"CVE-2026-72112","nvd":{"published":"2026-08-15T06:21:25.563","modified":"2026-08-17T06:18:10.417","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/bpf-ops: reject re-registration of an already-bound ops\n\nio_install_bpf() only rejects a second registration on the ctx side\n(ctx->bpf_ops) and sets the per-map back-pointer ops->priv\nunconditionally. The struct_ops link path never advances a map past\nBPF_STRUCT_OPS_STATE_READY, so the same io_uring_bpf_ops map can be\nregistered more than once, and bpf_io_reg() re-resolves the target ring\nvia fget(ops->ring_fd) on every call. A caller can therefore point the\nsame ring_fd at a different io_ring_ctx between two BPF_LINK_CREATE\ncalls.\n\nThe second registration passes the ctx->bpf_ops check (the new ctx has\nnone) and overwrites ops->priv, orphaning the first ctx. Teardown\n(io_eject_bpf()/bpf_io_unreg()) only reaches a ctx through ops->priv, so\nthe orphaned ctx is never torn down: its ctx->loop_step keeps pointing\ninto the struct_ops trampoline, which is freed once the map is gone. A\nlater io_uring_enter() on the orphaned ring then calls the dangling\nctx->loop_step from io_run_loop() -- a use-after-free of freed\nexecutable memory, reachable by a task with CAP_BPF + CAP_PERFMON.\n\nReject registration when ops->priv is already set, as hid_bpf_reg()\ndoes for its struct_ops.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":[],"references":["https://git.kernel.org/stable/c/0639ea767fe04c288a8d6cb826100fe3d95d4936","https://git.kernel.org/stable/c/3afc64c61ce906a04f073ca350b46de10e8302f9"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:48:17.459049833+00:00"},"epss":{"cve":"CVE-2026-72112","score":0.00165,"percentile":0.05714,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}