{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-89499",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-09-11T19:38:34.715Z",
        "datePublished": "2026-09-11T19:43:48.752Z",
        "dateUpdated": "2026-10-19T08:47:50.883Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-19T08:47:50.883Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nring-buffer: Stop remote reader update when page swap fails\n\nThe remote swap_reader_page callback can return -EBUSY when the writer\nmoves the head before the remote catches it, particularly during an event\nstorm on a small buffer. __rb_get_reader_page_from_remote() currently\nwarns about that failure but continues with the unchanged reader ID and\nrearranges the local page list as though the swap succeeded.\n\nHandle the callback failure as a recoverable error. Report it with\npr_warn_ratelimited() and return NULL. Callers already handle a NULL reader\npage as a failed attempt. This avoids splicing the same page as both the\nprevious and new reader without flooding the log under contention."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 7.8,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - The bug is reached only by a local read of tracefs remotes/*/trace_pipe or remotes/*/trace, which calls ring_buffer_peek/consume then rb_get_reader_page() and __rb_get_reader_page_from_remote(). No network, adjacent-radio, or physical-device path reaches this remote reader swap.\nAC:L - An attacker with tracefs access sets a small remotes/*/buffer_size_kb, enables tracing, generates an event storm via remotes/*/write_event or KVM hyp events, and reads trace_pipe. That is the documented -EBUSY case; the attacker controls writer load and the reader swap, so the failed-swap path is reliably hit.\nPR:L - remotes/ files are mode 0440/0640 and use custom fops with no capable() or tracing_check_open_get_tr() check, only DAC. tracing-gid mounts on Android eng/Perfetto, ChromeOS, and developer kernels grant this to unprivileged users, matching prior CNA tracefs scores.\nUI:N - The attacker opens, configures, and reads their own remotes/*/trace_pipe and related tracefs files. No separate victim mount, click, or other user action is required.\nS:U - The corruption is of host kernel ring-buffer buffer_page lists and reader metadata in the same OS security authority. A host-local tracefs user cannot use this as a VM/IOMMU/guest-to-host escape.\nC:H - On swap failure the kernel still splices the unchanged reader page into the list and shares it with the remote writer. Torn event headers make rb_event_length() return unbounded sizes, and later peeks follow corrupted buffer_page pointers, enabling out-of-bounds kernel reads.\nI:H - __rb_get_reader_page_from_remote() writes list.next/list.prev as if the swap succeeded, creating a self-referential reader and unlinking the real head. Subsequent swaps and rb_inc_page/rb_list_head_clear store further pointers on that corrupted topology, which is exploitable kernel metadata corruption.\nA:H - The failed-swap path hits WARN_ON_ONCE(prev_reader == new_reader), can infinite-loop walking the spliced list, and oopses on corrupted page pointers. panic_on_warn makes those WARNs a kernel panic, and the attacker can retrigger the path at will."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/trace/ring_buffer.c"
                    ],
                    "versions": [
                        {
                            "version": "2e67fabd8b77c4f482df9b211bca1b495c6c2c24",
                            "lessThan": "a14a97048e48471e283d76879b83d2ae323e0722",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "2e67fabd8b77c4f482df9b211bca1b495c6c2c24",
                            "lessThan": "5eab74874d11160725c42ab676ba97a797a362eb",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/trace/ring_buffer.c"
                    ],
                    "versions": [
                        {
                            "version": "7.1",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "7.1",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.4",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "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": "7.1",
                                    "versionEndExcluding": "7.2.4"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "7.1",
                                    "versionEndExcluding": "7.3"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/a14a97048e48471e283d76879b83d2ae323e0722"
                },
                {
                    "url": "https://git.kernel.org/stable/c/5eab74874d11160725c42ab676ba97a797a362eb"
                }
            ],
            "title": "ring-buffer: Stop remote reader update when page swap fails",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
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    }
}