{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-35880", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-17T13:50:33.111Z", "datePublished": "2024-05-19T08:34:37.262Z", "dateUpdated": "2026-08-05T11:30:38.073Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:30:38.073Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/kbuf: hold io_buffer_list reference over mmap\n\nIf we look up the kbuf, ensure that it doesn't get unregistered until\nafter we're done with it. Since we're inside mmap, we cannot safely use\nthe io_uring lock. Rely on the fact that we can lookup the buffer list\nunder RCU now and grab a reference to it, preventing it from being\nunregistered until we're done with it. The lookup returns the\nio_buffer_list directly with it referenced." } ], "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 vulnerable path is entered only through local syscalls on an io_uring file descriptor — `mmap()` with `IORING_OFF_PBUF_RING` racing `io_uring_register(IORING_UNREGISTER_PBUF_RING)`. There is no network, adjacent, or remote-peer path into `io_uring_validate_mmap_request()`.\nAC:L - The attacker owns both sides of the race: one thread loops `mmap()` on the provided-buffer-ring offset while a second thread loops register/unregister of the same bgid on the same fd, with unlimited retries and no dependence on any condition outside the attacker's control.\nPR:L - Only an unprivileged local account is required — `io_uring_allowed()` permits any user when `sysctl_io_uring_disabled` is 0, which is the kernel default, and `IORING_REGISTER_PBUF_RING` with `IOU_PBUF_RING_MMAP` carries no capability check. This is reachable from inside containers and sandboxes as well.\nUI:N - The attacker performs every step itself — creating the ring, registering the buffer ring, and driving both racing threads. No victim action or interaction with any other user is needed.\nS:U - The defect and its consequences are confined to kernel memory within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - Without the reference, mmap consumes a `bl->buf_ring` address belonging to a buffer list being concurrently destroyed, and `remap_pfn_range()` installs a persistent `VM_PFNMAP` window onto kernel-allocated ring memory that has already been released back to the context's reusable region pool and can be re-handed to a different buffer group — an uncontrolled read of kernel memory, and per use-after-free scoring this is High.\nI:H - The resulting mapping is a writable `MAP_SHARED` view of that stale kernel region, so the attacker can write into memory the kernel no longer treats as belonging to the mapping's owner; use-after-free of a refcounted object also enables heap grooming toward a controlled-write primitive.\nA:H - Racing the teardown lets mmap operate on a `buf_ring` pointer being NULLed and on an `io_buffer_list` on its way to `kfree_rcu()`, producing oops/kernel panic; the race is repeatable at will by any local user, so availability loss is complete." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "io_uring/io_uring.c", "io_uring/kbuf.c", "io_uring/kbuf.h" ], "versions": [ { "version": "09f7520048eaaee9709091cd2787966f807da7c5", "lessThan": "65938e81df2197203bda4b9a0c477e7987218d66", "status": "affected", "versionType": "git" }, { "version": "5cf4f52e6d8aa2d3b7728f568abbf9d42a3af252", "lessThan": "5fd8e2359498043e0b5329a05f02d10a9eb91eb9", "status": "affected", "versionType": "git" }, { "version": "5cf4f52e6d8aa2d3b7728f568abbf9d42a3af252", "lessThan": "561e4f9451d65fc2f7eef564e0064373e3019793", "status": "affected", "versionType": "git" }, { "version": "6.6.5", "lessThan": "6.6.26", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "io_uring/io_uring.c", "io_uring/kbuf.c", "io_uring/kbuf.h" ], "versions": [ { "version": "6.7", "status": "affected" }, { "version": "0", "lessThan": "6.7", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.26", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.8.5", "lessThanOrEqual": "6.8.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.9", "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": "6.6.5", "versionEndExcluding": "6.6.26" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.8.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.9" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/65938e81df2197203bda4b9a0c477e7987218d66" }, { "url": "https://git.kernel.org/stable/c/5fd8e2359498043e0b5329a05f02d10a9eb91eb9" }, { "url": "https://git.kernel.org/stable/c/561e4f9451d65fc2f7eef564e0064373e3019793" } ], "title": "io_uring/kbuf: hold io_buffer_list reference over mmap", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "affected": [ { "vendor": "linux", "product": "linux_kernel", "cpes": [ "cpe:2.3:o:linux:linux_kernel:6.7:-:*:*:*:*:*:*" ], "defaultStatus": "affected", "versions": [ { "version": "6.7", "status": "affected" } ] }, { "vendor": "linux", "product": "linux_kernel", "cpes": [ "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*" ], "defaultStatus": "affected", "versions": [ { "version": "09f7520048ea", "status": "affected", "lessThan": "65938e81df21", "versionType": "git" }, { "version": "5cf4f52e6d8a", "status": "affected", "lessThan": "5fd8e2359498", "versionType": "git" }, { "version": "5cf4f52e6d8a", "status": "affected", "lessThan": "561e4f9451d6", "versionType": "git" } ] } ], "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2024-08-01T03:55:54.843818Z", "id": "CVE-2024-35880", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-08-01T13:23:38.879Z" } }, { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-02T03:21:48.591Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/65938e81df2197203bda4b9a0c477e7987218d66", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/5fd8e2359498043e0b5329a05f02d10a9eb91eb9", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/561e4f9451d65fc2f7eef564e0064373e3019793", "tags": [ "x_transferred" ] } ] } ] } }