{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-40319", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.186Z", "datePublished": "2025-12-08T00:46:46.448Z", "dateUpdated": "2026-08-05T12:09:31.491Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:09:31.491Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Sync pending IRQ work before freeing ring buffer\n\nFix a race where irq_work can be queued in bpf_ringbuf_commit()\nbut the ring buffer is freed before the work executes.\nIn the syzbot reproducer, a BPF program attached to sched_switch\ntriggers bpf_ringbuf_commit(), queuing an irq_work. If the ring buffer\nis freed before this work executes, the irq_work thread may accesses\nfreed memory.\nCalling `irq_work_sync(&rb->work)` ensures that all pending irq_work\ncomplete before freeing the buffer." } ], "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 vulnerability is reached through the `bpf()` syscall — creating a ringbuf map, loading a program that calls `bpf_ringbuf_output`/`submit`, and closing the fds to drive `ringbuf_map_free()`. There is no path for a remote peer to load BPF programs, so local system access is required.\nAC:L - The attacker controls both sides of the race: he triggers `bpf_ringbuf_commit()` on demand (loopback packet into his own socket filter, using `BPF_RB_FORCE_WAKEUP` to guarantee `irq_work_queue()` on every commit) and separately triggers the free by detaching and closing the map/prog fds, looping unboundedly. On PREEMPT_RT the work is deferred to the `irq_workd` kthread and on architectures without `arch_irq_work_has_interrupt()` to the next tick, widening the window to milliseconds; syzbot both reproduced the bug and confirmed the fix.\nPR:L - `BPF_MAP_TYPE_RINGBUF`/`USER_RINGBUF` are listed as unprivileged map types in `map_create()`, the ringbuf helpers sit above the `CAP_BPF` gate in `bpf_base_func_proto()`, `BPF_PROG_TYPE_SOCKET_FILTER` is exempt from the CAP_BPF prog-load check, and `SO_ATTACH_BPF` has no capability check — so an ordinary unprivileged user can build the entire chain on the upstream default `unprivileged_bpf_disabled=0`.\nUI:N - The attacker performs every step himself — map creation, program load, socket attach, packet injection, and fd close — with no victim action or cooperating process required.\nS:U - The use-after-free corrupts kernel memory and the per-CPU irq_work list within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - `irq_work_single()` and `bpf_ringbuf_notify()`/`wake_up_all()` read `work->node.llist`, `work->func`, `work->irqwait.task`, and the `waitq` list head out of freed memory, and the vmalloc VA range can be reclaimed with a large vmalloc-backed `BPF_MAP_TYPE_ARRAY` whose contents the attacker sets — turning the dangling traversal into an arbitrary kernel-memory read/disclosure primitive.\nI:H - The irq_work core performs `atomic_set()`/`atomic_cmpxchg()` writes into the freed object and an indirect call `work->func(work)` on a pointer read from it, while `wake_up_all()` adds `list_del_init()` unlink writes and a second function-pointer call — after VA-range reclamation with controlled data this is a direct control-flow hijack and arbitrary-write path to privilege escalation.\nA:H - This is a use-after-free reported by syzbot as a KASAN splat; in the common case the irq_work dereferences an already-unmapped vmalloc address from hardirq or the `irq_workd` kthread, producing an unhandled page fault and kernel panic, and it can be re-triggered in a loop." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/bpf/ringbuf.c" ], "versions": [ { "version": "457f44363a8894135c85b7a9afd2bd8196db24ab", "lessThan": "47626748a2a00068dbbd5836d19076637b4e235b", "status": "affected", "versionType": "git" }, { "version": "457f44363a8894135c85b7a9afd2bd8196db24ab", "lessThan": "de2ce6b14bc3e565708a39bdba3ef9162aeffc72", "status": "affected", "versionType": "git" }, { "version": "457f44363a8894135c85b7a9afd2bd8196db24ab", "lessThan": "e1828c7a8d8135e21ff6adaaa9458c32aae13b11", "status": "affected", "versionType": "git" }, { "version": "457f44363a8894135c85b7a9afd2bd8196db24ab", "lessThan": "6451141103547f4efd774e912418a3b4318046c6", "status": "affected", "versionType": "git" }, { "version": "457f44363a8894135c85b7a9afd2bd8196db24ab", "lessThan": "10ca3b2eec384628bc9f5d8190aed9427ad2dde6", "status": "affected", "versionType": "git" }, { "version": "457f44363a8894135c85b7a9afd2bd8196db24ab", "lessThan": "430e15544f11f8de26b2b5109c7152f71b78295e", "status": "affected", "versionType": "git" }, { "version": "457f44363a8894135c85b7a9afd2bd8196db24ab", "lessThan": "4e9077638301816a7d73fa1e1b4c1db4a7e3b59c", "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/bpf/ringbuf.c" ], "versions": [ { "version": "5.8", "status": "affected" }, { "version": "0", "lessThan": "5.8", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.247", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.197", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.159", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.117", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.58", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.17.8", "lessThanOrEqual": "6.17.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18", "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": "5.8", "versionEndExcluding": "5.10.247" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "5.15.197" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.1.159" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.6.117" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.12.58" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.17.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.18" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/47626748a2a00068dbbd5836d19076637b4e235b" }, { "url": "https://git.kernel.org/stable/c/de2ce6b14bc3e565708a39bdba3ef9162aeffc72" }, { "url": "https://git.kernel.org/stable/c/e1828c7a8d8135e21ff6adaaa9458c32aae13b11" }, { "url": "https://git.kernel.org/stable/c/6451141103547f4efd774e912418a3b4318046c6" }, { "url": "https://git.kernel.org/stable/c/10ca3b2eec384628bc9f5d8190aed9427ad2dde6" }, { "url": "https://git.kernel.org/stable/c/430e15544f11f8de26b2b5109c7152f71b78295e" }, { "url": "https://git.kernel.org/stable/c/4e9077638301816a7d73fa1e1b4c1db4a7e3b59c" } ], "title": "bpf: Sync pending IRQ work before freeing ring buffer", "x_generator": { "engine": "bippy-1.2.0" } } } }