{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-52903", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-08-21T06:07:11.014Z", "datePublished": "2024-08-21T06:10:43.857Z", "dateUpdated": "2026-08-05T09:11:53.830Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:11:53.830Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring: lock overflowing for IOPOLL\n\nsyzbot reports an issue with overflow filling for IOPOLL:\n\nWARNING: CPU: 0 PID: 28 at io_uring/io_uring.c:734 io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734\nCPU: 0 PID: 28 Comm: kworker/u4:1 Not tainted 6.2.0-rc3-syzkaller-16369-g358a161a6a9e #0\nWorkqueue: events_unbound io_ring_exit_work\nCall trace:\n io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734\n io_req_cqe_overflow+0x5c/0x70 io_uring/io_uring.c:773\n io_fill_cqe_req io_uring/io_uring.h:168 [inline]\n io_do_iopoll+0x474/0x62c io_uring/rw.c:1065\n io_iopoll_try_reap_events+0x6c/0x108 io_uring/io_uring.c:1513\n io_uring_try_cancel_requests+0x13c/0x258 io_uring/io_uring.c:3056\n io_ring_exit_work+0xec/0x390 io_uring/io_uring.c:2869\n process_one_work+0x2d8/0x504 kernel/workqueue.c:2289\n worker_thread+0x340/0x610 kernel/workqueue.c:2436\n kthread+0x12c/0x158 kernel/kthread.c:376\n ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:863\n\nThere is no real problem for normal IOPOLL as flush is also called with\nuring_lock taken, but it's getting more complicated for IOPOLL|SQPOLL,\nfor which __io_cqring_overflow_flush() happens from the CQ waiting path." } ], "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 in io_uring IOPOLL completion overflow (`io_do_iopoll` → `io_fill_cqe_req` → `io_req_cqe_overflow`), reachable only via local `io_uring_setup`/`io_uring_enter` on an attacker-owned ring, not via network packet processing.\nAC:L - An attacker can force CQ overflow on an IOPOLL ring while concurrently posting aux CQEs (e.g. `IORING_MSG_DATA` via msg_ring’s `io_post_aux_cqe`, which took only `completion_lock`) so both sides of the `cq_overflow_list` race are attacker-controlled.\nPR:L - io_uring is usable by unprivileged local users by default (`kernel.io_uring_disabled=0`); IOPOLL and msg_ring require no CAP_SYS_ADMIN or init-namespace root.\nUI:N - The attacker creates the ring(s), submits IOPOLL work, overflows the CQ, and drives concurrent overflow/aux posting themselves; no victim action is required.\nS:U - Impact is kernel memory corruption within the host OS authority (local privilege escalation); no VM escape, IOMMU bypass, or sandbox boundary is crossed.\nC:H - Missing `completion_lock` while mutating `cq_overflow_list` races with other overflow/aux posters holding that lock, enabling linked-list corruption and use-after-free of overflow entries that can be leveraged for arbitrary kernel memory disclosure.\nI:H - Concurrent unlocked list add/delete/kfree on `cq_overflow_list` yields classic heap UAF/double-free primitives exploitable for arbitrary write and control-flow hijacking.\nA:H - The same race can oops/panic the kernel via list corruption, and the observed lockdep path is a `WARN` in `io_cqring_event_overflow` (High under panic_on_warn / oops deployments)." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "io_uring/rw.c" ], "versions": [ { "version": "2b188cc1bb857a9d4701ae59aa7768b5124e262e", "lessThan": "de77faee280163ff03b7ab64af6c9d779a43d4c4", "status": "affected", "versionType": "git" }, { "version": "2b188cc1bb857a9d4701ae59aa7768b5124e262e", "lessThan": "ed4629d1e968359fbb91d0a3780b1e86a2c08845", "status": "affected", "versionType": "git" }, { "version": "2b188cc1bb857a9d4701ae59aa7768b5124e262e", "lessThan": "7fc3990dad04a677606337ebc61964094d6cb41b", "status": "affected", "versionType": "git" }, { "version": "2b188cc1bb857a9d4701ae59aa7768b5124e262e", "lessThan": "544d163d659d45a206d8929370d5a2984e546cb7", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "io_uring/rw.c" ], "versions": [ { "version": "5.1", "status": "affected" }, { "version": "0", "lessThan": "5.1", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.165", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.89", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.7", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.2", "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": "5.1", "versionEndExcluding": "5.10.165" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "5.15.89" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.1.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/de77faee280163ff03b7ab64af6c9d779a43d4c4" }, { "url": "https://git.kernel.org/stable/c/ed4629d1e968359fbb91d0a3780b1e86a2c08845" }, { "url": "https://git.kernel.org/stable/c/7fc3990dad04a677606337ebc61964094d6cb41b" }, { "url": "https://git.kernel.org/stable/c/544d163d659d45a206d8929370d5a2984e546cb7" } ], "title": "io_uring: lock overflowing for IOPOLL", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2023-52903", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-09-10T16:03:21.069603Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-09-12T17:33:14.061Z" } } ] } }