boxscore/security
CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2023-53531MEDIUM
Linux Linux — null_blk: fix poll request timeout handling
  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   L   L   N  U  N  N  H    5.5   .0014    3.9     —
AFFECTED
  Product  Versions                                    Fixed
  Linux    0a593fbbc245a85940ed34caa3aa1e4cb060c54b –  —
  Linux    5.16 –                                      6.1.54
TIMELINE
  Oct 1   Reserved by Linux
  Oct 1   Published (CNA: Linux)
  Aug 4   RESCORED — CVE-2023-53531 (Linux). CVSS 7.8 → 5.5 (NVD).
CWE-476 · CNA: Linux · CVSS v3.1 · 3 references · NVD status: Modified

Description

In the Linux kernel, the following vulnerability has been resolved: null_blk: fix poll request timeout handling When doing io_uring benchmark on /dev/nullb0, it's easy to crash the kernel if poll requests timeout triggered, as reported by David. [1] BUG: kernel NULL pointer dereference, address: 0000000000000008 Workqueue: kblockd blk_mq_timeout_work RIP: 0010:null_timeout_rq+0x4e/0x91 Call Trace: ? null_timeout_rq+0x4e/0x91 blk_mq_handle_expired+0x31/0x4b bt_iter+0x68/0x84 ? bt_tags_iter+0x81/0x81 __sbitmap_for_each_set.constprop.0+0xb0/0xf2 ? __blk_mq_complete_request_remote+0xf/0xf bt_for_each+0x46/0x64 ? __blk_mq_complete_request_remote+0xf/0xf ? percpu_ref_get_many+0xc/0x2a blk_mq_queue_tag_busy_iter+0x14d/0x18e blk_mq_timeout_work+0x95/0x127 process_one_work+0x185/0x263 worker_thread+0x1b5/0x227 This is indeed a race problem between null_timeout_rq() and null_poll(). null_poll() null_timeout_rq() spin_lock(&nq->poll_lock) list_splice_init(&nq->poll_list, &list) spin_unlock(&nq->poll_lock) while (!list_empty(&list)) req = list_first_entry() list_del_init() ... blk_mq_add_to_batch() // req->rq_next = NULL spin_lock(&nq->poll_lock) // rq->queuelist->next == NULL list_del_init(&rq->queuelist) spin_unlock(&nq->poll_lock) Fix these problems by setting requests state to MQ_RQ_COMPLETE under nq->poll_lock protection, in which null_timeout_rq() can safely detect this race and early return. Note this patch just fix the kernel panic when request timeout happen. [1] https://lore.kernel.org/all/3893581.1691785261@warthog.procyon.org.uk/

Lifecycle

Complete event history — 3 events, chronological
DateEventDetail
October 1, 2025ReservedReserved by Linux
October 1, 2025PublishedPublished (CNA: Linux)
August 4, 2026RESCOREDRESCORED — CVE-2023-53531 (Linux). CVSS 7.8 → 5.5 (NVD).

Affected

Affected products and packages — 2 rows
VendorProduct / PackageEcosystemVersion introducedFixed
LinuxLinux0a593fbbc245a85940ed34caa3aa1e4cb060c54b
LinuxLinux5.166.1.54

Weaknesses

CWE-476

References (3)

Related

Authoritative record: CVE-2023-53531 at cve.org

Vendors: linux

Weaknesses: CWE-476

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2023-53531 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.