{"cve":"CVE-2026-64017","nvd":{"published":"2026-07-19T16:17:41.680","modified":"2026-10-19T21:17:19.333","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nblk-mq: pop cached request if it is usable\n\nWhen submitting a bio to blk-mq, if the task should sleep after peeking\na cached request, but before it pops it, the plug flushes and calls\nblk_mq_free_plug_rqs, freeing the cached_rqs. This creates a\nuse-after-free bug. Fix this by popping the cached request before any\npossible blocking calls if it is suitable for use.\n\nPopping this request first holds a queue reference, so avoid any\nserialization races with queue freezes and can safely proceed with\ndispatching that request to the driver. This potentially increases a\ntiming window from when a driver wants to freeze its queue to when\nrequests stop being dispatched. That scenario is off the fast path\nthough, and drivers need to appropriately handle requests during a\nfreeze request anyway.\n\nThe downside is the popped element needs to be individually freed when\nwe performed a bio plug merge. The cached request would have had to be\nfreed later anyway, but this patch does it inline with building the plug\nlist instead of after flushing it.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/23d8ea1e303b5f32d883757a4a707e791dbc9808","https://git.kernel.org/stable/c/388468f7e7d1eab092cf2a39fdfb502e52019ec6","https://git.kernel.org/stable/c/97e2d08de282ef76f84ab4ccd00f1acb3f5f999e","https://git.kernel.org/stable/c/dc278e9bf2b9513a763353e6b9cc21e0f532954e"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2026-64017","score":0.00125,"percentile":0.02226,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}