{"cve":"CVE-2026-23168","nvd":{"published":"2026-02-14T16:15:57.023","modified":"2026-06-17T10:21:01.640","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nflex_proportions: make fprop_new_period() hardirq safe\n\nBernd has reported a lockdep splat from flexible proportions code that is\nessentially complaining about the following race:\n\n<timer fires>\nrun_timer_softirq - we are in softirq context\n  call_timer_fn\n    writeout_period\n      fprop_new_period\n        write_seqcount_begin(&p->sequence);\n\n        <hardirq is raised>\n        ...\n        blk_mq_end_request()\n\t  blk_update_request()\n\t    ext4_end_bio()\n\t      folio_end_writeback()\n\t\t__wb_writeout_add()\n\t\t  __fprop_add_percpu_max()\n\t\t    if (unlikely(max_frac < FPROP_FRAC_BASE)) {\n\t\t      fprop_fraction_percpu()\n\t\t\tseq = read_seqcount_begin(&p->sequence);\n\t\t\t  - sees odd sequence so loops indefinitely\n\nNote that a deadlock like this is only possible if the bdi has configured\nmaximum fraction of writeout throughput which is very rare in general but\nfrequent for example for FUSE bdis.  To fix this problem we have to make\nsure write section of the sequence counter is irqsafe.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/0acc9ba7a1b5ba4d998c5753e709be904e179b75","https://git.kernel.org/stable/c/78ede9ebd679dadf480dce6f7b798e3603f88348","https://git.kernel.org/stable/c/884b2590ffcc7222cbbd6298051f4c243cc36f5d","https://git.kernel.org/stable/c/b91a84299d72ae0e05551e851e47cd3008bd025b","https://git.kernel.org/stable/c/dd9e2f5b38f1fdd49b1ab6d3a85f81c14369eacc"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:23:35.260773158+00:00"},"epss":{"cve":"CVE-2026-23168","score":0.00134,"percentile":0.02861,"date":"2026-11-01"},"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."]}