{"cve":"CVE-2026-90342","nvd":{"published":"2026-09-17T17:17:32.877","modified":"2026-10-19T09:19:28.250","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix mmap_lock deadlock on arena lock failure\n\nReported by the Sashiko AI review.\n\narena_vm_fault() returns VM_FAULT_RETRY when it can't take\narena->spinlock, but it never took mmap_lock. The fault path assumes a\nVM_FAULT_RETRY handler already dropped mmap_lock and re-takes it on the\nretry, so mmap_lock gets taken twice and can deadlock:\n\n\tdo_user_addr_fault()\n\t{\n\t\tfault = handle_mm_fault(...);   // calls arena_vm_fault()\n\t\tif (fault & VM_FAULT_RETRY)\n\t\t\tgoto retry;   // re-locks mmap_lock\n\t\tmmap_read_unlock(mm);\n\t}\n\nReturn VM_FAULT_SIGBUS instead, for two reasons:\n\n1. We could keep VM_FAULT_RETRY, but then we'd have to drop the fault\n   lock first and cap the retry ourselves, the way __folio_lock_or_retry()\n   does.\n\n2. A failed raw_res_spin_lock_irqsave() already means a possible deadlock\n   was detected, so retrying just hits the same lock again.\n\nSo returning VM_FAULT_RETRY here is overkill.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/0b10b945479c954393d62ee3229d2f224a4ca91c","https://git.kernel.org/stable/c/af8087f16714f7620c4db3e732baaa1b2337948f"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:55:23.253742848+00:00"},"epss":{"cve":"CVE-2026-90342","score":0.00198,"percentile":0.09409,"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."]}