{"cve":"CVE-2023-52993","nvd":{"published":"2025-03-27T17:15:46.820","modified":"2026-06-17T06:44:04.497","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/i8259: Mark legacy PIC interrupts with IRQ_LEVEL\n\nBaoquan reported that after triggering a crash the subsequent crash-kernel\nfails to boot about half of the time. It triggers a NULL pointer\ndereference in the periodic tick code.\n\nThis happens because the legacy timer interrupt (IRQ0) is resent in\nsoftware which happens in soft interrupt (tasklet) context. In this context\nget_irq_regs() returns NULL which leads to the NULL pointer dereference.\n\nThe reason for the resend is a spurious APIC interrupt on the IRQ0 vector\nwhich is captured and leads to a resend when the legacy timer interrupt is\nenabled. This is wrong because the legacy PIC interrupts are level\ntriggered and therefore should never be resent in software, but nothing\never sets the IRQ_LEVEL flag on those interrupts, so the core code does not\nknow about their trigger type.\n\nEnsure that IRQ_LEVEL is set when the legacy PCI interrupts are set up.","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":["CWE-476"],"references":["https://git.kernel.org/stable/c/0b08201158f177aab469e356b4d6af24fdd118df","https://git.kernel.org/stable/c/137f1b47da5f58805da42c1b7811e28c1e353f39","https://git.kernel.org/stable/c/496975d1a2937f4baadf3d985991b13fc4fc4f27","https://git.kernel.org/stable/c/5fa55950729d0762a787451dc52862c3f850f859","https://git.kernel.org/stable/c/744fe9be9665227335539b7a77ece8d9ff62b6c0"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:00:28.034033815+00:00"},"epss":{"cve":"CVE-2023-52993","score":0.00269,"percentile":0.19182,"date":"2026-10-31"},"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."]}