{"cve":"CVE-2021-47617","nvd":{"published":"2024-06-20T11:15:54.317","modified":"2026-06-17T04:18:10.317","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nPCI: pciehp: Fix infinite loop in IRQ handler upon power fault\n\nThe Power Fault Detected bit in the Slot Status register differs from\nall other hotplug events in that it is sticky:  It can only be cleared\nafter turning off slot power.  Per PCIe r5.0, sec. 6.7.1.8:\n\n  If a power controller detects a main power fault on the hot-plug slot,\n  it must automatically set its internal main power fault latch [...].\n  The main power fault latch is cleared when software turns off power to\n  the hot-plug slot.\n\nThe stickiness used to cause interrupt storms and infinite loops which\nwere fixed in 2009 by commits 5651c48cfafe (\"PCI pciehp: fix power fault\ninterrupt storm problem\") and 99f0169c17f3 (\"PCI: pciehp: enable\nsoftware notification on empty slots\").\n\nUnfortunately in 2020 the infinite loop issue was inadvertently\nreintroduced by commit 8edf5332c393 (\"PCI: pciehp: Fix MSI interrupt\nrace\"):  The hardirq handler pciehp_isr() clears the PFD bit until\npciehp's power_fault_detected flag is set.  That happens in the IRQ\nthread pciehp_ist(), which never learns of the event because the hardirq\nhandler is stuck in an infinite loop.  Fix by setting the\npower_fault_detected flag already in the hardirq handler.","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-835"],"references":["https://git.kernel.org/stable/c/1db58c6584a72102e98af2e600ea184ddaf2b8af","https://git.kernel.org/stable/c/23584c1ed3e15a6f4bfab8dc5a88d94ab929ee12","https://git.kernel.org/stable/c/3b4c966fb156ff3e70b2526d964952ff7c1574d9","https://git.kernel.org/stable/c/464da38ba827f670deac6500a1de9a4f0f44c41d","https://git.kernel.org/stable/c/6d6f1f0dac3e3441ecdb1103d4efb11b9ed24dd5"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:52:00.836172422+00:00"},"epss":{"cve":"CVE-2021-47617","score":0.0021,"percentile":0.11283,"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."]}