{"cve":"CVE-2021-47327","nvd":{"published":"2024-05-21T15:15:19.757","modified":"2026-06-17T04:17:12.227","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu/arm-smmu: Fix arm_smmu_device refcount leak when arm_smmu_rpm_get fails\n\narm_smmu_rpm_get() invokes pm_runtime_get_sync(), which increases the\nrefcount of the \"smmu\" even though the return value is less than 0.\n\nThe reference counting issue happens in some error handling paths of\narm_smmu_rpm_get() in its caller functions. When arm_smmu_rpm_get()\nfails, the caller functions forget to decrease the refcount of \"smmu\"\nincreased by arm_smmu_rpm_get(), causing a refcount leak.\n\nFix this issue by calling pm_runtime_resume_and_get() instead of\npm_runtime_get_sync() in arm_smmu_rpm_get(), which can keep the refcount\nbalanced in case of failure.","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:N/A:H","score":7.1},"cwes":["CWE-911"],"references":["https://git.kernel.org/stable/c/1adf30f198c26539a62d761e45af72cde570413d","https://git.kernel.org/stable/c/3761ae0d0e549f2acdaf11f49df4ed06d256b20f","https://git.kernel.org/stable/c/c4007596fbdabc29f858dc2e1990858a146b60b2","https://git.kernel.org/stable/c/fbf4daa6f4105e01fbd3868006f65c163365c1e3","https://git.kernel.org/stable/c/fe92c058199067ae90cf2a901ddf3c271893557a"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2021-47327","score":0.00255,"percentile":0.17155,"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."]}