{"id":"CVE-2025-21745","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nblk-cgroup: Fix class @block_class's subsystem refcount leakage\n\nblkcg_fill_root_iostats() iterates over @block_class's devices by\nclass_dev_iter_(init|next)(), but doe…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nblk-cgroup: Fix class @block_class's subsystem refcount leakage\n\nblkcg_fill_root_iostats() iterates over @block_class's devices by\nclass_dev_iter_(init|next)(), but doe…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.9, < 6.1.129","linux_kernel >= 6.2, < 6.6.78","linux_kernel >= 6.7, < 6.12.14","linux_kernel >= 6.13, < 6.13.3"],"patched":["linux_kernel 6.13.3"],"published":"2025-02-27","updated":"2026-07-14","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-21745","references":[{"url":"https://git.kernel.org/stable/c/2ce09aabe009453d641a2ceb79e6461a2d4f3876","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/38287f779b34dfe959b4b681e909f2d3d52b88be","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/431b6ef2714be4d5babb802114987541a88b43b0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/67c7f213e052b1aa6caba4a7e25e303bc6997126","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/993121481b5a87829f1e8163f47158b72679f309","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d1248436cbef1f924c04255367ff4845ccd9025e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ffb494f1e7a047bd7a41b13796fcfb08fe5beafb","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-082556.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-265688.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00251,"epssPercentile":0.16865,"ingestedAt":"2026-07-14T13:36:55.622Z","slug":"CVE-2025-21745","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nblk-cgroup: Fix class @block_class's subsystem refcount leakage\n\nblkcg_fill_root_iostats() iterates over @block_class's devices by\nclass_dev_iter_(init|next)(), but does not end iterating with\nclass_dev_iter_exit(), so causes the class's subsystem refcount leakage.\n\nFix by ending the iterating with class_dev_iter_exit().\n\n## Affected\n\n- `linux_kernel >= 5.9, < 6.1.129`\n- `linux_kernel >= 6.2, < 6.6.78`\n- `linux_kernel >= 6.7, < 6.12.14`\n- `linux_kernel >= 6.13, < 6.13.3`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.13.3`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}