{"id":"CVE-2026-63802","revision":"29f1972e43334e93a8263feee13580c2","records":[{"revision":"29f1972e43334e93a8263feee13580c2","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-63802","aliases":[],"title":"blk-cgroup: fix UAF in __blkcg_rstat_flush()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nblk-cgroup: fix UAF in __blkcg_rstat_flush()\n\nWhen multiple blkgs in the same blkcg are released concurrently,\na use-after-free can occur. The race happens when one blkg's\n__blkcg_rstat_flush() removes another blkg's iostat entries via\nllist_del_all(). The second blkg sees an empty list and proceeds\nto free itself while the first is still iterating over its entries.\n\nMove the flush from __blkg_release() (RCU callback) to blkg_release()\n(before call_rcu). This ensures the RCU grace period waits for any\nconcurrent flush's rcu_read_lock() section to complete before freeing.","state":0,"publishedAt":"2026-07-19T12:02:08.02+00:00","modifiedAt":"2026-10-19T20:07:47.815+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"block/blk-cgroup.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"20cb1c2fb7568a6054c55defe044311397e01ddb\",\n                            \"lessThan\": \"96e545410c4f74c89d496c1d5d9ef8d08f14368b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"20cb1c2fb7568a6054c55defe044311397e01ddb\",\n                            \"lessThan\": \"bbebd9425cad3573d1527441753899b926525a0f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"20cb1c2fb7568a6054c55defe044311397e01ddb\",\n                            \"lessThan\": \"5e5b7f2ef854936e95dceb6a2fdfefcb7152d2c6\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"20cb1c2fb7568a6054c55defe044311397e01ddb\",\n                            \"lessThan\": \"afebe44facc48a61761e885bbb7f0380d4a603ec\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"20cb1c2fb7568a6054c55defe044311397e01ddb\",\n                            \"lessThan\": \"0ab5ee5a1badb58cbb2242617cb01a4972b1f2a2\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"0f6090d90f627d8c58f939067d6c6821ce1b3c68\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"6.3.9\",\n                            \"lessThan\": \"6.4\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"block/blk-cgroup.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.4\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.4\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.144\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.95\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.38\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.3\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/96e545410c4f74c89d496c1d5d9ef8d08f14368b","https://git.kernel.org/stable/c/bbebd9425cad3573d1527441753899b926525a0f","https://git.kernel.org/stable/c/5e5b7f2ef854936e95dceb6a2fdfefcb7152d2c6","https://git.kernel.org/stable/c/afebe44facc48a61761e885bbb7f0380d4a603ec","https://git.kernel.org/stable/c/0ab5ee5a1badb58cbb2242617cb01a4972b1f2a2"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-63802","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-63802","identifiers":["CVE-2026-63802"]},"retained":false,"historicalAffected":[]}],"coverage":[]}