{"id":"CVE-2026-98552","summary":"perf/core: Fix a refcount leak in attach_perf_ctx_data()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf/core: Fix a refcount leak in attach_perf_ctx_data()\n\nThe attach_perf_ctx_data() can race on global and !global cases.  The\nglobal case is protected by global_ctx_data_rwsem and shares a single\nreference count using perf_ctx_data.global field.\n\nBut when it races with !global case, it may miss to set the global field\nand result in a reference count leak.\n\n CPU1                                  CPU2\n ----------------------------------------------------------------\n attach_task_ctx_data(.global=1)       attach_task_ctx_data(.global=0)\n   cd1 = alloc_perf_ctx_data();          cd2 = alloc_perf_ctx_data();\n                                         //    { .global = 0, .refcount = 1 };\n\n                                         try_cmpxchg(); // success,\n                                         // task-\u003eperf_ctx_data = cd2\n   try_cmpxhg(); // fail; old = cd2\n   refcount_inc_not_zero(&old-\u003erefcount); // success\n     // old.refcount = 2\n   free_perf_ctx_data(cd1);\n\nThen later detach_global_ctx_data() will see the data but it's not\nmarked as global, so it won't call detach_task_ctx_data().","modified":"2026-10-20T02:31:02.871349099Z","published":"2026-10-18T15:18:19.810Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98552.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/23250517cd475367653f1e99396967f54c6f1b7c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5286d4eb5cd7e10d7d93c3cc596e18bc8ad80f72"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cca4980630b3c7a85f53cb43c6018184ce5d4e37"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98552.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98552"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"506e64e710ff9573fd2b86686528762b7901b5e4"},{"fixed":"23250517cd475367653f1e99396967f54c6f1b7c"},{"fixed":"5286d4eb5cd7e10d7d93c3cc596e18bc8ad80f72"},{"fixed":"cca4980630b3c7a85f53cb43c6018184ce5d4e37"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98552.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.15.0"},{"fixed":"6.18.55"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98552.json"}}],"schema_version":"1.9.0"}