{"id":"CVE-2026-98552","published":"2026-10-18T16:17:07.267","lastModified":"2026-10-19T10:19:11.487","description":"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->perf_ctx_data = cd2\n   try_cmpxhg(); // fail; old = cd2\n   refcount_inc_not_zero(&old->refcount); // 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().","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/23250517cd475367653f1e99396967f54c6f1b7c","tags":[]},{"url":"https://git.kernel.org/stable/c/5286d4eb5cd7e10d7d93c3cc596e18bc8ad80f72","tags":[]},{"url":"https://git.kernel.org/stable/c/cca4980630b3c7a85f53cb43c6018184ce5d4e37","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}