Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix a refcount leak in attach_perf_ctx_data() The attach_perf_ctx_data() can race on global and !global cases. The global case is protected by global_ctx_data_rwsem and shares a single reference count using perf_ctx_data.global field. But when it races with !global case, it may miss to set the global field and result in a reference count leak. CPU1 CPU2 ---------------------------------------------------------------- attach_task_ctx_data(.global=1) attach_task_ctx_data(.global=0) cd1 = alloc_perf_ctx_data(); cd2 = alloc_perf_ctx_data(); // { .global = 0, .refcount = 1 }; try_cmpxchg(); // success, // task->perf_ctx_data = cd2 try_cmpxhg(); // fail; old = cd2 refcount_inc_not_zero(&old->refcount); // success // old.refcount = 2 free_perf_ctx_data(cd1); Then later detach_global_ctx_data() will see the data but it's not marked as global, so it won't call detach_task_ctx_data().
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 506e64e710ff9573fd2b86686528762b7901b5e4 before 23250517cd475367653f1e99396967f54c6f1b7c; affected 506e64e710ff9573fd2b86686528762b7901b5e4 before 5286d4eb5cd7e10d7d93c3cc596e18bc8ad80f72; affected 506e64e710ff9573fd2b86686528762b7901b5e4 before cca4980630b3c7a85f53cb43c6018184ce5d4e37 |
| Linux / Linux | affected 6.15; unaffected 0 before 6.15; unaffected 6.18.55 through 6.18.*; unaffected 7.2.9 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.