{"id":"CVE-2026-98552","title":"perf/core: Fix a refcount leak in attach_perf_ctx_data()","summary":"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_d…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 506e64e710ff9573fd2b86686528762b7901b5e4 < 23250517cd475367653f1e99396967f54c6f1b7c","Linux >= 506e64e710ff9573fd2b86686528762b7901b5e4 < 5286d4eb5cd7e10d7d93c3cc596e18bc8ad80f72","Linux >= 506e64e710ff9573fd2b86686528762b7901b5e4 < cca4980630b3c7a85f53cb43c6018184ce5d4e37","Linux 6.15"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:18:19.810Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98552","references":[{"url":"https://git.kernel.org/stable/c/23250517cd475367653f1e99396967f54c6f1b7c"},{"url":"https://git.kernel.org/stable/c/5286d4eb5cd7e10d7d93c3cc596e18bc8ad80f72"},{"url":"https://git.kernel.org/stable/c/cca4980630b3c7a85f53cb43c6018184ce5d4e37"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T15:45:12.264Z","slug":"CVE-2026-98552","body":"## Overview\n\nIn 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().\n\n## Affected\n\n- `Linux >= 506e64e710ff9573fd2b86686528762b7901b5e4 < 23250517cd475367653f1e99396967f54c6f1b7c`\n- `Linux >= 506e64e710ff9573fd2b86686528762b7901b5e4 < 5286d4eb5cd7e10d7d93c3cc596e18bc8ad80f72`\n- `Linux >= 506e64e710ff9573fd2b86686528762b7901b5e4 < cca4980630b3c7a85f53cb43c6018184ce5d4e37`\n- `Linux 6.15`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}