{"id":"CVE-2022-49607","summary":"perf/core: Fix data race between perf_event_set_output() and perf_mmap_close()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf/core: Fix data race between perf_event_set_output() and perf_mmap_close()\n\nYang Jihing reported a race between perf_event_set_output() and\nperf_mmap_close():\n\n\tCPU1\t\t\t\t\tCPU2\n\n\tperf_mmap_close(e2)\n\t  if (atomic_dec_and_test(&e2-\u003erb-\u003emmap_count)) // 1 - \u003e 0\n\t    detach_rest = true\n\n\t\t\t\t\t\tioctl(e1, IOC_SET_OUTPUT, e2)\n\t\t\t\t\t\t  perf_event_set_output(e1, e2)\n\n\t  ...\n\t  list_for_each_entry_rcu(e, &e2-\u003erb-\u003eevent_list, rb_entry)\n\t    ring_buffer_attach(e, NULL);\n\t    // e1 isn't yet added and\n\t    // therefore not detached\n\n\t\t\t\t\t\t    ring_buffer_attach(e1, e2-\u003erb)\n\t\t\t\t\t\t      list_add_rcu(&e1-\u003erb_entry,\n\t\t\t\t\t\t\t\t   &e2-\u003erb-\u003eevent_list)\n\nAfter this; e1 is attached to an unmapped rb and a subsequent\nperf_mmap() will loop forever more:\n\n\tagain:\n\t\tmutex_lock(&e-\u003emmap_mutex);\n\t\tif (event-\u003erb) {\n\t\t\t...\n\t\t\tif (!atomic_inc_not_zero(&e-\u003erb-\u003emmap_count)) {\n\t\t\t\t...\n\t\t\t\tmutex_unlock(&e-\u003emmap_mutex);\n\t\t\t\tgoto again;\n\t\t\t}\n\t\t}\n\nThe loop in perf_mmap_close() holds e2-\u003emmap_mutex, while the attach\nin perf_event_set_output() holds e1-\u003emmap_mutex. As such there is no\nserialization to avoid this race.\n\nChange perf_event_set_output() to take both e1-\u003emmap_mutex and\ne2-\u003emmap_mutex to alleviate that problem. Additionally, have the loop\nin perf_mmap() detach the rb directly, this avoids having to wait for\nthe concurrent perf_mmap_close() to get around to doing it to make\nprogress.","modified":"2026-10-28T02:31:11.860303849Z","published":"2025-02-26T02:23:31.823Z","related":["SUSE-SU-2025:1027-1","SUSE-SU-2025:1176-1","SUSE-SU-2025:1183-1","SUSE-SU-2025:1241-1","SUSE-SU-2025:1293-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49607.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/17f5417194136517ee9bbd6511249e5310e5617c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3bbd868099287ff9027db59029b502fcfa2202a0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/43128b3eee337824158f34da6648163d2f2fb937"},{"type":"WEB","url":"https://git.kernel.org/stable/c/68e3c69803dada336893640110cb87221bb01dcf"},{"type":"WEB","url":"https://git.kernel.org/stable/c/98c3c8fd0d4c560e0f8335b79c407bbf7fc9462c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a9391ff7a7c5f113d6f2bf6621d49110950de49c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/da3c256e2d0ebc87c7db0c605c9692b6f1722074"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f836f9ac95df15f1e0af4beb0ec20021e8c91998"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49607.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-49607"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"9bb5d40cd93c9dd4be74834b1dcb1ba03629716b"},{"fixed":"3bbd868099287ff9027db59029b502fcfa2202a0"},{"fixed":"f836f9ac95df15f1e0af4beb0ec20021e8c91998"},{"fixed":"17f5417194136517ee9bbd6511249e5310e5617c"},{"fixed":"98c3c8fd0d4c560e0f8335b79c407bbf7fc9462c"},{"fixed":"43128b3eee337824158f34da6648163d2f2fb937"},{"fixed":"da3c256e2d0ebc87c7db0c605c9692b6f1722074"},{"fixed":"a9391ff7a7c5f113d6f2bf6621d49110950de49c"},{"fixed":"68e3c69803dada336893640110cb87221bb01dcf"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"3.2.49"},{"fixed":"3.3"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"3.4.52"},{"fixed":"3.5"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"3.9.8"},{"fixed":"3.10"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"2487f0db30527032c4d56fc2d0b1a240fe89fef8"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"703197b61d05f5edae54bad3256901c5a5c8794c"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"c52217e88ae0f3a4ae00562d86e338f8f85969b4"}]}],"versions":["v3.2.102","v3.2.101","v3.2.100","v3.2.99","v3.2.98","v3.2.97","v3.2.96","v3.2.95","v3.2.94","v3.2.93","v3.2.92","v3.2.91","v3.2.90","v3.2.89","v3.2.88","v3.2.87","v3.2.86","v3.2.85","v3.2.84","v3.2.83","v3.2.82","v3.2.81","v3.2.80","v3.2.79","v3.2.78","v3.2.77","v3.2.76","v3.2.75","v3.2.74","v3.2.73","v3.2.72","v3.2.71","v3.2.70","v3.2.69","v3.2.68","v3.2.67","v3.2.66","v3.2.65","v3.2.64","v3.2.63","v3.2.62","v3.2.61","v3.2.60","v3.2.59","v3.2.58","v3.2.57","v3.2.56","v3.2.55","v3.2.54","v3.2.53","v3.2.52","v3.2.51","v3.2.50","v3.2.49","v3.4.113","v3.4.112","v3.4.111","v3.4.110","v3.4.109","v3.4.108","v3.4.107","v3.4.106","v3.4.105","v3.4.104","v3.4.103","v3.4.102","v3.4.101","v3.4.100","v3.4.99","v3.4.98","v3.4.97","v3.4.96","v3.4.95","v3.4.94","v3.4.93","v3.4.92","v3.4.91","v3.4.90","v3.4.89","v3.4.88","v3.4.87","v3.4.86","v3.4.85","v3.4.84","v3.4.83","v3.4.82","v3.4.81","v3.4.80","v3.4.79","v3.4.78","v3.4.77","v3.4.76","v3.4.75","v3.4.74","v3.4.73","v3.4.72","v3.4.71","v3.4.70","v3.4.69","v3.4.68","v3.4.67","v3.4.66","v3.4.65","v3.4.64","v3.4.63","v3.4.62","v3.4.61","v3.4.60","v3.4.59","v3.4.58","v3.4.57","v3.4.56","v3.4.55","v3.4.54","v3.4.53","v3.4.52","v3.9.11","v3.9.10","v3.9.9","v3.9.8"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-49607.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.10.0"},{"fixed":"4.9.325"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.10.0"},{"fixed":"4.14.290"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.15.0"},{"fixed":"4.19.254"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.20.0"},{"fixed":"5.4.208"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.10.134"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.58"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"5.18.15"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-49607.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}