CVSS 4.7 · Medium EPSS 0,19%
Kerentanan Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') pada linux kernel. Skor CVSS 3.1 4.7 (Medium) menurut NVD.
In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix data race between perf_event_set_output() and perf_mmap_close() Yang Jihing reported a race between perf_event_set_output() and perf_mmap_close(): CPU1 CPU2 perf_mmap_close(e2) if (atomic_dec_and_test(&e2->rb->mmap_count)) // 1 - > 0 detach_rest = true ioctl(e1, IOC_SET_OUTPUT, e2) perf_event_set_output(e1, e2) ... list_for_each_entry_rcu(e, &e2->rb->event_list, rb_entry) ring_buffer_attach(e, NULL); // e1 isn't yet added and // therefore not detached ring_buffer_attach(e1, e2->rb) list_add_rcu(&e1->rb_entry, &e2->rb->event_list) After this; e1 is attached to an unmapped rb and a subsequent perf_mmap() will loop forever more: again: mutex_lock(&e->mmap_mutex); if (event->rb) { ... if (!atomic_inc_not_zero(&e->rb->mmap_count)) { ... mutex_unlock(&e->mmap_mutex); goto again; } } The loop in perf_mmap_close() holds e2->mmap_mutex, while the attach in perf_event_set_output() holds e1->mmap_mutex. As such there is no serialization to avoid this race. Change perf_event_set_output() to take both e1->mmap_mutex and e2->mmap_mutex to alleviate that problem. Additionally, have the loop in perf_mmap() detach the rb directly, this avoids having to wait for the concurrent perf_mmap_close() to get around to doing it to make progress.
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
· uraikan di kalkulator | Vendor | Produk | Versi terdampak |
|---|---|---|
| linux | linux kernel | Versi 3.2.49 hingga sebelum 3.3 |
| linux | linux kernel | Versi 3.4.52 hingga sebelum 3.5 |
| linux | linux kernel | Versi 3.9.8 hingga sebelum 4.9.325 |
| linux | linux kernel | Versi 4.10 hingga sebelum 4.14.290 |
| linux | linux kernel | Versi 4.15 hingga sebelum 4.19.254 |
| linux | linux kernel | Versi 4.20 hingga sebelum 5.4.208 |
| linux | linux kernel | Versi 5.5 hingga sebelum 5.10.134 |
| linux | linux kernel | Versi 5.11 hingga sebelum 5.15.58 |
| linux | linux kernel | Versi 5.16 hingga sebelum 5.18.15 |
| linux | linux kernel | Versi 5.19 rc1 |
| linux | linux kernel | Versi 5.19 rc2 |
| linux | linux kernel | Versi 5.19 rc3 |
| linux | linux kernel | Versi 5.19 rc4 |
| linux | linux kernel | Versi 5.19 rc5 |
| linux | linux kernel | Versi 5.19 rc6 |