| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2022-49607: perf/core: Fix data race between perf_event_set_output() and perf_mmap_close() |
| |
| Description |
| =========== |
| |
| 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. |
| |
| The Linux kernel CVE team has assigned CVE-2022-49607 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 3.10 with commit 9bb5d40cd93c9dd4be74834b1dcb1ba03629716b and fixed in 4.9.325 with commit 3bbd868099287ff9027db59029b502fcfa2202a0 |
| Issue introduced in 3.10 with commit 9bb5d40cd93c9dd4be74834b1dcb1ba03629716b and fixed in 4.14.290 with commit f836f9ac95df15f1e0af4beb0ec20021e8c91998 |
| Issue introduced in 3.10 with commit 9bb5d40cd93c9dd4be74834b1dcb1ba03629716b and fixed in 4.19.254 with commit 17f5417194136517ee9bbd6511249e5310e5617c |
| Issue introduced in 3.10 with commit 9bb5d40cd93c9dd4be74834b1dcb1ba03629716b and fixed in 5.4.208 with commit 98c3c8fd0d4c560e0f8335b79c407bbf7fc9462c |
| Issue introduced in 3.10 with commit 9bb5d40cd93c9dd4be74834b1dcb1ba03629716b and fixed in 5.10.134 with commit 43128b3eee337824158f34da6648163d2f2fb937 |
| Issue introduced in 3.10 with commit 9bb5d40cd93c9dd4be74834b1dcb1ba03629716b and fixed in 5.15.58 with commit da3c256e2d0ebc87c7db0c605c9692b6f1722074 |
| Issue introduced in 3.10 with commit 9bb5d40cd93c9dd4be74834b1dcb1ba03629716b and fixed in 5.18.15 with commit a9391ff7a7c5f113d6f2bf6621d49110950de49c |
| Issue introduced in 3.10 with commit 9bb5d40cd93c9dd4be74834b1dcb1ba03629716b and fixed in 5.19 with commit 68e3c69803dada336893640110cb87221bb01dcf |
| Issue introduced in 3.2.49 with commit 2487f0db30527032c4d56fc2d0b1a240fe89fef8 |
| Issue introduced in 3.4.52 with commit 703197b61d05f5edae54bad3256901c5a5c8794c |
| Issue introduced in 3.9.8 with commit c52217e88ae0f3a4ae00562d86e338f8f85969b4 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2022-49607 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| kernel/events/core.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/3bbd868099287ff9027db59029b502fcfa2202a0 |
| https://git.kernel.org/stable/c/f836f9ac95df15f1e0af4beb0ec20021e8c91998 |
| https://git.kernel.org/stable/c/17f5417194136517ee9bbd6511249e5310e5617c |
| https://git.kernel.org/stable/c/98c3c8fd0d4c560e0f8335b79c407bbf7fc9462c |
| https://git.kernel.org/stable/c/43128b3eee337824158f34da6648163d2f2fb937 |
| https://git.kernel.org/stable/c/da3c256e2d0ebc87c7db0c605c9692b6f1722074 |
| https://git.kernel.org/stable/c/a9391ff7a7c5f113d6f2bf6621d49110950de49c |
| https://git.kernel.org/stable/c/68e3c69803dada336893640110cb87221bb01dcf |
