CVE-2022-49607

published 2025-02-26

CVE-2022-49607: 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…

Priority P4 15 medium 4.7 CVSS 3.1

AV L AC H PR L UI N S U C N I N A H

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.

Affected

30 ranges · showing 25

Vendor	Product	Version range	Fixed in
debian	linux	< linux 5.18.16-1 (bookworm)	linux 5.18.16-1 (bookworm)
linux	linux	—	—
linux	linux	—	—
linux	linux	—	—
linux	linux	—	—
linux	linux	>= 3.2.49 < 3.3	3.3
linux	linux	>= 3.4.52 < 3.5	3.5
linux	linux	>= 3.9.8 < 3.10	3.10
linux	linux	>= 9bb5d40cd93c9dd4be74834b1dcb1ba03629716b < 3bbd868099287ff9027db59029b502fcfa2202a0	3bbd868099287ff9027db59029b502fcfa2202a0
linux	linux	>= 9bb5d40cd93c9dd4be74834b1dcb1ba03629716b < f836f9ac95df15f1e0af4beb0ec20021e8c91998	f836f9ac95df15f1e0af4beb0ec20021e8c91998
linux	linux	>= 9bb5d40cd93c9dd4be74834b1dcb1ba03629716b < 17f5417194136517ee9bbd6511249e5310e5617c	17f5417194136517ee9bbd6511249e5310e5617c
linux	linux	>= 9bb5d40cd93c9dd4be74834b1dcb1ba03629716b < 98c3c8fd0d4c560e0f8335b79c407bbf7fc9462c	98c3c8fd0d4c560e0f8335b79c407bbf7fc9462c
linux	linux	>= 9bb5d40cd93c9dd4be74834b1dcb1ba03629716b < 43128b3eee337824158f34da6648163d2f2fb937	43128b3eee337824158f34da6648163d2f2fb937
linux	linux	>= 9bb5d40cd93c9dd4be74834b1dcb1ba03629716b < da3c256e2d0ebc87c7db0c605c9692b6f1722074	da3c256e2d0ebc87c7db0c605c9692b6f1722074
linux	linux	>= 9bb5d40cd93c9dd4be74834b1dcb1ba03629716b < a9391ff7a7c5f113d6f2bf6621d49110950de49c	a9391ff7a7c5f113d6f2bf6621d49110950de49c
linux	linux	>= 9bb5d40cd93c9dd4be74834b1dcb1ba03629716b < 68e3c69803dada336893640110cb87221bb01dcf	68e3c69803dada336893640110cb87221bb01dcf
linux	linux_kernel	—	—
linux	linux_kernel	>= 0 < 5.10.136-1	5.10.136-1
linux	linux_kernel	>= 0 < 5.18.16-1	5.18.16-1
linux	linux_kernel	>= 0 < 5.18.16-1	5.18.16-1
linux	linux_kernel	>= 0 < 5.18.16-1	5.18.16-1
linux	linux_kernel	>= 3.2.49 < 3.3	3.3
linux	linux_kernel	>= 3.4.52 < 3.5	3.5
linux	linux_kernel	>= 3.9.8 < 4.9.325	4.9.325
linux	linux_kernel	>= 4.10 < 4.14.290	4.14.290

CVSS provenance

nvd v3.1 4.7 MEDIUM CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

osv 4.7 MEDIUM

vendor_debian 4.7 MEDIUM

vendor_redhat 4.7 MEDIUM

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