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Fencer Vulns
medium 5.5

CVE-2022-49782 json

perf: Improve missing SIGTRAP checking

published 2025-05-01 18 mo ago modified 2026-11-05 3 d ago also EUVD-2025-12994

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

perf: Improve missing SIGTRAP checking

To catch missing SIGTRAP we employ a WARN in __perf_event_overflow(), which fires if pending_sigtrap was already set: returning to user space without consuming pending_sigtrap, and then having the event fire again would re-enter the kernel and trigger the WARN.

This, however, seemed to miss the case where some events not associated with progress in the user space task can fire and the interrupt handler runs before the IRQ work meant to consume pending_sigtrap (and generate the SIGTRAP).

syzbot gifted us this stack trace:

| WARNING: CPU: 0 PID: 3607 at kernel/events/core.c:9313 __perf_event_overflow | Modules linked in: | CPU: 0 PID: 3607 Comm: syz-executor100 Not tainted 6.1.0-rc2-syzkaller-00073-g88619e77b33d #0 | Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 | RIP: 0010:__perf_event_overflow+0x498/0x540 kernel/events/core.c:9313 | <...> | Call Trace: | <TASK> | perf_swevent_hrtimer+0x34f/0x3c0 kernel/events/core.c:10729 | __run_hrtimer kernel/time/hrtimer.c:1685 [inline] | __hrtimer_run_queues+0x1c6/0xfb0 kernel/time/hrtimer.c:1749 | hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 | local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline] | __sysvec_apic_timer_interrupt+0x17c/0x640 arch/x86/kernel/apic/apic.c:1113 | sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1107 | asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 | <...> | </TASK>

In this case, syzbot produced a program with event type PERF_TYPE_SOFTWARE and config PERF_COUNT_SW_CPU_CLOCK. The hrtimer manages to fire again before the IRQ work got a chance to run, all while never having returned to user space.

Improve the WARN to check for real progress in user space: approximate this by storing a 32-bit hash of the current IP into pending_sigtrap, and if an event fires while pending_sigtrap still matches the previous IP, we assume no progress (false negatives are possible given we could return to user space and trigger again on the same IP).

Patch / fix

  • Linux Linux 5.15.80, 6.0.10
  • linux Debian 14, Debian 13, Debian 12 6.0.10-1

debian advisories DEBIAN-CVE-2022-49782

  • linux Ubuntu 22.04 LTS 5.15.0-67.74
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1031.35
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1030.37
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1028.33
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1026.29
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1029.34
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1034.41
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1016.21

ubuntu advisories UBUNTU-CVE-2022-49782

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-49782 updated cvss 4.7

kernel: perf: Improve missing SIGTRAP checking

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
3 d ago

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.