Skip to content
Fencer Vulns
high 7.8

CVE-2022-50255 json

tracing: Fix reading strings from synthetic events

published 2025-09-15 13 mo ago modified 2026-10-15 24 d ago also EUVD-2022-55497

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits
0
none known

Summary

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

tracing: Fix reading strings from synthetic events

The follow commands caused a crash:

# cd /sys/kernel/tracing # echo 's:open char file[]' > dynamic_events # echo 'hist:keys=common_pid:file=filename:onchange($file).trace(open,$file)' > events/syscalls/sys_enter_openat/trigger' # echo 1 > events/synthetic/open/enable

BOOM!

The problem is that the synthetic event field "char file[]" will read the value given to it as a string without any memory checks to make sure the address is valid. The above example will pass in the user space address and the sythetic event code will happily call strlen() on it and then strscpy() where either one will cause an oops when accessing user space addresses.

Use the helper functions from trace_kprobe and trace_eprobe that can read strings safely (and actually succeed when the address is from user space and the memory is mapped in).

Now the above can show:

packagekitd-1721 [000] ...2. 104.597170: open: file=/usr/lib/rpm/fileattrs/cmake.attr in:imjournal-978 [006] ...2. 104.599642: open: file=/var/lib/rsyslog/imjournal.state.tmp packagekitd-1721 [000] ...2. 104.626308: open: file=/usr/lib/rpm/fileattrs/debuginfo.attr

Patch / fix

  • Linux Linux 5.15.75, 5.19.17, 6.0.3, 6.1
  • linux Debian 14, Debian 13, Debian 12 6.0.3-1

debian advisories DEBIAN-CVE-2022-50255

  • linux Ubuntu 22.04 LTS 5.15.0-60.66
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1030.34
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1029.36
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1027.32
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1025.28
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1028.33
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1033.40
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1015.19

ubuntu advisories UBUNTU-CVE-2022-50255

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

  • kernel-rt SLE Micro 5.5 5.14.21-150500.13.109.1
  • kernel-source-rt SLE Micro 5.5 5.14.21-150500.13.109.1
  • kernel-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.133.1
  • kernel-source-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.133.1
  • kernel-64kb SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS, SLE High Performance Computing 15 SP4-ESPOS 5.14.21-150400.24.179.1
  • kernel-syms SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.179.1
  • kernel-source SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.179.1
  • kernel-default SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +7 more 5.14.21-150400.24.179.1

suse advisories SUSE-SU-2025:3761-1SUSE-SU-2025:3716-1SUSE-SU-2025:03628-1SUSE-SU-2025:03615-1

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-2022-50255 updated cvss 5.5

kernel: tracing: Fix reading strings from synthetic events

  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: no fix available “Fix deferred”
  • 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 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
total
Assessed
24 d ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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.