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Fencer Vulns
high 7.5

CVE-2021-47519 json

can: m_can: m_can_read_fifo: fix memory leak in error branch

published 2024-05-24 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-34523

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 42%
public exploits
0
none known

Summary

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

can: m_can: m_can_read_fifo: fix memory leak in error branch

In m_can_read_fifo(), if the second call to m_can_fifo_read() fails, the function jump to the out_fail label and returns without calling m_can_receive_skb(). This means that the skb previously allocated by alloc_can_skb() is not freed. In other terms, this is a memory leak.

This patch adds a goto label to destroy the skb if an error occurs.

Issue was found with GCC -fanalyzer, please follow the link below for details.

Patch / fix

  • Linux Linux 5.15.8, 5.16
  • linux linux_kernel 31cb32a590d6, 75a422165477
  • linux Debian 14, Debian 13, Debian 12 5.15.15-1

debian advisories DEBIAN-CVE-2021-47519

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-2021-47519 updated cvss 5.5

kernel: can: m_can: m_can_read_fifo: fix memory leak in error branch

  • 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 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    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
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.50% chance of exploitation in the next 30 days, higher than 42% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux
  • linux linux_kernel

Classification

Weakness
  • CWE-401 Missing Release of Memory after Effective Lifetime
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.