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Fencer Vulns
medium 5.5

CVE-2021-4441 json

spi: spi-zynq-qspi: Fix a NULL pointer dereference in zynq_qspi_exec_mem_op()

published 2024-08-22 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-34640

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 13%
public exploits
0
none known

Summary

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

spi: spi-zynq-qspi: Fix a NULL pointer dereference in zynq_qspi_exec_mem_op()

In zynq_qspi_exec_mem_op(), kzalloc() is directly used in memset(), which could lead to a NULL pointer dereference on failure of kzalloc().

Fix this bug by adding a check of tmpbuf.

This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs.

Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug.

Builds with CONFIG_SPI_ZYNQ_QSPI=m show no new warnings, and our static analyzer no longer warns about this code.

Patch / fix

  • Linux Linux 5.4.182, 5.10.103, 5.15.26, 5.16.12, 5.17
  • linux Debian 14, Debian 13, Debian 12 5.16.12-1

debian advisories DEBIAN-CVE-2021-4441

  • linux Ubuntu 20.04 LTS 5.4.0-117.132
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1078.84
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1078.84
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1026.29
  • linux-iot Ubuntu 20.04 LTS 5.4.0-1004.6
  • linux-kvm Ubuntu 20.04 LTS 5.4.0-1068.72
  • linux-azure Ubuntu 20.04 LTS 5.4.0-1083.87
  • linux-gkeop Ubuntu 20.04 LTS 5.4.0-1046.48

ubuntu advisories UBUNTU-CVE-2021-4441

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

  • dtb-aarch64 openSUSE Leap 15.5 5.14.21-150500.55.80.1
  • kernel-64kb SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.80.2
  • kernel-syms SLE Module for Development Tools 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.80.1
  • kernel-obs-qa openSUSE Leap 15.5 5.14.21-150500.55.80.1
  • kernel-source SLE Module for Development Tools 15 SP5, SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.80.2
  • kernel-default SLE Workstation Extension 15 SP5, SLE Module for Legacy 15 SP5, SLE Module for Basesystem 15 SP5 +5 more 5.14.21-150500.55.80.2
  • kernel-kvmsmall openSUSE Leap 15.5 5.14.21-150500.55.80.2
  • kernel-zfcpdump SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.80.2

suse advisories SUSE-SU-2024:3483-1SUSE-SU-2024:3408-1SUSE-SU-2024:3249-1SUSE-SU-2024:3227-1SUSE-SU-2024:3225-1SUSE-SU-2024:3209-1

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-2021-4441 updated cvss 5.5

kernel: spi: spi-zynq-qspi: Fix a NULL pointer dereference in zynq_qspi_exec_mem_op()

  • 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
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 13% 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.