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Fencer Vulns
medium 5.5

CVE-2024-26844 json

block: Fix WARNING in _copy_from_iter

published 2024-04-17 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-24106

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:

block: Fix WARNING in _copy_from_iter

Syzkaller reports a warning in _copy_from_iter because an iov_iter is supposedly used in the wrong direction. The reason is that syzcaller managed to generate a request with a transfer direction of SG_DXFER_TO_FROM_DEV. This instructs the kernel to copy user buffers into the kernel, read into the copied buffers and then copy the data back to user space.

Thus the iovec is used in both directions.

Detect this situation in the block layer and construct a new iterator with the correct direction for the copy-in.

Patch / fix

  • Linux Linux 6.1.80, 6.6.19, 6.7.7, 6.8
  • linux Debian 12 6.1.82-1
  • linux Debian 14, Debian 13 6.7.7-1

debian advisories DEBIAN-CVE-2024-26844

  • linux-raspi-realtime Ubuntu Pro Realtime 24.04 LTS 6.8.0-2001.1

ubuntu advisories UBUNTU-CVE-2024-26844

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-source Linux Micro 6.0 6.4.0-18.1
  • kernel-default Linux Micro 6.0 6.4.0-18.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-18.1
  • kernel-default-base Linux Micro 6.0 6.4.0-17.1.1.51
  • kernel-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.5.1
  • kernel-syms-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.5.1
  • kernel-rt_debug Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.5.1
  • kernel-source-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.5.1

suse advisories SUSE-SU-2025:20008-1SUSE-SU-2024:2973-1SUSE-SU-2024:2203-1SUSE-SU-2024:2135-1

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-2024-26844 updated cvss 4.4

kernel: block: Fix WARNING in _copy_from_iter

  • 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
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-selftests-internal
    affected: no fix available
  • 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, +82 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

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.