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medium 5.5

CVE-2019-19767 json

The Linux kernel before 5.4.2 mishandles ext4_expand_extra_isize, as demonstrated by use-after-free errors in __ext4_expand_extra_isize and…

published 6y ago modified 4mo ago also EUVD-2019-9367

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.1%
EPSS 2.1% chance of exploitation in 30 days, percentile 81%
public exploits
0
none known

Summary

The Linux kernel before 5.4.2 mishandles ext4_expand_extra_isize, as demonstrated by use-after-free errors in __ext4_expand_extra_isize and ext4_xattr_set_entry, related to fs/ext4/inode.c and fs/ext4/super.c, aka CID-4ea99936a163.

Patch / fix

  • linux linux_kernel 5.4.2
  • linux Debian 14, Debian 13, Debian 12 5.3.15-1

debian advisories DEBIAN-CVE-2019-19767

  • linux Ubuntu 18.04 LTS 4.15.0-88.88
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1060.62
  • linux-gcp Ubuntu 16.04 LTS 4.15.0-1055.59
  • linux-gcp Ubuntu 18.04 LTS 5.0.0-1029.30~18.04.1
  • linux-hwe Ubuntu 16.04 LTS 4.15.0-88.88~16.04.1
  • linux-hwe Ubuntu 18.04 LTS 5.3.0-40.32~18.04.1
  • linux-kvm Ubuntu 18.04 LTS 4.15.0-1053.53
  • linux-oem Ubuntu 18.04 LTS 4.15.0-1073.83

ubuntu advisories UBUNTU-CVE-2019-19767

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-alt RHEL 7 4.14.0-115.26.1.el7a
  • perf RHEL 7 4.14.0-115.26.1.el7a
  • kernel RHEL 7 4.14.0-115.26.1.el7a
  • python-perf RHEL 7 4.14.0-115.26.1.el7a
  • kernel-tools RHEL 7 4.14.0-115.26.1.el7a
  • kernel-tools-libs RHEL 7 4.14.0-115.26.1.el7a
  • kernel-bootwrapper RHEL 7 4.14.0-115.26.1.el7a
  • kernel-abi-whitelists RHEL 7 4.14.0-115.26.1.el7a

red hat advisories RHSA-2020:2854RHSA-2020:4431RHSA-2020:4060RHSA-2020:4609RHSA-2020:4062

  • kernel-syms SLES for SAP 12 SP2, SLES 12 SP2-LTSS, SLES 12 SP2-BCL +1 more 4.4.121-92.129.1
  • kernel-source SLES for SAP 12 SP2, SLES 12 SP2-LTSS, SLES 12 SP2-BCL +1 more 4.4.121-92.129.1
  • kernel-default SLES for SAP 12 SP2, SLES 12 SP2-LTSS, SLES 12 SP2-BCL +2 more 4.4.121-92.129.1
  • kgraft-patch-SLE12-SP2_Update_34 SLES for SAP 12 SP2, SLES 12 SP2-LTSS, OpenStack Cloud 7 1-3.3.1
  • kernel-syms SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +4 more 4.4.180-94.116.1
  • kernel-source SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +4 more 4.4.180-94.116.1
  • kernel-default SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +5 more 4.4.180-94.116.1
  • kgraft-patch-SLE12-SP3_Update_31 SLES for SAP 12 SP3, SLES 12 SP3-LTSS, OpenStack Cloud Crowbar 8 +3 more 1-4.3.1

suse advisories SUSE-SU-2020:1255-1SUSE-SU-2020:1275-1SUSE-SU-2020:0613-1SUSE-SU-2020:0599-1SUSE-SU-2020:0584-1SUSE-SU-2020:0580-1

  • kernel-syms openSUSE Leap 15.1 4.12.14-lp151.28.40.1
  • kernel-obs-qa openSUSE Leap 15.1 4.12.14-lp151.28.40.1
  • kernel-source openSUSE Leap 15.1 4.12.14-lp151.28.40.1
  • kernel-default openSUSE Leap 15.1 4.12.14-lp151.28.40.1
  • kernel-vanilla openSUSE Leap 15.1 4.12.14-lp151.28.40.1
  • kernel-kvmsmall openSUSE Leap 15.1 4.12.14-lp151.28.40.1
  • kernel-obs-build openSUSE Leap 15.1 4.12.14-lp151.28.40.1

opensuse advisories openSUSE-SU-2020:0336-1

Is CVE-2019-19767 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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-2019-19767 updated cvss 5.5

kernel: use-after-free in __ext4_expand_extra_isize and ext4_xattr_set_entry related to fs/ext4/inode.c and fs/ext4/super.c

  • Red Hat Enterprise MRG 2 kernel-rt, mrg-rt-release, kernel-rt-trace, kernel-rt-vanilla, kernel-rt-firmware
    affected: workaround, no fix planned “The mitigation is not to use debug_want_extra_isize parameter when mounting ext4 FS.”
  • Red Hat CodeReady Linux Builder (v. 8) kernel-debuginfo-common-x86_64 4.18.0-240.el8, kernel-debuginfo-common-aarch64 4.18.0-240.el8, kernel-debuginfo-common-ppc64le 4.18.0-240.el8 Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-240.el8, kernel 4.18.0-240.el8, bpftool 4.18.0-240.el8, kernel-core 4.18.0-240.el8, kernel-tools 4.18.0-240.el8, python3-perf 4.18.0-240.el8, +15 more
    fixed: vendor fix “The mitigation is not to use debug_want_extra_isize parameter when mounting ext4 FS.” RHSA-2020:4431
  • Red Hat Enterprise Linux Client (v. 7) perf 3.10.0-1160.el7, kernel 3.10.0-1160.el7, bpftool 3.10.0-1160.el7, python-perf 3.10.0-1160.el7, kernel-tools 3.10.0-1160.el7, kernel-tools-libs 3.10.0-1160.el7, +2 more Red Hat Enterprise Linux Client Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.el7 Red Hat Enterprise Linux ComputeNode (v. 7) perf 3.10.0-1160.el7, kernel 3.10.0-1160.el7, bpftool 3.10.0-1160.el7, python-perf 3.10.0-1160.el7, kernel-tools 3.10.0-1160.el7, kernel-tools-libs 3.10.0-1160.el7, +2 more Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.el7
    fixed: vendor fix “The mitigation is not to use debug_want_extra_isize parameter when mounting ext4 FS.” RHSA-2020:4060
  • Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) perf 4.14.0-115.26.1.el7a, kernel 4.14.0-115.26.1.el7a, kernel-alt 4.14.0-115.26.1.el7a, python-perf 4.14.0-115.26.1.el7a, kernel-tools 4.14.0-115.26.1.el7a, kernel-tools-libs 4.14.0-115.26.1.el7a, +3 more Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) kernel-debuginfo-common-ppc64le 4.14.0-115.26.1.el7a
    fixed: vendor fix “The mitigation is not to use debug_want_extra_isize parameter when mounting ext4 FS.” RHSA-2020:2854
  • Red Hat Enterprise Linux for Real Time (v. 7) kernel-rt 3.10.0-1160.rt56.1131.el7, kernel-rt-trace 3.10.0-1160.rt56.1131.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.rt56.1131.el7 Red Hat Enterprise Linux for Real Time for NFV (v. 7) kernel-rt 3.10.0-1160.rt56.1131.el7, kernel-rt-kvm 3.10.0-1160.rt56.1131.el7, kernel-rt-trace 3.10.0-1160.rt56.1131.el7, kernel-rt-debug-kvm 3.10.0-1160.rt56.1131.el7, kernel-rt-trace-kvm 3.10.0-1160.rt56.1131.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.rt56.1131.el7
    fixed: vendor fix “The mitigation is not to use debug_want_extra_isize parameter when mounting ext4 FS.” RHSA-2020:4062
  • Red Hat Enterprise Linux Real Time (v. 8) kernel-rt 4.18.0-240.rt7.54.el8, kernel-rt-core 4.18.0-240.rt7.54.el8, kernel-rt-modules 4.18.0-240.rt7.54.el8, kernel-rt-debug-core 4.18.0-240.rt7.54.el8, kernel-rt-debug-modules 4.18.0-240.rt7.54.el8, kernel-rt-modules-extra 4.18.0-240.rt7.54.el8, +2 more Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt 4.18.0-240.rt7.54.el8, kernel-rt-kvm 4.18.0-240.rt7.54.el8, kernel-rt-core 4.18.0-240.rt7.54.el8, kernel-rt-modules 4.18.0-240.rt7.54.el8, kernel-rt-debug-kvm 4.18.0-240.rt7.54.el8, kernel-rt-debug-core 4.18.0-240.rt7.54.el8, +4 more
    fixed: vendor fix “The mitigation is not to use debug_want_extra_isize parameter when mounting ext4 FS.” RHSA-2020:4609
  • Red Hat Enterprise Linux Server (v. 7) perf 3.10.0-1160.el7, kernel 3.10.0-1160.el7, bpftool 3.10.0-1160.el7, python-perf 3.10.0-1160.el7, kernel-kdump 3.10.0-1160.el7, kernel-tools 3.10.0-1160.el7, +7 more Red Hat Enterprise Linux Server Optional (v. 7) kernel-debuginfo-common-ppc64 3.10.0-1160.el7, kernel-debuginfo-common-x86_64 3.10.0-1160.el7, kernel-debuginfo-common-ppc64le 3.10.0-1160.el7 Red Hat Enterprise Linux Workstation (v. 7) perf 3.10.0-1160.el7, kernel 3.10.0-1160.el7, bpftool 3.10.0-1160.el7, python-perf 3.10.0-1160.el7, kernel-tools 3.10.0-1160.el7, kernel-tools-libs 3.10.0-1160.el7, +2 more Red Hat Enterprise Linux Workstation Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.el7
    fixed: vendor fix “The mitigation is not to use debug_want_extra_isize parameter when mounting ext4 FS.” RHSA-2020:4060
  • Red Hat Enterprise Linux 5 kernel Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) kernel-headers 4.14.0-115.26.1.el7a
    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

Exploit prediction

2.08% chance of exploitation in the next 30 days, higher than 81% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • bugzilla.kernel.org https://bugzilla.kernel.org/show_bug.cgi?id=205609 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P

Classification

Weakness
Technology feeds

References

Sources

Fencer Intel 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.