CVE-2019-19767: Use After Free

Published Nov 7, 2019
·
Updated

A use-after-free flaw was found in the Linux kernel’s ext4 file system functionality when the user mount ext4 partition, with the usage of an additional debug parameter is defining an extra inode size. If this parameter has a non zero value, this flaw allows a local user to crash the system when inode expansion happens.

Other sources

The Linux kernel before 5.4.2 mishandles ext4expandextraisize, as demonstrated by use-after-free errors in ext4expandextraisize and ext4xattrsetentry, related to fs/ext4/inode.c and fs/ext4/super.c, aka CID-4ea99936a163.

— Ubuntu

The Linux kernel before 5.4.2 mishandles ext4expandextraisize, as demonstrated by use-after-free errors in ext4expandextraisize and ext4xattrsetentry, related to fs/ext4/inode.c and fs/ext4/super.c.

References: https://bugzilla.kernel.org/showbug.cgi?id=205609 https://bugzilla.kernel.org/showbug.cgi?id=205707

Upstream commit: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=4ea99936a1630f51fc3a2d61a58ec4a1c4b7d55a

— Red Hat

Affected Software

49 affected componentsFixes available
redhat/kernel-rt<0:3.10.0-1160.rt56.1131.el7
0:3.10.0-1160.rt56.1131.el7
redhat/kernel-alt<0:4.14.0-115.26.1.el7a
0:4.14.0-115.26.1.el7a
redhat/kernel<0:3.10.0-1160.el7
0:3.10.0-1160.el7
redhat/kernel-rt<0:4.18.0-240.rt7.54.el8
0:4.18.0-240.rt7.54.el8
redhat/kernel<0:4.18.0-240.el8
0:4.18.0-240.el8
Linux Linux kernel<5.4.2
debian/linux
6.1.176-16.1.190-16.12.107-16.12.113-17.2.12-17.2.13-1
ubuntu/linux-azure<4.15.0-1071.76~14.04.1
4.15.0-1071.76~14.04.1
ubuntu/linux-aws-hwe<4.15.0-1060.62~16.04.1
4.15.0-1060.62~16.04.1
ubuntu/linux-azure<4.15.0-1071.76
4.15.0-1071.76
ubuntu/linux-gcp<4.15.0-1055.59
4.15.0-1055.59
ubuntu/linux-hwe<4.15.0-88.88~16.04.1
4.15.0-88.88~16.04.1
ubuntu/linux-oracle<4.15.0-1033.36~16.04.1
4.15.0-1033.36~16.04.1
ubuntu/linux-hwe-edge*
ubuntu/linux<4.15.0-88.88
4.15.0-88.88
ubuntu/linux-aws<4.15.0-1060.62
4.15.0-1060.62
ubuntu/linux-aws-5.0<5.0.0-1024.27~18.04.1
5.0.0-1024.27~18.04.1
ubuntu/linux-azure<5.0.0-1029.31~18.04.1
5.0.0-1029.31~18.04.1
ubuntu/linux-azure-5.3<5.3.0-1013.14~18.04.1
5.3.0-1013.14~18.04.1
ubuntu/linux-gcp<5.0.0-1029.30~18.04.1
5.0.0-1029.30~18.04.1
ubuntu/linux-gcp-5.3<5.3.0-1012.13~18.04.1
5.3.0-1012.13~18.04.1
ubuntu/linux-gke-4.15<4.15.0-1052.55
4.15.0-1052.55
ubuntu/linux-gke-5.0<5.0.0-1029.30~18.04.1
5.0.0-1029.30~18.04.1
ubuntu/linux-gke-5.3<5.3.0-1012.13~18.04.1
5.3.0-1012.13~18.04.1
ubuntu/linux-hwe<5.3.0-40.32~18.04.1
5.3.0-40.32~18.04.1
ubuntu/linux-kvm<4.15.0-1053.53
4.15.0-1053.53
ubuntu/linux-oem<4.15.0-1073.83
4.15.0-1073.83
ubuntu/linux-oem-osp1<5.0.0-1037.42
5.0.0-1037.42
ubuntu/linux-oracle<4.15.0-1033.36
4.15.0-1033.36
ubuntu/linux-oracle-5.0<5.0.0-1010.15~18.04.1
5.0.0-1010.15~18.04.1
ubuntu/linux-raspi2<4.15.0-1055.59
4.15.0-1055.59
ubuntu/linux-raspi2-5.3<5.3.0-1018.20~18.04.1
5.3.0-1018.20~18.04.1
ubuntu/linux-snapdragon<4.15.0-1072.79
4.15.0-1072.79
ubuntu/linux-azure-edge*
ubuntu/linux-gcp-edge*
ubuntu/linux-hwe-edge*
ubuntu/linux-aws-fips<4.15.0-2018.18
4.15.0-2018.18
ubuntu/linux-azure-fips<4.15.0-2006.7
4.15.0-2006.7
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux-azure-fde*
ubuntu/linux-gke*
ubuntu/linux-raspi2*
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-raspi-realtime*
ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade redhat/kernel-rt to a version that resolves this vulnerability.

    Fixed in 0:3.10.0-1160.rt56.1131.el7
  2. Upgrade

    Upgrade redhat/kernel-alt to a version that resolves this vulnerability.

    Fixed in 0:4.14.0-115.26.1.el7a
  3. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 0:3.10.0-1160.el7
  4. Upgrade

    Upgrade redhat/kernel-rt to a version that resolves this vulnerability.

    Fixed in 0:4.18.0-240.rt7.54.el8
  5. Upgrade

    Upgrade redhat/kernel to a version that resolves this vulnerability.

    Fixed in 0:4.18.0-240.el8
  6. Upgrade

    Upgrade debian/linux to a version that resolves this vulnerability.

    Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.113-1Fixed in 7.2.12-1Fixed in 7.2.13-1
  7. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 4.15.0-1071.76~14.04.1
  8. Upgrade

    Upgrade ubuntu/linux-aws-hwe to a version that resolves this vulnerability.

    Fixed in 4.15.0-1060.62~16.04.1
  9. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 4.15.0-1071.76
  10. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 4.15.0-1055.59
  11. Upgrade

    Upgrade ubuntu/linux-hwe to a version that resolves this vulnerability.

    Fixed in 4.15.0-88.88~16.04.1
  12. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 4.15.0-1033.36~16.04.1
  13. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 4.15.0-88.88
  14. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 4.15.0-1060.62
  15. Upgrade

    Upgrade ubuntu/linux-aws-5.0 to a version that resolves this vulnerability.

    Fixed in 5.0.0-1024.27~18.04.1
  16. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 5.0.0-1029.31~18.04.1
  17. Upgrade

    Upgrade ubuntu/linux-azure-5.3 to a version that resolves this vulnerability.

    Fixed in 5.3.0-1013.14~18.04.1
  18. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 5.0.0-1029.30~18.04.1
  19. Upgrade

    Upgrade ubuntu/linux-gcp-5.3 to a version that resolves this vulnerability.

    Fixed in 5.3.0-1012.13~18.04.1
  20. Upgrade

    Upgrade ubuntu/linux-gke-4.15 to a version that resolves this vulnerability.

    Fixed in 4.15.0-1052.55
  21. Upgrade

    Upgrade ubuntu/linux-gke-5.0 to a version that resolves this vulnerability.

    Fixed in 5.0.0-1029.30~18.04.1
  22. Upgrade

    Upgrade ubuntu/linux-gke-5.3 to a version that resolves this vulnerability.

    Fixed in 5.3.0-1012.13~18.04.1
  23. Upgrade

    Upgrade ubuntu/linux-hwe to a version that resolves this vulnerability.

    Fixed in 5.3.0-40.32~18.04.1
  24. Upgrade

    Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.

    Fixed in 4.15.0-1053.53
  25. Upgrade

    Upgrade ubuntu/linux-oem to a version that resolves this vulnerability.

    Fixed in 4.15.0-1073.83
  26. Upgrade

    Upgrade ubuntu/linux-oem-osp1 to a version that resolves this vulnerability.

    Fixed in 5.0.0-1037.42
  27. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 4.15.0-1033.36
  28. Upgrade

    Upgrade ubuntu/linux-oracle-5.0 to a version that resolves this vulnerability.

    Fixed in 5.0.0-1010.15~18.04.1
  29. Upgrade

    Upgrade ubuntu/linux-raspi2 to a version that resolves this vulnerability.

    Fixed in 4.15.0-1055.59
  30. Upgrade

    Upgrade ubuntu/linux-raspi2-5.3 to a version that resolves this vulnerability.

    Fixed in 5.3.0-1018.20~18.04.1
  31. Upgrade

    Upgrade ubuntu/linux-snapdragon to a version that resolves this vulnerability.

    Fixed in 4.15.0-1072.79
  32. Upgrade

    Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.

    Fixed in 4.15.0-2018.18
  33. Upgrade

    Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.

    Fixed in 4.15.0-2006.7
  34. Upgrade

    Upgrade Linux kernel to a version that resolves this vulnerability.

    Fixed in 5.4.2
  35. Configuration

    Do not use the debug_want_extra_isize parameter when mounting ext4 filesystems.

    Linux kernel ext4 filesystem debug_want_extra_isize = not used

Event History

Nov 7, 2019
CVE Published
12:00 AM
Dec 12, 2019
Data Sourced
via Ubuntu·12:00 AM
RemedyDescriptionSeverityAffected Software
CVE Published
via MITRE·07:39 PM
Data Sourced
via MITRE·07:39 PM
Description
Data Sourced
via OSV·08:15 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·08:15 PM
RemedyDescriptionSeverityWeaknessAffected Software
Dec 23, 2019
Data Sourced
via Red Hat·05:19 PM
DescriptionSeverityAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

What is the severity of CVE-2019-19767?

CVE-2019-19767 is classified as a high severity vulnerability due to its potential to cause system crashes.

2

How do I fix CVE-2019-19767?

To fix CVE-2019-19767, update your Linux kernel to the latest versions provided by your distribution, specifically to versions 0:3.10.0-1160.rt56.1131.el7, 0:4.14.0-115.26.1.el7a, or any later secure releases.

3

Who is affected by CVE-2019-19767?

CVE-2019-19767 affects local users of Linux systems using specific versions of the kernel with the ext4 file system.

4

What does CVE-2019-19767 exploit?

CVE-2019-19767 exploits a use-after-free vulnerability in the ext4 file system when an additional debug parameter is enabled.

5

Is there a risk of remote exploitation with CVE-2019-19767?

CVE-2019-19767 does not pose a risk of remote exploitation as it requires local access to the system.

Company

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Contact

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