kernel: mounting a crafted btrfs filesystem image, performing some operations, and then making a syncfs system call can lead to a use-after-free in try_merge_free_space in fs/btrfs/free-space-cache.c
Published Dec 8, 2019
7.8
HIGHCVSS 3.1
EPSS 2.14%
Description
In the Linux kernel 5.0.21 and 5.3.11, mounting a crafted btrfs filesystem image, performing some operations, and then making a syncfs system call can lead to a use-after-free in try_merge_free_space in fs/btrfs/free-space-cache.c because the pointer to a left data structure can be the same as the pointer to a right data structure.
Affected products
No data.
Configuration 1
- ≥ 2.6.31 · < 4.4.233
- ≥ 4.5.0 · < 4.9.233
- ≥ 4.10 · < 4.14.194
- ≥ 4.15 · < 4.19.141
- ≥ 4.20 · < 5.4.60
- ≥ 5.5.0 · < 5.7.17
- ≥ 5.8 · < 5.8.3
Configuration 2
- 9.0
Configuration 3
- 14.04
- 16.04
- 18.04
Configuration 4
- n/a
- n/a
- n/a
- n/a
- n/a
- n/a
Configuration 5
- n/a
Configuration 6
- n/a
Configuration 7
- n/a
Configuration 8
- n/a
Configuration 9
- n/a
Configuration 10
- n/a
Configuration 11
- n/a
Configuration 12
- n/a
Configuration 13
Running on/with
- n/a
No data.
Red Hat Enterprise Linux 5
kernel
Not affected
Red Hat Enterprise Linux 6
kernel
Out of support scope
Red Hat Enterprise Linux 7
kernel
Not affected
Red Hat Enterprise Linux 7
kernel-alt
Will not fix
Red Hat Enterprise Linux 7
kernel-rt
Not affected
Red Hat Enterprise Linux 8
kernel
Not affected
Red Hat Enterprise Linux 8
kernel-rt
Not affected
Red Hat Enterprise MRG 2
kernel-rt
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 6 | kernel | Out of support scope | n/a |
| Red Hat Enterprise Linux 7 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel-alt | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise MRG 2 | kernel-rt | Will not fix | n/a |
No package ranges for this CVE.
Remediation
Red Hat mitigation
If the system requires this filesystem to work correctly, this mitigation may not be suitable. As the BTRFS module will be auto-loaded when required, autoloading can be prevented by disabling the module, see KCS article https://access.redhat.com/solutions/41278 or contact Red Hat Global Support Services.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
AV:N/AC:M/Au:N/C:P/I:P/A:P
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 3, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Percentile over time
- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Table of values (13 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 3, 2026 | 2.14% (0.02143) | 81.42th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.23% (0.02230) | 80.39th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.24% (0.00243) | 45.64th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.17% (0.00169) | 55.22th | v3 (v2023.03.01) |
| Nov 13, 2023 | 0.12% (0.00119) | 45.82th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.10% (0.00104) | 40.99th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.11% (0.01108) | 55.18th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.11% (0.01108) | 51.54th | v2 (v2022.01.01) |
| Feb 4, 2022 | 2.15% (0.02150) | 56.98th | v2 (v2022.01.01) |
| Feb 3, 2022 | 6.21% (0.06208) | 81.93th | v1 |
| Jan 6, 2022 | 6.21% (0.06208) | 81.75th | v1 |
| Jan 5, 2022 | 1.45% (0.01454) | 72.86th | v5 (v2026.06.15) |
| Apr 14, 2021 | 1.45% (0.01454) | 0.00th | v1 |
References (10)
- https://access.redhat.com/security/cve/CVE-2019-19448 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1781674 Issue Tracking
- https://github.com/bobfuzzer/CVE/tree/master/CVE-2019-19448 x_refsource_MISCExploitThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/09/msg00025.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/10/msg00032.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2019-19448
- https://security.netapp.com/advisory/ntap-20200103-0001/ x_refsource_CONFIRMThird Party Advisory
- https://usn.ubuntu.com/4578-1/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2019-19448
| Link | Providers | Tags |
|---|---|---|
| https://access.redhat.com/security/cve/CVE-2019-19448 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1781674 | Issue Tracking | |
| https://github.com/bobfuzzer/CVE/tree/master/CVE-2019-19448 | x_refsource_MISCExploitThird Party Advisory | |
| https://lists.debian.org/debian-lts-announce/2020/09/msg00025.html | mailing-listx_refsource_MLISTMailing ListThird Party Advisory | |
| https://lists.debian.org/debian-lts-announce/2020/10/msg00032.html | mailing-listx_refsource_MLISTMailing ListThird Party Advisory | |
| https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html | mailing-listx_refsource_MLISTMailing ListThird Party Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2019-19448 | ||
| https://security.netapp.com/advisory/ntap-20200103-0001/ | x_refsource_CONFIRMThird Party Advisory | |
| https://usn.ubuntu.com/4578-1/ | vendor-advisoryx_refsource_UBUNTUThird Party Advisory | |
| https://www.cve.org/CVERecord?id=CVE-2019-19448 |
Change history (0)
No recorded changes yet.