# CVE-2021-3739: linux: A NULL pointer dereference flaw was found in the btrfs_rm_device function in fs/btrfs/volumes.c in the Linux Kernel,...

CVE-2021-3739 is fixed in 12 products on 1 platform, first by ELSA-2021-9457, released September 22, 2021. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-3739
- Priority: High
- CVSS: 7.1 (high)
- EPSS: 0.0062
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 22, 2021

## Description

A NULL pointer dereference flaw was found in the btrfs_rm_device function in fs/btrfs/volumes.c in the Linux Kernel, where triggering the bug requires ‘CAP_SYS_ADMIN’. This flaw allows a local attacker to crash the system or leak kernel internal information. The highest threat from this vulnerability is to system availability.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | kernel-uek ol 8 | 0:5.4.17-2102.205.7.3.el8uek | [ELSA-2021-9457](https://patchblox.com/security/data/fix/linux/elsa-2021-9457.md) | Sep 22, 2021 |
| Linux | kernel-uek-container ol 8 | 0:5.4.17-2102.205.7.3.el8 | [ELSA-2021-9461](https://patchblox.com/security/data/fix/linux/elsa-2021-9461.md) | Sep 22, 2021 |
| Linux | kernel-uek-container-debug ol 8 | 0:5.4.17-2102.205.7.3.el8 | [ELSA-2021-9461](https://patchblox.com/security/data/fix/linux/elsa-2021-9461.md) | Sep 22, 2021 |
| Linux | kernel-uek-debug ol 8 | 0:5.4.17-2102.205.7.3.el8uek | [ELSA-2021-9457](https://patchblox.com/security/data/fix/linux/elsa-2021-9457.md) | Sep 22, 2021 |
| Linux | kernel-uek-debug-devel ol 8 | 0:5.4.17-2102.205.7.3.el8uek | [ELSA-2021-9457](https://patchblox.com/security/data/fix/linux/elsa-2021-9457.md) | Sep 22, 2021 |
| Linux | kernel-uek-devel ol 8 | 0:5.4.17-2102.205.7.3.el8uek | [ELSA-2021-9457](https://patchblox.com/security/data/fix/linux/elsa-2021-9457.md) | Sep 22, 2021 |
| Linux | kernel-uek-doc ol 8 | 0:5.4.17-2102.205.7.3.el8uek | [ELSA-2021-9457](https://patchblox.com/security/data/fix/linux/elsa-2021-9457.md) | Sep 22, 2021 |
| Linux | kernel-uek-tools ol 8 | 0:5.4.17-2102.205.7.3.el7uek | [ELSA-2021-9457](https://patchblox.com/security/data/fix/linux/elsa-2021-9457.md) | Sep 22, 2021 |
| Linux | kernel-uek-tools-libs ol 8 | 0:5.4.17-2102.205.7.3.el7uek | [ELSA-2021-9457](https://patchblox.com/security/data/fix/linux/elsa-2021-9457.md) | Sep 22, 2021 |
| Linux | linux Debian 12.15 (bookworm) | 5.14.6-1 | [DEBIAN-CVE-2021-3739](https://patchblox.com/security/data/fix/linux/debian-cve-2021-3739.md) | Mar 10, 2022 |
| Linux | linux Debian 13.5 (trixie) | 5.14.6-1 | [DEBIAN-CVE-2021-3739](https://patchblox.com/security/data/fix/linux/debian-cve-2021-3739.md) | Mar 10, 2022 |
| Linux | linux Debian 14 | 5.14.6-1 | [DEBIAN-CVE-2021-3739](https://patchblox.com/security/data/fix/linux/debian-cve-2021-3739.md) | Mar 10, 2022 |
| Linux | perf ol 8 | 0:5.4.17-2102.205.7.3.el7uek | [ELSA-2021-9457](https://patchblox.com/security/data/fix/linux/elsa-2021-9457.md) | Sep 22, 2021 |
| Linux | python-perf ol 8 | 0:5.4.17-2102.205.7.3.el7uek | [ELSA-2021-9457](https://patchblox.com/security/data/fix/linux/elsa-2021-9457.md) | Sep 22, 2021 |

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