Description
The do_umount function in fs/namespace.c in the Linux kernel through 3.17 does not require the CAP_SYS_ADMIN capability for do_remount_sb calls that change the root filesystem to read-only, which allows local users to cause a denial of service (loss of writability) by making certain unshare system calls, clearing the / MNT_LOCKED flag, and making an MNT_FORCE umount system call.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 3.16.7-1 | — |
| Debian 13 | linux | 3.16.7-1 | — |
| Debian 12 | linux | 3.16.7-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-riscv +6 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +2 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +4 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +3 | No fix yet | — |
| Ubuntu 14.04 LTS | linux | 3.13.0-40.69 | USN-2420-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | linux-azure-fde-5.15 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | kernel-rt +10 | 3.10.0-693.rt56.617.el7 | RHSA-2017:2077 |
| RHEL 7 | perf +17 | 3.10.0-693.el7 | RHSA-2017:1842 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | dtrace-modules-3.8.13-68.el6uek | 0.4.3-4.el6 | ELSA-2015-3012 |
| Oracle Linux 7 | dtrace-modules-3.8.13-68.el7uek | 0.4.3-4.el7 | ELSA-2015-3012 |
| Oracle Linux 7 | kernel-uek +5 | 3.8.13-68.el7uek | ELSA-2015-3012 |
| Oracle Linux 7 | perf +11 | 3.10.0-693.el7 | ELSA-2017-1842 |
Advisories 5
- RHSA-2017:2077 Red Hat Security Advisory: kernel-rt security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jul 1, 2026
- RHSA-2017:1842 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jul 1, 2026
- USN-2420-1 linux vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- ELSA-2017-1842 Important: kernel security, bug fix, and enhancement update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Aug 7, 2017
- ELSA-2015-3012 Important: Unbreakable Enterprise kernel security and bugfix update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Mar 19, 2015
References
- USN-2418-1 vendor-advisory
- 61145 third-party-advisory
- linux-kernel-cve20147975-dos(96994) vdb-entry
- USN-2416-1 vendor-advisory
- USN-2417-1 vendor-advisory
- USN-2415-1 vendor-advisory
- USN-2419-1 vendor-advisory
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=0ef3a56b1c466629cd0bf482b09c7b0e5a085bb5
- 1031180 vdb-entry
- 60174 third-party-advisory
- USN-2421-1 vendor-advisory
- USN-2420-1 vendor-advisory
- RHSA-2017:2077 vendor-advisory
- RHSA-2017:1842 vendor-advisory
- 62633 third-party-advisory
- [oss-security] 20141008 CVE-2014-7975: 0-day umount denial of service mailing-list
- 62634 third-party-advisory
- [stable] 20141008 [PATCH] fs: Add a missing permission check to do_umount mailing-list
- 70314 vdb-entry
- https://bugzilla.redhat.com/show_bug.cgi?id=1151108