Description
The do_remount function in fs/namespace.c in the Linux kernel through 3.16.1 does not maintain the MNT_LOCK_READONLY bit across a remount of a bind mount, which allows local users to bypass an intended read-only restriction and defeat certain sandbox protection mechanisms via a "mount -o remount" command within a user namespace.
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 | 3.16.2-1 | — |
| Debian 13 | linux | 3.16.2-1 | — |
| Debian 12 | linux | 3.16.2-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | linux | 3.13.0-34.60 | USN-2318-1 |
Advisories 1
- USN-2318-1 linux vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
References
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=a6138db815df5ee542d848318e5dae681590fccd
- USN-2318-1 vendor-advisory
- 69214 vdb-entry
- https://bugzilla.redhat.com/show_bug.cgi?id=1129662
- https://github.com/torvalds/linux/commit/a6138db815df5ee542d848318e5dae681590fccd
- [oss-security] 20140813 Re: CVE Request: ro bind mount bypass using user namespaces mailing-list
- USN-2317-1 vendor-advisory