Description
The create_user_ns function in kernel/user_namespace.c in the Linux kernel before 3.8.6 does not check whether a chroot directory exists that differs from the namespace root directory, which allows local users to bypass intended filesystem restrictions via a crafted clone 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 | 3.8.11-1 | — |
| Debian 13 | linux | 3.8.11-1 | — |
| Debian 12 | linux | 3.8.11-1 | — |
References
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=3151527ee007b73a0ebd296010f1c0454a919c7d
- https://github.com/torvalds/linux/commit/3151527ee007b73a0ebd296010f1c0454a919c7d
- [oss-security] 20130416 Re: Re: Summary of security bugs (now fixed) in user namespaces mailing-list
- http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.8.6