Description
The __tun_chr_ioctl function in drivers/net/tun.c in the Linux kernel before 3.6 does not initialize a certain structure, which allows local users to obtain sensitive information from kernel stack memory via a crafted application.
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 | 3.2.29-1 | — |
| Debian 13 | linux | 3.2.29-1 | — |
| Debian 12 | linux | 3.2.29-1 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6 | perf +15 | 2.6.32-358.6.1.el6 | RHSA-2013:0744 |
| RHEL 5 | kernel +12 | 2.6.18-348.4.1.el5 | RHSA-2013:0747 |
Advisories 2
- RHSA-2013:0744 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2013:0747 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Nov 22, 2025
References
- MDVSA-2013:176 vendor-advisory
- [oss-security] 20130305 CVE Requests (maybe): Linux kernel: various info leaks, some NULL ptr derefs mailing-list
- https://github.com/torvalds/linux/commit/a117dacde0288f3ec60b6e5bcedae8fa37ee0dfc
- https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.6.bz2
- RHSA-2013:0744 vendor-advisory
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=a117dacde0288f3ec60b6e5bcedae8fa37ee0dfc