Description
The qdisc_notify function in net/sched/sch_api.c in the Linux kernel before 2.6.35 does not prevent tc_fill_qdisc function calls referencing builtin (aka CQ_F_BUILTIN) Qdisc structures, which allows local users to cause a denial of service (NULL pointer dereference and OOPS) or possibly have unspecified other impact via a crafted 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 6.0 | linux-2.6 | 2.6.32-35squeeze1 | DSA-2303-1 |
| Debian 5.0 | linux-2.6 | 2.6.26-26lenny4 | DSA-2310-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 5 | kernel +12 | 2.6.18-238.21.1.el5 | RHSA-2011:1163, RHSA-2011:1065 |
Advisories 4
- RHSA-2011:1065 Red Hat Security Advisory: Red Hat Enterprise Linux 5.7 kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-2303-1 linux-2.6 - several issues Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-2310-1 linux-2.6 - several issues Debian Security (DSA / DLA) · Mar 9, 2026
- RHSA-2011:1163 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Feb 19, 2026
References
- https://bugzilla.redhat.com/show_bug.cgi?id=720552
- RHSA-2011:1065 vendor-advisory
- [netdev] 20100521 tc: RTM_GETQDISC causes kernel OOPS mailing-list
- http://mirror.anl.gov/pub/linux/kernel/v2.6/ChangeLog-2.6.35
- RHSA-2011:1163 vendor-advisory
- [oss-security] 20110712 CVE-2011-2525 kernel: kernel: net_sched: fix qdisc_notify() mailing-list
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=53b0f08042f04813cd1a7473dacd3edfacb28eb3