Description
A certain Red Hat patch for net/ipv4/route.c in the Linux kernel 2.6.18 on Red Hat Enterprise Linux (RHEL) 5 allows remote attackers to cause a denial of service (deadlock) via crafted packets that force collisions in the IPv4 routing hash table, and trigger a routing "emergency" in which a hash chain is too long. NOTE: this is related to an issue in the Linux kernel before 2.6.31, when the kernel routing cache is disabled, involving an uninitialized pointer and a panic.
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.
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 5 | kernel +11 | 2.6.18-164.11.1.el5 | RHSA-2010:0046 |
| RHEL 5 | rhev-hypervisor +1 | 5.4-2.1.8.el5_4rhev2_1 | RHSA-2010:0095 |
Advisories 2
- RHSA-2010:0095 Red Hat Security Advisory: rhev-hypervisor security and bug fix update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- RHSA-2010:0046 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jun 29, 2026
References
- https://bugzilla.redhat.com/show_bug.cgi?id=545411
- http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.31
- http://support.avaya.com/css/P8/documents/100073666
- linux-kernel-routing-dos(55808) vdb-entry
- [oss-security] 20100120 CVE-2009-4272 kernel: emergency route cache flushing leads to node deadlock mailing-list
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=b6280b47a7a42970d098a3059f4ebe7e55e90d8d
- oval:org.mitre.oval:def:11167 vdb-entry signature
- RHSA-2010:0095 vendor-advisory
- oval:org.mitre.oval:def:7026 vdb-entry signature
- RHSA-2010:0046 vendor-advisory
- [oss-security] 20100120 Re: CVE-2009-4272 kernel: emergency route cache flushing leads to node deadlock mailing-list
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=73e42897e8e5619eacb787d2ce69be12f47cfc21