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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2009-4272
• https://bugzilla.redhat.com/show_bug.cgi?id=545411
• https://exchange.xforce.ibmcloud.com/vulnerabilities/55808
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11167
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A7026
• https://rhn.redhat.com/errata/RHSA-2010-0046.html
• https://rhn.redhat.com/errata/RHSA-2010-0095.html
• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=73e42897e8e5619eacb787d2ce69be12f47cfc21
• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=b6280b47a7a42970d098a3059f4ebe7e55e90d8d
• http://support.avaya.com/css/P8/documents/100073666
• http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.31
• http://www.openwall.com/lists/oss-security/2010/01/20/1
• http://www.openwall.com/lists/oss-security/2010/01/20/6
• https://access.redhat.com/errata/RHSA-2010:0046
• https://access.redhat.com/errata/RHSA-2010:0095
• https://access.redhat.com/security/cve/CVE-2009-4272
• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=73e42897e8e5619eacb787d2ce69be12f47cfc21
• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=b6280b47a7a42970d098a3059f4ebe7e55e90d8d