net/ipv4/udp.c in the Linux kernel before 2.6.29.1 performs an unlocking step in certain incorrect circumstances, which allows local users to cause a denial of service (panic) by reading zero bytes from the /proc/net/udp file and unspecified other files, related to the "udp seq_file infrastructure."

References

• https://nvd.nist.gov/vuln/detail/CVE-2009-1243
• https://exchange.xforce.ibmcloud.com/vulnerabilities/49595
• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=30842f2989aacfaba3ccb39829b3417be9313dbe
• http://openwall.com/lists/oss-security/2009/04/01/4
• http://secunia.com/advisories/34478
• http://vigilance.fr/vulnerability/Linux-kernel-denial-of-service-via-proc-net-udp-8586
• http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.29.1
• http://www.securityfocus.com/bid/34329
• http://www.vupen.com/english/advisories/2009/0924
• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=30842f2989aacfaba3ccb39829b3417be9313dbe