CVE-2010-2495: Null Pointer Dereference
Description of problem: When transmitting L2TP frames, we derive the outgoing interface's UDP checksum hardware assist capabilities from the tunnel dst dev. This can sometimes be NULL, especially when routing protocols are used and routing changes occur. This patch just checks for NULL dst or dev pointers when checking for netdev hardware assist features. BUG: unable to handle kernel NULL pointer dereference at 0000000c IP: [<f89d074c>] pppol2tpxmit+0x341/0x4da [pppol2tp] pde = 00000000 Oops: 0000 [#1] SMP last sysfs file: /sys/class/net/lo/operstate Modules linked in: pppol2tp pppox pppgeneric slhc ipv6 dummy loop sndhdacodecatihdmi sndhdaintel sndhdacodec snd [...] Code: 8d 45 08 f0 ff 45 08 89 6b 08 c7 43 68 7e fb 9c f8 8a 45 24 83 e0 0c 3c 04 75 09 80 63 64 f3 e9 b4 00 00 00 8b 43 1 EIP: [<f89d074c>] pppol2tpxmit+0x341/0x4da [pppol2tp] SS:ESP 0068:f70a9cac CR2: 000000000000000c
Introduced in ffcebb16 (v2.6.29-rc1~581), fixed in 3feec909 (fixed in v2.6.34-rc2).
Upstream commit: http://git.kernel.org/linus/ffcebb16 http://git.kernel.org/linus/3feec909
Other sources
The pppol2tpxmit function in drivers/net/pppol2tp.c in the L2TP implementation in the Linux kernel before 2.6.34 does not properly validate certain values associated with an interface, which allows attackers to cause a denial of service (NULL pointer dereference and OOPS) or possibly have unspecified other impact via vectors related to a routing change.
— Launchpad
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2010-2495?
The severity of CVE-2010-2495 is classified as moderate, affecting the stability of L2TP frame transmission.
What systems are affected by CVE-2010-2495?
CVE-2010-2495 affects various versions of the Linux kernel, Ubuntu Linux, and SUSE Linux Enterprise products.
How do I fix CVE-2010-2495?
The recommended fix for CVE-2010-2495 is to upgrade to an updated version of the affected Linux kernel or relevant distributions.
Is there a workaround for CVE-2010-2495?
Currently, there are no known workarounds for CVE-2010-2495, so applying patches is essential.
When was CVE-2010-2495 disclosed?
CVE-2010-2495 was disclosed in August 2010, highlighting an issue with L2TP frame transmission.