Re: CVE-2018-10938: Linux kernel: net: infinite loop in net/ipv4/cipso_ipv4.c:cipso_v4_optptr() allows a remote DoS

[Greg KH <greg () kroah com>]

On Mon, Aug 27, 2018 at 05:25:15AM -0400, Vladis Dronov wrote:
> Heololo,
>
> A flaw was found in the Linux kernel present since v4.0-rc1 and through v4.13-rc4.
> A crafted network packet sent remotely by an attacker may force the kernel to enter
> an infinite loop in the cipso_v4_optptr() function in net/ipv4/cipso_ipv4.c leading
> to a denial-of-service.
>
> All the kernels with the cipso_v4_optptr() function which have not backported
> the upstream commit 40413955ee26 are vulnerable.
>
> Thanks to Yves Younan from Cisco for mentioning this.
>
> References:
>
> https://bugzilla.redhat.com/show_bug.cgi?id=1622404
>
> Upstream Patch introduced the flaw:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=04f81f0154e4bf002be6f4d85668ce1257efa4d9
>
> Upstream Patch fixed the flaw:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=40413955ee265a5e42f710940ec78f5450d49149

To be more specific here (as I complained about the other CVE report for
the kernel a minute ago), this means currently the 3.18.y, 4.4.y, and
4.9.y kernels are vulnerable to this problem.  I'll go backport the
patch above now to those trees and it will be included in the next
releases of these kernel trees later this week.

Thanks for posting this here, it is helpful, and I appreciate it.

greg k-h