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Re: CVE-2021-20177 kernel: iptables string match rule could result in kernel panic


From: Greg KH <greg () kroah com>
Date: Tue, 12 Jan 2021 09:04:49 +0100

On Tue, Jan 12, 2021 at 04:58:07PM +1000, Wade Mealing wrote:
Gday,

A flaw was found in the Linux kernels implementation of string matching
within a packet. A privileged user
(with root or CAP_NET_ADMIN ) when inserting iptables rules could insert a
rule which can panic the system.

Likely a user with these permissions could do worse, however it crashes the
system (DOS) and the user is going to have a bad day
especially if the rule is inserted and restored on every boot.

At this time it doesn't affect RHEL releases, and there are fixes already
in multiple upstream trees.

Thanks,

Wade Mealing

Upstream patch:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ca58fbe06c54

Upstream bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=209823

Red Hat Bugzilla:
https://bugzilla.redhat.com/show_bug.cgi?id=1914719

I still do not understand why you report issues that are fixed over a
year ago (October 2019) and assign them a CVE like this.  Who does this
help out?  And what about the thousands of other issues that are fixed
in the kernel and not assigned a CVE like this, are they somehow not as
important to your group?

What determines what you want to give a CVE to and what you do not?

thanks,

greg k-h


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