Re: CVE-2020-25641 kernel: soft lockup when submitting zero length bvecs.

                							

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Re: CVE-2020-25641 kernel: soft lockup when submitting zero length bvecs.

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From: Greg KH &lt;greg () kroah com&gt;

Date: Wed, 30 Sep 2020 08:32:54 +0200

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On Wed, Sep 30, 2020 at 10:35:56AM +1000, Wade Mealing wrote:
Gday,

A flaw was found in the Linux kernels implementation of biovec usage.  A
zero-length biovec request issued to the block subsystem could cause the
kernel to enter an infinite loop causing a denial of service. An attacker
with a local account can issue requests to a block device can cause a
denial of service.

This has been assigned CVE-2020-25641,

According to the fix commits "Introduced in":
# git tag --contains 1bdc76aea115 | head -n 1
v4.10

That's odd, and not the best way to do this, the commit really showed up
in 4.8-rc1:
        $ git describe --contains 1bdc76aea115
        v4.8-rc1~162^2~21

You forgot to sort by "version", which is what you need to do if you
want to try to look at tags, but then it's still a bit off:
        $ git tag --contains 1bdc76aea115 | sort -V | head -n 10
        v4.8
        v4.8-rc1
        v4.8-rc2
        v4.8-rc3
        v4.8-rc4
        v4.8-rc5
        v4.8-rc6
        v4.8-rc7
        v4.8-rc8
        v4.9

hope this helps,

greg k-h

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CVE-2020-25641 kernel: soft lockup when submitting zero length bvecs. Wade Mealing (Sep 29)

Re: CVE-2020-25641 kernel: soft lockup when submitting zero length bvecs. Greg KH (Sep 29)

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