Re: CVE-2024-26602: sched/membarrier: reduce the ability to hammer on sys_membarrier

From: Thorsten Leemhuis
Date: Sun Feb 25 2024 - 04:31:37 EST


On 24.02.24 15:57, Greg Kroah-Hartman wrote:
> Description
> ===========
>
> In the Linux kernel, the following vulnerability has been resolved:
>
> sched/membarrier: reduce the ability to hammer on sys_membarrier
>
> On some systems, sys_membarrier can be very expensive, causing overall
> slowdowns for everything. So put a lock on the path in order to
> serialize the accesses to prevent the ability for this to be called at
> too high of a frequency and saturate the machine.
>
> The Linux kernel CVE team has assigned CVE-2024-26602 to this issue.
>
>
> Affected and fixed versions
> ===========================
>
> Issue introduced in 4.14 with commit c5f58bd58f43 and fixed in 4.19.307 with commit 3cd139875e9a
> Issue introduced in 4.14 with commit c5f58bd58f43 and fixed in 5.4.269 with commit 2441a64070b8
> Issue introduced in 4.14 with commit c5f58bd58f43 and fixed in 5.10.210 with commit db896bbe4a9c
> Issue introduced in 4.14 with commit c5f58bd58f43 and fixed in 5.15.149 with commit 50fb4e17df31
> Issue introduced in 4.14 with commit c5f58bd58f43 and fixed in 6.1.79 with commit 24ec7504a08a
> Issue introduced in 4.14 with commit c5f58bd58f43 and fixed in 6.6.18 with commit b6a2a9cbb675
> Issue introduced in 4.14 with commit c5f58bd58f43 and fixed in 6.7.6 with commit c5b2063c65d0
>
> Please see [...]
Greg, JFYI, I noticed that this announcement did not refer to the fix in
mainline (944d5fe50f3f03 ("sched/membarrier: reduce the ability to
hammer on sys_membarrier")) while most of the others do that. I don't
care at all, just noticed this by chance and wanted to let you know in
case it's due to a bug in a script or something. I hope there is not a
good reason for that difference I just failed to spot... (if that's the
case: apologies in advance for the noise!).

Ciao, Thorsten