Kernel oops with 6.14 when enabling TLS

[Hannes Reinecke]

On 3/3/25 14:57, Matthew Wilcox wrote:
> On Mon, Mar 03, 2025 at 12:06:18PM +0100, Hannes Reinecke wrote:
>> On 3/3/25 08:48, Hannes Reinecke wrote:
>>> On 2/28/25 11:47, Hannes Reinecke wrote:
>>>> Hi Sagi,
>>>>
>>>> enabling TLS on latest linus tree reliably crashes my system:
>>>>
>>>> [  487.018058] ------------[ cut here ]------------
>>>> [  487.024046] WARNING: CPU: 9 PID: 6159 at mm/slub.c:4719
>>>> free_large_kmalloc+0x15/0xa0
>> [ .. ]
>>>>
>>>> Haven't found a culprit for that one for now, started bisecting.
>>>> Just wanted to report that as a heads-up, maybe you have some idea.
>>>>
>>>
>>> bisect is pointing to
>>> 9aec2fb0fd5e ("slab: allocate frozen pages")
>>> and, indeed, reverting this patch on top of linus current resolves
>>> the issue.
>>>
>>> Sorry Matthew.
>>>
>> It's getting even worse; after reverting above patch I'm getting a crash
>> here:
> 
> If you revert that, you also need to revert 8c6e2d122b71.
> 
> But let me dig into the original problem.  The fact that it's
> kmalloc_large might be a clue.

Let me know if you need more details.

Incidentally, there's a blktest unit for TLS now:

https://github.com/osandov/blktests/pull/158

which should allow you to recreate the issue locally.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare at suse.com                               +49 911 74053 688
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