Kernel oops with 6.14 when enabling TLS

[Matthew Wilcox]

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.