* Suren Baghdasaryan <surenb@xxxxxxxxxx> [250110 16:25]: > On Fri, Jan 10, 2025 at 11:56 AM Liam R. Howlett > <Liam.Howlett@xxxxxxxxxx> wrote: > > > > * David Hildenbrand <david@xxxxxxxxxx> [250110 11:31]: > > > On 10.01.25 17:27, Matthew Wilcox wrote: > > > > On Fri, Jan 10, 2025 at 05:19:54PM +0100, David Hildenbrand wrote: > > > > > On 10.01.25 17:14, Matthew Wilcox wrote: > > > > > > On Fri, Jan 10, 2025 at 04:48:03PM +0100, David Hildenbrand wrote: > > > > > > > If I would have to guess, I would assume that we have a refcount issue such > > > > > > > that we succeed in splitting a folio while concurrently mapping it. > > > > > > > > > > > > That would seem hard to accomplish, because both hold the folio lock, > > > > > > so it wouldn't be just a refcount bug but also a locking bug. Not sure > > > > > > what this is though. > > > > > > > > > > Yeah, but we also have > > > > > > > > > > https://lkml.kernel.org/r/6774bf44.050a0220.25abdd.098a.GAE@xxxxxxxxxx > > > > > > > > That one is a UAF on the vma, so it's either a different issue, or the > > > > problem is with the VMA refcount/lookup/..., not the folio refcount. > > > > cc'ing the relevant maintainers. > > > > > > Agreed, it's all a bit confusing. > > > > > > > This might involve Suren's patch set which changes the locking of the > > vmas. > > Possibly... The patchset in linux-next on Jan 1st was somewhat > different from the latest one. Yeah, I asked the bot to retest the latest unstable (which is still somewhat out of date..). I suspect it'll be okay now. We'll see what it comes back with. > > > > > Suren, if you respin and it's not too much trouble can you please make a > > git branch with the latest patches for easier review and testing? > > Ok, I'll see what I can do. Thanks, I appreciate it. Regards, Liam
