Re: Warnings and errors in drm_mode_config_cleanup when booting 6.19.10 and 7.0-rc5

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Apr 06, 2026 at 03:54:39AM -0400, Matt Fagnani wrote:
> On 2026-04-02 08:12, Greg KH wrote:
> > On Sat, Mar 28, 2026 at 11:52:48AM +0100, Thorsten Leemhuis wrote:
> > > Matt, thx for the report.
> > > 
> > > On 3/28/26 11:30, Matt Fagnani wrote:
> > > > I could try to bisect. The commit
> > > > e493c135980f90c20308d1a98f2e0d1223951e94 drm: Fix use-after-free on
> > > > framebuffers and property blobs when calling drm_dev_unplug was included
> > > > in 6.19.10 and changed drm_mode_config_cleanup https://git.kernel.org/
> > > > pub/scm/linux/kernel/git/stable/linux.git/commit/?
> > > > h=linux-6.19.y&id=e493c135980f90c20308d1a98f2e0d1223951e94
> > > Did a quick search. Turns out this is mainline commit 6bee098b914176
> > > ("drm: Fix use-after-free on framebuffers and property blobs when
> > > calling drm_dev_unplug") -- and when searching for that (FWIW, this is
> > > not widely known, but that is really helpful in case like this, as the
> > > mainline commit id is way more relevant) is turns out that is in the
> > > process of getting reverted:
> > > 
> > > See https://lore.kernel.org/all/20260326082217.39941-2-dev@lankhorst.se/
> > > or 45ebe43ea00d6b ("Revert "drm: Fix use-after-free on framebuffers and
> > > property blobs when calling drm_dev_unplug"") [next-20260327
> > > (pending-fixes)].
> > > 
> > > Sasha and Greg: you might want to make sure to pick this up.
> > When it shows up in a Linus-released kernel, can someone remind us?
> > 
> > thanks,
> > 
> > greg k-h
> 
> 7.0-rc7 https://lwn.net/Articles/1066405/ had the patch Revert "drm: Fix
> use-after-free on framebuffers and property blobs when calling
> drm_dev_unplug" https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v7.0-rc7&id=45ebe43ea00d6b9f5b3e0db9c35b8ca2a96b7e70 Thanks.

Does not apply on 6.6.y or 6.1.y, so can someone provide a working
backport for those branches?

thanks,

greg k-h