Re: [PATCH stable 6.6] lib/buildid: Handle memfd_secret() files in build_id_parse()

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Mar 12, 2025 at 11:03:18AM +0800, Chen Linxuan wrote:
> Greg KH <gregkh@linuxfoundation.org> 于2025年3月11日周二 19:14写道：
> >
> > On Tue, Mar 11, 2025 at 06:05:55PM +0800, Chen Linxuan wrote:
> > > Backport of a similar change from commit 5ac9b4e935df ("lib/buildid:
> > > Handle memfd_secret() files in build_id_parse()") to address an issue
> > > where accessing secret memfd contents through build_id_parse() would
> > > trigger faults.
> > >
> > > Original report and repro can be found in [0].
> > >
> > >   [0] https://lore.kernel.org/bpf/ZwyG8Uro%2FSyTXAni@ly-workstation/
> > >
> > > This repro will cause BUG: unable to handle kernel paging request in
> > > build_id_parse in 5.15/6.1/6.6.
> > >
> > > Some other discussions can be found in [1].
> > >
> > >   [1] https://lore.kernel.org/bpf/20241104175256.2327164-1-jolsa@kernel.org/T/#u
> > >
> > > Cc: stable@vger.kernel.org
> > > Fixes: 88a16a130933 ("perf: Add build id data in mmap2 event")
> > > Signed-off-by: Chen Linxuan <chenlinxuan@deepin.org>
> >
> > You dropped all the original signed-off-by and changelog text.  Just
> 
> The original commit is based on commit de3ec364c3c3 ("lib/buildid: add
> single folio-based file reader abstraction"). `git cherry-pick` result lots of
> conflicts. So I rewrite same logic on old code.

Then keep the original commit message, tell us what the original commit
id was, and then put in the signed-off-by area what you changed.

There's loads of examples of backports in this format on the stable
mailing list, look at them for what to do.

thanks,

greg k-h