Re: [6.1.y][6.6.y] uprobes: Fix race in uprobe_free_utask

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Mar 04, 2025 at 10:33:24AM +0000, Christian Simon wrote:
> Dear stable team,
> 
> I noticed that cfa7f3d2c526 ("perf,x86: avoid missing caller address in stack traces captured in uprobe"), got backported into 6.1.113 and 6.6.55, but it contains a race condition which Jiri Olsa has fixed in mainline b583ef82b671 ("uprobes: Fix race in uprobe_free_utask"). I think this should be backported into those stable branches.
> 
> #regzbot title: uprobes: Fix race in uprobe_free_utask
> #regzbot introduced: cfa7f3d2c526
> #regzbot link: https://lore.kernel.org/all/20250109141440.2692173-1-jolsa@kernel.org/
> 
> Link: https://lore.kernel.org/all/20250109141440.2692173-1-jolsa@kernel.org/
> 
> Note: Sorry if I am using the wrong process/form/format, I tried to follow "Option 2" from the stable-kernel-rules.html.

As the patch does not apply cleanly to those kernels, how did you test
this?

Can you provide some working, and tested, patches for this?  We'll be
glad to queue them up if so.

thanks,

greg k-h