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

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.

Best regards, Christian