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commit978c4486ccupstream. Syzbot reported [1] crash that happens for following tracing scenario: - create tracepoint perf event with attr.inherit=1, attach it to the process and set bpf program to it - attached process forks -> chid creates inherited event the new child event shares the parent's bpf program and tp_event (hence prog_array) which is global for tracepoint - exit both process and its child -> release both events - first perf_event_detach_bpf_prog call will release tp_event->prog_array and second perf_event_detach_bpf_prog will crash, because tp_event->prog_array is NULL The fix makes sure the perf_event_detach_bpf_prog checks prog_array is valid before it tries to remove the bpf program from it. [1] https://lore.kernel.org/bpf/Z1MR6dCIKajNS6nU@krava/T/#m91dbf0688221ec7a7fc95e896a7ef9ff93b0b8ad Fixes:0ee288e69d("bpf,perf: Fix perf_event_detach_bpf_prog error handling") Reported-by: syzbot+2e0d2840414ce817aaac@syzkaller.appspotmail.com Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241208142507.1207698-1-jolsa@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>