In the Linux kernel, the following vulnerability has been resolved:
bpf,perf: Fix invalid progarray access in perfeventdetachbpf_prog
Syzbot reported [1] crash that happens for following tracing scenario:
attached process forks -> chid creates inherited event
the new child event shares the parent's bpf program and tpevent (hence progarray) which is global for tracepoint
exit both process and its child -> release both events
The fix makes sure the perfeventdetachbpfprog 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