bpf: Fix UAF via mismatching bpf_prog/attachment RCU flavors

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix UAF via mismatching bpf_prog/attachment RCU flavors Uprobes always use bpf_prog_run_array_uprobe() under tasks-trace-RCU protection. But it is possible to attach a non-sleepable BPF program to a uprobe, and non-sleepable BPF programs are freed via normal RCU (see __bpf_prog_put_noref()). This leads to UAF of the bpf_prog because a normal RCU grace period does not imply a tasks-trace-RCU grace period. Fix it by explicitly waiting for a tasks-trace-RCU grace period after removing the attachment of a bpf_prog to a perf_event.

References

• https://git.kernel.org/stable/c/9245459a992d22fe0e92e988f49db1fec82c184a
• https://git.kernel.org/stable/c/f9f85df30118f3f4112761e6682fc60ebcce23e5
• https://git.kernel.org/stable/c/9b53d2c2a38a1effc341d99be3f99fa7ef17047d
• https://git.kernel.org/stable/c/ef1b808e3b7c98612feceedf985c2fbbeb28f956