arm64 access to userspace addresses in bpf and kprobes is broken, because kernelspace address accessors are always used, and won't work for userspace.
The fix in upstream relies on new kernel BPF API which does not exist in v5.4. The patches here deviate from their upstream sources.
I am not 100% clear on the best way to post a patch series to stable, that's not a direct cherry-pick from upstream. Please let me know if corrections are needed.
Thank you!
Tsahi Zidenberg (2): bpf: fix userspace access for bpf_probe_read{, str}() tracing/kprobes: handle userspace access on unified probes.
arch/arm/Kconfig | 1 + arch/arm64/Kconfig | 1 + arch/powerpc/Kconfig | 1 + arch/x86/Kconfig | 1 + init/Kconfig | 3 +++ kernel/trace/bpf_trace.c | 18 ++++++++++++++++++ kernel/trace/trace_kprobe.c | 15 +++++++++++++++ 7 files changed, 40 insertions(+)