arm64: bpf: Only mitigate cBPF programs loaded by unprivileged users

commit f300769ead032513a68e4a02e806393402e626f8 upstream.

Support for eBPF programs loaded by unprivileged users is typically
disabled. This means only cBPF programs need to be mitigated for BHB.

In addition, only mitigate cBPF programs that were loaded by an
unprivileged user. Privileged users can also load the same program
via eBPF, making the mitigation pointless.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
James Morse
2025-04-29 16:03:38 +01:00
committed by Greg Kroah-Hartman
parent 42a20cf510
commit 80251f6202

View File

@@ -666,6 +666,9 @@ static void __maybe_unused build_bhb_mitigation(struct jit_ctx *ctx)
arm64_get_spectre_v2_state() == SPECTRE_VULNERABLE)
return;
if (capable(CAP_SYS_ADMIN))
return;
if (supports_clearbhb(SCOPE_SYSTEM)) {
emit(aarch64_insn_gen_hint(AARCH64_INSN_HINT_CLEARBHB), ctx);
return;