bpf: Do not audit capability check in do_jit()

JIRA: https://issues.redhat.com/browse/RHEL-108805
Upstream Status: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git

commit 881a9c9
Author: Ondrej Mosnacek <omosnace@redhat.com>
Date:   Tue Oct 21 14:27:58 2025 +0200

    bpf: Do not audit capability check in do_jit()

    The failure of this check only results in a security mitigation being
    applied, slightly affecting performance of the compiled BPF program. It
    doesn't result in a failed syscall, an thus auditing a failed LSM
    permission check for it is unwanted. For example with SELinux, it causes
    a denial to be reported for confined processes running as root, which
    tends to be flagged as a problem to be fixed in the policy. Yet
    dontauditing or allowing CAP_SYS_ADMIN to the domain may not be
    desirable, as it would allow/silence also other checks - either going
    against the principle of least privilege or making debugging potentially
    harder.

    Fix it by changing it from capable() to ns_capable_noaudit(), which
    instructs the LSMs to not audit the resulting denials.

    Link: https://bugzilla.redhat.com/show_bug.cgi?id=2369326
    Fixes: d4e89d2 ("x86/bpf: Call branch history clearing sequence on exit")
    Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
    Reviewed-by: Paul Moore <paul@paul-moore.com>
    Link: https://lore.kernel.org/r/20251021122758.2659513-1-omosnace@redhat.com
    Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>

Author: WOnder93

arch/x86/net/bpf_jit_comp.c

@@ -2584,7 +2584,7 @@ st:			if (is_imm8(insn->off))
 			/* Update cleanup_addr */
 			ctx->cleanup_addr = proglen;
 			if (bpf_prog_was_classic(bpf_prog) &&
-			    !capable(CAP_SYS_ADMIN)) {
+			    !ns_capable_noaudit(&init_user_ns, CAP_SYS_ADMIN)) {
 				u8 *ip = image + addrs[i - 1];
 
 				if (emit_spectre_bhb_barrier(&prog, ip, bpf_prog))