On Wed, Dec 4, 2019 at 9:08 AM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
> diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
> index c89c6495983d..32a5db900f47 100644
> --- a/include/uapi/linux/audit.h
> +++ b/include/uapi/linux/audit.h
> @@ -116,6 +116,7 @@
> #define AUDIT_FANOTIFY 1331 /* Fanotify access decision */
> #define AUDIT_TIME_INJOFFSET 1332 /* Timekeeping offset injected */
> #define AUDIT_TIME_ADJNTPVAL 1333 /* NTP value adjustment */
> +#define AUDIT_BPF 1334 /* BPF subsystem */
>
> #define AUDIT_AVC 1400 /* SE Linux avc denial or grant */
> #define AUDIT_SELINUX_ERR 1401 /* Internal SE Linux Errors */
> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
> index e3461ec59570..81f1a6308aa8 100644
> --- a/kernel/bpf/syscall.c
> +++ b/kernel/bpf/syscall.c
> @@ -23,6 +23,7 @@
> #include <linux/timekeeping.h>
> #include <linux/ctype.h>
> #include <linux/nospec.h>
> +#include <linux/audit.h>
> #include <uapi/linux/btf.h>
>
> #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
> @@ -1306,6 +1307,33 @@ static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
> return 0;
> }
>
> +enum bpf_audit {
> + BPF_AUDIT_LOAD,
> + BPF_AUDIT_UNLOAD,
> +};
> +
> +static const char * const bpf_audit_str[] = {
> + [BPF_AUDIT_LOAD] = "LOAD",
> + [BPF_AUDIT_UNLOAD] = "UNLOAD",
> +};
> +
> +static void bpf_audit_prog(const struct bpf_prog *prog, enum bpf_audit op)
> +{
> + struct audit_context *ctx = NULL;
> + struct audit_buffer *ab;
> +
> + if (audit_enabled == AUDIT_OFF)
> + return;
> + if (op == BPF_AUDIT_LOAD)
> + ctx = audit_context();
> + ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
> + if (unlikely(!ab))
> + return;
> + audit_log_format(ab, "prog-id=%u op=%s",
> + prog->aux->id, bpf_audit_str[op]);
> + audit_log_end(ab);
> +}
As mentioned previously, I still think it might be a good idea to
ensure "op" is within the bounds of bpf_audit_str, but the audit bits
look reasonable to me.
> int __bpf_prog_charge(struct user_struct *user, u32 pages)
> {
> unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
> @@ -1421,6 +1449,7 @@ static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
> {
> if (atomic64_dec_and_test(&prog->aux->refcnt)) {
> perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
> + bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
> /* bpf_prog_free_id() must be called first */
> bpf_prog_free_id(prog, do_idr_lock);
> __bpf_prog_put_noref(prog, true);
> @@ -1830,6 +1859,7 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
> */
> bpf_prog_kallsyms_add(prog);
> perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
> + bpf_audit_prog(prog, BPF_AUDIT_LOAD);
>
> err = bpf_prog_new_fd(prog);
> if (err < 0)
> --
> 2.23.0
--
paul moore
www.paul-moore.com
